XJS - 6 vs 12 - which one to buy?
#61
01-27-2014, 12:04 PM
#62
01-28-2014, 07:00 AM
Good posting, and accurate, Allan.
I agree that a 4.0/5-speed would be a great choice (see post #3 in this thread).
Heck, any 4.0 XJS would the right choice for many would-be Jag owners.
But, agreeing on that (assuming most of us do) doesn't make the V12 a bad choice for all would-be owners. For some people the V12 is a *great* choice. That's all I'm tryin' to say
Like Jaguar itself, or Lucas electrics, I feel that the V12s are too harshly maligned. Often as not by those who haven't owned one, I think.
Cheers
DD
I agree that a 4.0/5-speed would be a great choice (see post #3 in this thread).
Heck, any 4.0 XJS would the right choice for many would-be Jag owners.
But, agreeing on that (assuming most of us do) doesn't make the V12 a bad choice for all would-be owners. For some people the V12 is a *great* choice. That's all I'm tryin' to say
Like Jaguar itself, or Lucas electrics, I feel that the V12s are too harshly maligned. Often as not by those who haven't owned one, I think.
Cheers
DD
I completely agree and as I said both are magnificent engines and both are very reliable if maintained properly. Yes the XJS is a big heavy car but it is imbued with remarkable levels of grip and the right suspension setup can be a revelation to how it handles.
I have given a ride to a number of V12 XJS owners in my Jag club and they have all been amazed at the difference, especially on the twisty bits. But the biggest compliments have come from E type owners, one of whom has a race pre-pared e-type and said "I thought the XJS wasn't supposed to be a sports car!!"
I have driven many, many miles in a V12 XJS and owned an XJ12 for a while so I am well aware of it's charms
#64
02-01-2014, 10:42 AM
I have enjoyed this discussion on V-12 vs 6. I have always felt that those that own the V-12 really get to know their cars in a very intimate way. What I mean by this is when you spend a lot of time and energy working on something (even just replacing a hose) it becomes personal. I also see this with the 6 owners who have done mods etc. like Reinaldo's 94 (if you have not taken the time to see all the quality mods done on this car you owe it to yourself to check it out ). Over the years I have worked on a few projects that took so much time and effort that I will never forget them.
I enjoy going to car shows and talking to the owners that actually rebuilt their cars. There is something very special about the bond that is developed between a person and a machine when that person knows every bolt on that vehicle. What I think so many of the newer vehicles are lacking today is that visual connection. Not only do so many of the newer vehicles today lack the visual cues on the exterior panels but, when you open the hood to see the wonderful power plant hiding under there you are greeted with a big cover of plastic. This is why my heart beats a bit faster when a see a chromed out XK inline 6 or V-12 Jaguar engine. What a work of art the older Jag engines are.
From my perspective Jaguar lost much of that visual connection when they went to the fuel injection set up on the 5.3 V-12 XJS. Not only did you loose the ability to see much of the engine in the XJS compartment but you were left viewing a layer of hoses and lines that would have made a NASA engineer in the 60's envious. I have a friend who has a series 3 E-type and I love not only being able to see much more of the V-12 with the bonnet up but I also enjoy seeing the 4 carbs with their chromed out covers. Even the 6 on the early XJS' was not made to be visually interesting. You got a black ribbed valve cover to look at with black spark plug wires-not much to grab your attention.
I was surprised at some of the comments I have gotten over the years about my 1995 4.0L. Most people today are not use to seeing large in line 6 motors and the large flat valve cover really makes the AJ16 look pretty massive. What I think makes the AJ16 stand out is the fact that Jag used silver to paint the valve cover and hid the wires. This is something I had not really thought about but I would hear over and over again at car shows how big the engine was on the 1995 even when I was parked next to a AJ6 motored car.
So I bring this all up to say how excited I am to see some of the XJS owners whether V-12 or 6 starting to put some focus on dressing up their engines. I really like what Jagzilla did with the colors and detail to the valve covers etc. which is such an eye catcher. Just nice to see both V-12 and inline 6 XJS's being taken care of and I always look forward to seeing both.
I enjoy going to car shows and talking to the owners that actually rebuilt their cars. There is something very special about the bond that is developed between a person and a machine when that person knows every bolt on that vehicle. What I think so many of the newer vehicles are lacking today is that visual connection. Not only do so many of the newer vehicles today lack the visual cues on the exterior panels but, when you open the hood to see the wonderful power plant hiding under there you are greeted with a big cover of plastic. This is why my heart beats a bit faster when a see a chromed out XK inline 6 or V-12 Jaguar engine. What a work of art the older Jag engines are.
From my perspective Jaguar lost much of that visual connection when they went to the fuel injection set up on the 5.3 V-12 XJS. Not only did you loose the ability to see much of the engine in the XJS compartment but you were left viewing a layer of hoses and lines that would have made a NASA engineer in the 60's envious. I have a friend who has a series 3 E-type and I love not only being able to see much more of the V-12 with the bonnet up but I also enjoy seeing the 4 carbs with their chromed out covers. Even the 6 on the early XJS' was not made to be visually interesting. You got a black ribbed valve cover to look at with black spark plug wires-not much to grab your attention.
I was surprised at some of the comments I have gotten over the years about my 1995 4.0L. Most people today are not use to seeing large in line 6 motors and the large flat valve cover really makes the AJ16 look pretty massive. What I think makes the AJ16 stand out is the fact that Jag used silver to paint the valve cover and hid the wires. This is something I had not really thought about but I would hear over and over again at car shows how big the engine was on the 1995 even when I was parked next to a AJ6 motored car.
So I bring this all up to say how excited I am to see some of the XJS owners whether V-12 or 6 starting to put some focus on dressing up their engines. I really like what Jagzilla did with the colors and detail to the valve covers etc. which is such an eye catcher. Just nice to see both V-12 and inline 6 XJS's being taken care of and I always look forward to seeing both.
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Forcedair1 (02-02-2014)
#65
02-01-2014, 11:06 AM
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Right. You don't own a Jaguar. You have a relationship with one
And, yes, V12 owners have to put more effort into the relationship ...but the car repays in more than equal measure.
As for engine beauty......
Jaguar has found their way, lost it, and found it again at various times over the years. The fuel injected v12s are indeed a nightmare of hoses clumped on top but when everything is sorted and cleaned even they're a bit awe inspiring in their own way.
Tastes vary, of course, but pesonally I don't go for the brightly painted/adorned V12s. Or any other engine, for that matter. I prefer a more business-like appearance. Clean, orderly, perhaps a few bits of lightly polished aluminum. The earlier Jag motors you mentioned have it. Handsome, not glitzy.
Yellow and red paint, and brightly colored plug wires, and chrome goodies.....it all screams "Rod and Custom" or "Hot Rod" to me. It just isn't Jaguar-ish IMHO.
Cheers
DD
And, yes, V12 owners have to put more effort into the relationship ...but the car repays in more than equal measure.
As for engine beauty......
Jaguar has found their way, lost it, and found it again at various times over the years. The fuel injected v12s are indeed a nightmare of hoses clumped on top but when everything is sorted and cleaned even they're a bit awe inspiring in their own way.
Tastes vary, of course, but pesonally I don't go for the brightly painted/adorned V12s. Or any other engine, for that matter. I prefer a more business-like appearance. Clean, orderly, perhaps a few bits of lightly polished aluminum. The earlier Jag motors you mentioned have it. Handsome, not glitzy.
Yellow and red paint, and brightly colored plug wires, and chrome goodies.....it all screams "Rod and Custom" or "Hot Rod" to me. It just isn't Jaguar-ish IMHO.
Cheers
DD
#66
02-01-2014, 03:13 PM
Veteran Member
It is all very much a "horses for courses" sort of thing.
The XJS in either guise is a wonderful car, quiet, luxurious, smooth riding and elegant. Both the V12 and AJ6/16 engines are terrific and, when properly maintained, very reliable. With any car that is 2-3 decades of age, owner involvement in maintenance (or deep pockets) is a must but as others have said, it's all part of the fun.
The OP appears to be looking for performance? Now that can mean a lot of different things to different people. Certainly you can convert ANY car into a dragster and do burnouts if that's your thing, it all depends what you're looking for
For me, performance is about agility and quickness in daily use rather than top speed or qtr mile times that you can rarely experience. I love pushing my car in the twisty bits of the mountains, balancing the car in the turns using the throttle and then also cruising at 80mph on the highway in the lap of luxury. For me that ability is what makes the AJ6 with manual transmission the best combination, though I'm sure the 6L/4sp would be a close competitor.
In daily use the 5.3L/3spd/2.88 diff combo is lethargic. Yes it is smooth and acceleration has that rubber band seamless elasticity feeling but the gear ratios make it slow off the line and the 400 tranny is hardly spritely in gear changes. I did some quick calculations that perhaps illustrate this point of view a little better.
For 5.3L/3spd/2.88 diff/235/60/15 tyre
1st gear = 10.7mph per 1,000rpm
2nd gear = 17.8mph per 1,000rpm
3rd gear = 26.7mph per 1,000rpm
For 4.0L/5spd/3.54 diff/225/55/16 tyre
1st gear = 6.1mph per 1,000rpm
2nd gear = 10.6mph per 1,000rpm
3rd gear = 15.5mph per 1,000rpm
4th gear = 21.6mph per 1,000rpm
5th gear = 29.6mph per 1,000rpm
As you can see taking off in the stock V12 is akin to taking off in 2nd gear in the AJ6 manual. That's asking a lot of from the relatively small torque gain in the V12 (max 306lb/ft vs 278lb/ft). Also the wide spacing of gear ratios in the 3spd creates "dead spots" when calling for passing power at certain speeds. So yes the 5.3L is a marvel when accelerating from 120-140mph but a bit of a granny when a bit more oomph is called for at 40-50mph. I know which I would prefer and having been to the beautiful islands of New Zealand, I reckon the same would apply
Initial acceleration is just part of the performance equation though, suspension setup, weight and wheel/tyre combination have a significant effect too. Again to my way of thinking the manual AJ6 car trumps the V12 in this regard. How so?
All 5spd XJS's came standard from the factory with the "Sportspack" setup. This includes significantly uprated springs and dampers (43% stiffer springs up front), larger wheels (16") with lower profile tyres (55Zr's), thicker anti-roll bar, reduced power steering assistance (for better feel). The Sportspack option was available for V12's in certain years but few were sold that way as it just did not match the rest of the drivetrain or the car's mission.
Add those factors to the extra 200-250lbs sitting over the front axle and the 15" 70 aspect ratio wheel/tyre combo of the V12 and you will have a car that wants to push the nose in a corner and roll over the gyres. Not great for sporty handling IMHO.
Of course you can make mods to either car to make them faster/handle better. But to me it's clear which car Jaguar intended to be the sportier of the two. Your mileage may vary
Here is a contemporary review of the 5spd and I think the reviewer pretty much nails it.
1994*Jaguar*XJS Review By Richard Truett
The XJS in either guise is a wonderful car, quiet, luxurious, smooth riding and elegant. Both the V12 and AJ6/16 engines are terrific and, when properly maintained, very reliable. With any car that is 2-3 decades of age, owner involvement in maintenance (or deep pockets) is a must but as others have said, it's all part of the fun.
The OP appears to be looking for performance? Now that can mean a lot of different things to different people. Certainly you can convert ANY car into a dragster and do burnouts if that's your thing, it all depends what you're looking for
For me, performance is about agility and quickness in daily use rather than top speed or qtr mile times that you can rarely experience. I love pushing my car in the twisty bits of the mountains, balancing the car in the turns using the throttle and then also cruising at 80mph on the highway in the lap of luxury. For me that ability is what makes the AJ6 with manual transmission the best combination, though I'm sure the 6L/4sp would be a close competitor.
In daily use the 5.3L/3spd/2.88 diff combo is lethargic. Yes it is smooth and acceleration has that rubber band seamless elasticity feeling but the gear ratios make it slow off the line and the 400 tranny is hardly spritely in gear changes. I did some quick calculations that perhaps illustrate this point of view a little better.
For 5.3L/3spd/2.88 diff/235/60/15 tyre
1st gear = 10.7mph per 1,000rpm
2nd gear = 17.8mph per 1,000rpm
3rd gear = 26.7mph per 1,000rpm
For 4.0L/5spd/3.54 diff/225/55/16 tyre
1st gear = 6.1mph per 1,000rpm
2nd gear = 10.6mph per 1,000rpm
3rd gear = 15.5mph per 1,000rpm
4th gear = 21.6mph per 1,000rpm
5th gear = 29.6mph per 1,000rpm
As you can see taking off in the stock V12 is akin to taking off in 2nd gear in the AJ6 manual. That's asking a lot of from the relatively small torque gain in the V12 (max 306lb/ft vs 278lb/ft). Also the wide spacing of gear ratios in the 3spd creates "dead spots" when calling for passing power at certain speeds. So yes the 5.3L is a marvel when accelerating from 120-140mph but a bit of a granny when a bit more oomph is called for at 40-50mph. I know which I would prefer and having been to the beautiful islands of New Zealand, I reckon the same would apply
Initial acceleration is just part of the performance equation though, suspension setup, weight and wheel/tyre combination have a significant effect too. Again to my way of thinking the manual AJ6 car trumps the V12 in this regard. How so?
All 5spd XJS's came standard from the factory with the "Sportspack" setup. This includes significantly uprated springs and dampers (43% stiffer springs up front), larger wheels (16") with lower profile tyres (55Zr's), thicker anti-roll bar, reduced power steering assistance (for better feel). The Sportspack option was available for V12's in certain years but few were sold that way as it just did not match the rest of the drivetrain or the car's mission.
Add those factors to the extra 200-250lbs sitting over the front axle and the 15" 70 aspect ratio wheel/tyre combo of the V12 and you will have a car that wants to push the nose in a corner and roll over the gyres. Not great for sporty handling IMHO.
Of course you can make mods to either car to make them faster/handle better. But to me it's clear which car Jaguar intended to be the sportier of the two. Your mileage may vary
Here is a contemporary review of the 5spd and I think the reviewer pretty much nails it.
1994*Jaguar*XJS Review By Richard Truett
"The 24-valve straight-six engine in the XJS convertible idles so smoothly that you would swear it isn't running at all. Lexus has nothing on Jaguar in this area":
Man, where would this statement put V12 owners' claim of being smoother than the straight six? If this guy didn't hear anything at all, then nothing can be possibly quieter, including Jag's V12. However, I don't think I can make such claim, myself; when my six is running in my garage I can hear it running, perhaps because other than the car, the place is super quiet. Of course, including no less than Lexus in the same sentence sure adds validity to it; Lexus' ARE fastidiously smooth and quiet.
#67
02-01-2014, 06:09 PM
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#68
02-01-2014, 06:52 PM
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The AJ16 was there... the supercharger was there... the mating tranny was there... why in the world didn't Jaguar take advantage of the opportunity to score big... very big by putting the XJR6' running gear on the glorious XJS? And yes, along with that great "J" gate and that more complete instrument cluster? It was ALL THERE, ready to put it on the car and 21 HP better than the V12 and I'm sure better mpg.
I know, the XK8 was waiting in the wings, but so was the XJ8, as the X300 running gear changes from the XJ40 were good for only '95, '96 and '97. The XJS equivalent changes -including the supercharger- would've been for '95 and '96 (with no V12 in '96), only two years, yes, but would've been spectacular XJS years.
So, your XJR6 is very special, too, just about 1.0 whole second faster (0 to 60) than the larger power plant, more expensive and worse mpg XJ12.
So much more fun... I'd keep that baby...
OK, that'll be enough...
Cheers,
#69
02-01-2014, 06:59 PM
Veteran Member
Cheers
#70
02-01-2014, 09:16 PM
Veteran Member
I am on my 6th XJS. Still sorting it out. It is a 89 Marelli convertible. I bought it as a non-running low mileage car. I, like Doug, have a high school diploma. I bought my first XJS back in about 85. It was a 79. A nightmare of a car until I was informed of the wonders of dielectric compound on all of the multi-pin connectors under the hood. After that, believe it or not, the car performed flawlessly until someone offered me more than I had in it at a car show. I then had a 89 convertible with Lucas ignition, a 85 coupe that was about as good, a 86 coupe, a 95 6.0 convertible, and now a 89 Marelli car. All of them were V-12s. I've never owned a 4.0, as it just never appealed to me. I have a 4.0 in my Jeep. Bulletproof. But the enjoyment of ownership is in its reliability, not its appeal of design.
I feel that to take any of my Jags to a shop for repair is to admit defeat. I do have a place to work on my cars, and that is a must with a Jag I feel.
I can only add....do your homework. Buy a workshop manual. Don't allow yourself to get in a position of "need" to count on the car. They are reliable, once they are sorted out. A limp around Jag will cost a bundle in tow bills. I have never had a XJS towed anywhere. My V-12 XKE did have to be...once.
Anyway, I find the appeal of the V-12 to be in the enjoyment of facing a challenge. As the old saying goes, "if it were easy, old women and children would do it". If mechanical things challenge you, buy the 6 cylinder. If raising the hood, and seeing that V-12, and being glad you own it, (even when it doesn't act just right), keeps your automotive fire burning, DIVE IN!!! Its just a sum of parts. My grandfather taught me the KISS analysis very early on. If another man designed it, figure out what made it work, and you can fix it he would say.
I will close with this. The car I currently am sorting out took me about 40 hours to figure out how to even get it to run. But systematically, I went item by item, figuring out what made what work, and only having basic tools, figured out that somehow the flywheel speed sensor was wired in backwards. Maybe 150.00 was spent, not counting my time. What I really love about these cars, is that if you look long enough, be careful, you will find a "don't wanter" who will sell the car a relative bargain. But remember, the cheapest thing you can ever do to a Jag is buy it.
I feel that to take any of my Jags to a shop for repair is to admit defeat. I do have a place to work on my cars, and that is a must with a Jag I feel.
I can only add....do your homework. Buy a workshop manual. Don't allow yourself to get in a position of "need" to count on the car. They are reliable, once they are sorted out. A limp around Jag will cost a bundle in tow bills. I have never had a XJS towed anywhere. My V-12 XKE did have to be...once.
Anyway, I find the appeal of the V-12 to be in the enjoyment of facing a challenge. As the old saying goes, "if it were easy, old women and children would do it". If mechanical things challenge you, buy the 6 cylinder. If raising the hood, and seeing that V-12, and being glad you own it, (even when it doesn't act just right), keeps your automotive fire burning, DIVE IN!!! Its just a sum of parts. My grandfather taught me the KISS analysis very early on. If another man designed it, figure out what made it work, and you can fix it he would say.
I will close with this. The car I currently am sorting out took me about 40 hours to figure out how to even get it to run. But systematically, I went item by item, figuring out what made what work, and only having basic tools, figured out that somehow the flywheel speed sensor was wired in backwards. Maybe 150.00 was spent, not counting my time. What I really love about these cars, is that if you look long enough, be careful, you will find a "don't wanter" who will sell the car a relative bargain. But remember, the cheapest thing you can ever do to a Jag is buy it.
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LuvmyXJS' (02-02-2014)
#71
02-01-2014, 11:52 PM
I was having a conversation with a co-worker saying there is just something appealing about the V12. Another co-worker chimed in and said "Joe you don't need a V12" and I spoke back "Nobody NEEDS a V12, it's about want"
I have a 94 XJ40 with the 4.0 and it has been an awesome commuter car these last few years. The 6 is super smooth and is so smooth you can hardly tell it's running.
Funny story.... I was slowing down for a stop after leaving the freeway and the car stalled at the bottom of the ramp. I initially didn't notice until it failed to move when I pressed the gas. I then Looked at the gauges and saw the car had stalled. That's smooth.
That being said the engine is fairly easy to work on. Even when I had to replace the hoses under the intake it wasn't that big of a deal. Just a little more time consuming. The 12 on the other hand looks very imposing and I've worked on a lot of cars in the last almost 30 years as a professional mechanic. From old Beetles and Army Jeeps with flat and straight 4s, flathead I6s to twin turbocharged Volvos and Supercharged Mercedes Benz and V8 BMWs. They all come apart one bolt at a time though some bolts are harder to get to.
Consequently I have a pretty good supply of curse words and phrases in my toolbox and since my Jaguar is not my only vehicle, and never could be I can afford it to not always be 100%. Not that it can't be reliable, just that I can afford to let it sit if I needs something.
As much as I like my XJ6 I'm really looking for a XJS V12 Coupe as my next car. My head says get the 6 but like Uncle Jack said in Breaking Bad "The heart wants what the heart wants" and mine wants a V12.
I have a 94 XJ40 with the 4.0 and it has been an awesome commuter car these last few years. The 6 is super smooth and is so smooth you can hardly tell it's running.
Funny story.... I was slowing down for a stop after leaving the freeway and the car stalled at the bottom of the ramp. I initially didn't notice until it failed to move when I pressed the gas. I then Looked at the gauges and saw the car had stalled. That's smooth.
That being said the engine is fairly easy to work on. Even when I had to replace the hoses under the intake it wasn't that big of a deal. Just a little more time consuming. The 12 on the other hand looks very imposing and I've worked on a lot of cars in the last almost 30 years as a professional mechanic. From old Beetles and Army Jeeps with flat and straight 4s, flathead I6s to twin turbocharged Volvos and Supercharged Mercedes Benz and V8 BMWs. They all come apart one bolt at a time though some bolts are harder to get to.
Consequently I have a pretty good supply of curse words and phrases in my toolbox and since my Jaguar is not my only vehicle, and never could be I can afford it to not always be 100%. Not that it can't be reliable, just that I can afford to let it sit if I needs something.
As much as I like my XJ6 I'm really looking for a XJS V12 Coupe as my next car. My head says get the 6 but like Uncle Jack said in Breaking Bad "The heart wants what the heart wants" and mine wants a V12.
Last edited by Jeh; 02-01-2014 at 11:55 PM.
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LuvmyXJS' (02-02-2014)
#72
02-02-2014, 01:08 AM
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If forced to give just one reason I'd say that it's simply time for a change. I've had it almost eight years. I'll be keeping for at least a few more months, though.
I'm looking forward to driving a Ser III again....the most modern of all antique automobiles...with a V12 this time, not the old 4.2 six. As great as the XJR/6 is it just lacks that Jaguar-ish feeling. And, truth is, owning it hasn't been a pleasure cruise the entire time. The engine management sytem has given me a fair bit of grief....something I never had to face on my older jags.
The AJ16 was there... the supercharger was there... the mating tranny was there... why in the world didn't Jaguar take advantage of the opportunity to score big... very big by putting the XJR6' running gear on the glorious XJS? And yes, along with that great "J" gate and that more complete instrument cluster?
A question we've all often asked. It woulda been great!
It was ALL THERE, ready to put it on the car and 21 HP better than the V12 and I'm sure better mpg.
Actually I don't think so. The XJR6s are not espeically gasoline frugal. The supercharged six eats almost as much gas as my old XJS V12. Maye 1.0 or 1.5 mpg better at highway speeds but just the same in town as the old V12. About 12-13 mpg
So, your XJR6 is very special, too, just about 1.0 whole second faster (0 to 60) than the larger power plant, more expensive and worse mpg XJ12.
According to period road tests the XJR6 was just a bit faster 0-60 and 1/4 mile than the X300 6.0 V12, and about the same as the XJS 6.0 V12.
It's wayyyyyy faster than an XJS with the old 5.3 V12, that's for sure....at least if the 5.3 is in bone-standard form. No comparison.
So much more fun... I'd keep that baby...
. Heck, it has almost no market value. It might be worth keeping just to have on hand.If it wasn't black (ughhh! Never again!) and in need of fresh paint, I might be more likely to keep it. Don't know if I could bear putting a cheapie paint job on a Jag and the $5000 needed for a good quality job is money I'd rather spend on my Ser III project.
Cheers
DD
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Forcedair1 (02-02-2014)
#73
02-02-2014, 11:01 AM
Life sure has a way of throwing us all curve ***** and lessons. Years ago I was on a trip in a large city when I saw a older gentleman putting gas in what appeared to be a 1989 or so red XJS convertible. I had not seen a XJS at all in my area for several years but this one was in what appeared to be in like concourse condition and man did it get my attention. The sheer beauty and elegance of that car stuck with me and even though I did not see another XJS in my area I could not get that car out of my mind.
Fast forward several years and I had decided I wanted to join a car club. Strange thing was I had not picked out the car yet so I started with a clean slate. As life goes we have all come into owning our current Jags for different reasons. I think some of us chose our cars and for some the cars chose us. At any rate as I went down the list of pros and cons of several different kinds of cars and the XJS for me kept coming out on top. Now, keep in mind I still did not know of an XJS in my area to look at in person, sit in or drive but from a list of features, purchase cost etc I found the XJS still was coming out on top of my want list.
So now came the big question; V12 or 6? Well for me living in a fairly remote area and with limited abilities under the hood ( my back ground is on the body side of vehicles with just enough knowledge on the mechanical to be dangerous), I decided I better get a 6. So I started focusing on the 6 and discovered that there really were not that many years the XJS was available with a 6 and as a convertible. Oh, yes and since I mentioned my back ground was not on the mechanical side I also thought if I could get one with out board rear brakes, OBD 2 scanner etc. that might be a good start for a novice like my self.
As I have stated before I have all the respect in the world for those that can tackle and maintain the 12. Not all of us have the abilities and patience to do so but my respect goes to those that do. For many of us the 6 gives us the opportunity to own and drive an XJS. Jaguar put themselves on the automotive map with the XK inline 6 and due to emission requirements in the early 1970's had to use a larger engine to get the power they needed with all the power robbing emission devices required at the time. The V12 was a good choice as the little piston chambers of the V12 allowed the engine to burn cleaner while still providing decent power and silky smoothness at the time. Just look at the power of the Corvette V8 through the mid to late 70's with most rated at around 170 HP and the V12 was a good engine at the time. But as time marched forward and technology progressed auto manufactures were able to get the power they needed with smaller power plants and pass required emissions.
What engine you choose to have in your XJS will come down to personal preference and abilities. The V12 was available for 20 years so there are many to choose from but for many like myself with limited mechanical abilities and or time etc. the fact is you have a viable choice. Jaguar offered a smooth and accessible option in the AJ6 and AJ16 six cylinder package. With the different rear axle gearing options and transmission options there is a XJS out there that will fit your needs, wants and abilities.
Fast forward several years and I had decided I wanted to join a car club. Strange thing was I had not picked out the car yet so I started with a clean slate. As life goes we have all come into owning our current Jags for different reasons. I think some of us chose our cars and for some the cars chose us. At any rate as I went down the list of pros and cons of several different kinds of cars and the XJS for me kept coming out on top. Now, keep in mind I still did not know of an XJS in my area to look at in person, sit in or drive but from a list of features, purchase cost etc I found the XJS still was coming out on top of my want list.
So now came the big question; V12 or 6? Well for me living in a fairly remote area and with limited abilities under the hood ( my back ground is on the body side of vehicles with just enough knowledge on the mechanical to be dangerous), I decided I better get a 6. So I started focusing on the 6 and discovered that there really were not that many years the XJS was available with a 6 and as a convertible. Oh, yes and since I mentioned my back ground was not on the mechanical side I also thought if I could get one with out board rear brakes, OBD 2 scanner etc. that might be a good start for a novice like my self.
As I have stated before I have all the respect in the world for those that can tackle and maintain the 12. Not all of us have the abilities and patience to do so but my respect goes to those that do. For many of us the 6 gives us the opportunity to own and drive an XJS. Jaguar put themselves on the automotive map with the XK inline 6 and due to emission requirements in the early 1970's had to use a larger engine to get the power they needed with all the power robbing emission devices required at the time. The V12 was a good choice as the little piston chambers of the V12 allowed the engine to burn cleaner while still providing decent power and silky smoothness at the time. Just look at the power of the Corvette V8 through the mid to late 70's with most rated at around 170 HP and the V12 was a good engine at the time. But as time marched forward and technology progressed auto manufactures were able to get the power they needed with smaller power plants and pass required emissions.
What engine you choose to have in your XJS will come down to personal preference and abilities. The V12 was available for 20 years so there are many to choose from but for many like myself with limited mechanical abilities and or time etc. the fact is you have a viable choice. Jaguar offered a smooth and accessible option in the AJ6 and AJ16 six cylinder package. With the different rear axle gearing options and transmission options there is a XJS out there that will fit your needs, wants and abilities.
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Forcedair1 (02-02-2014)
#74
02-02-2014, 11:18 PM
Veteran Member
It is kind of like with my XJS. Even if I did have the nitrous armed, as long as my foot behaves by not pushing the gas to the injection threshhold, no juice will be triggered, therefore no extra fuel will be used, at all. On either car, invoking forced air just once in a while for fun will still keep the overall gas mileage decent. I do realize that it is a little harder to achieve this in the s/c car than it is in the N20 car because, for some reason, the s/c comes in at a lesser acceleration point in the gas pedal travel compared to the nitrous injected XJS, which is set to start injection only when very close to WOT.
Needless to say, in the freeway and at fairly constant speed, the extra power of forced air is seldom needed, seldom used, other than to pass, and then what, 5-7 seconds? compared to the what, 20 minutes, or one hour for the entire drive? In reality, the percentage of time that forced air is actualy used is minimal.
This is why, IMO, a s/c car is preferable to a big a.. V8. Use more fuel only for the few seconds that you need it. The s/c 4.0L Jag, if forced, can keep up pretty close with a normally aspirated 6.0L V8, but the Jag will use extra fuel only when you force it, whereas the big V8 will tend to use more fuel almost all the time.
Cheers,
#75
02-02-2014, 11:33 PM
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
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While dragging the supercharger around and operating with about 2 full points less compression ratio! In non-boost conditions the XJR6 engine just isn't as efficient as the NA version, it seems. I've never been able to match the fuel economy of the normally aspirated cars. Not that I'm complaining, mind you !
Cheers
DD
#76
02-03-2014, 01:14 AM
I am getting off topic, but I agree.
I recently 'took over' my father's vintage car, a 1928 Alvis. He bought it for 60 pounds in 1960, aged 20, and spent 18 months restoring it. It was difficult - he had to save his shillings then buy postal orders from the NZ Post Office, then when he had enough, mail them to UK to pay for a car part. No internet credit card usage then..
As a kid, we did many miles in that car. It has only done about 1000 miles since 1980 however.
recently, now aged 74 with serious heart problems, he decided the car was better with me. I am doing a rolling, second-time-around refurbishment as problems come to light. The car is kept drivable. I keep him updated with phonecalls and emailed photos every time I do a little job - he gets much pleasure from this, without lying on his back in the garage sorting it out.
I pick his brains by phone. 54 years later he remembers everything about it. He lived and breathed that car for about 6 years, before he got married.
He visited this weekend, detouring 120 miles because he wanted to drive it now the steering box is rebuilt. I was havng some minor generator and fuel flow issues, and he remembers everything about it. It is, for me, a unique experience to see that memory in action, and him helping me solve these problems half a century later..
two Coventry cars, 95 X300, and 1928 Alvis 12/50
#77
02-14-2014, 12:29 AM
ud
[QUOTE=AL NZ;889873]at the risk of covering old ground, I am considering an XJS, and trying to decide between a 6 and a V12.
I figure that a good AJ16 or AJ6 4 litre will be lighter in the front for handling, yet reasonably easily tuned up to, say 260-280bhp with straight forward mods.
Others of you will have been through this process before. What are the opinions?
/QUOTE]
The V12 as a car is a complete dog.
The 6 cylinder XJS was faster from the factory and can be made to go round corners, which the huge and desperately overweight V12 is totally incapable of.
I have developed a handling and performance kit for the 6 cylinder and you can take a further 100kg easily off the weight.
You can 350bhp easily and it uses half the fuel of the V12.
Forget the V12 it's an out of date piece of rubbish with dreadful thermal efficiency, which destroyed all the development of the proper 6 cylinder car because they didn't want it to compete with the V12 for pure marketing BS.
I figure that a good AJ16 or AJ6 4 litre will be lighter in the front for handling, yet reasonably easily tuned up to, say 260-280bhp with straight forward mods.
Others of you will have been through this process before. What are the opinions?
/QUOTE]
The V12 as a car is a complete dog.
The 6 cylinder XJS was faster from the factory and can be made to go round corners, which the huge and desperately overweight V12 is totally incapable of.
I have developed a handling and performance kit for the 6 cylinder and you can take a further 100kg easily off the weight.
You can 350bhp easily and it uses half the fuel of the V12.
Forget the V12 it's an out of date piece of rubbish with dreadful thermal efficiency, which destroyed all the development of the proper 6 cylinder car because they didn't want it to compete with the V12 for pure marketing BS.
#78
02-14-2014, 09:47 AM
Wow, don't hold back, Tell us how you really feel. 
Im going to out on a limb but aside from say a Ferrari or Lambo the V12 cars of the era weren't meant to be track cars but more of a Grand tourer.
Personally I have a 6 in my car and while its a great engine, I want an XJS with a V12. Do I need a car with a V12? No not really but then again no one needs a car with a V12. Its about want.
Im going to out on a limb but aside from say a Ferrari or Lambo the V12 cars of the era weren't meant to be track cars but more of a Grand tourer.
Personally I have a 6 in my car and while its a great engine, I want an XJS with a V12. Do I need a car with a V12? No not really but then again no one needs a car with a V12. Its about want.
#79
02-14-2014, 11:25 AM
Veteran Member
#80
02-14-2014, 11:36 AM
Veteran Member
The 6 cylinder XJS was faster from the factory and can be made to go round corners, which the huge and desperately overweight V12 is totally incapable of.
Well my 6 cylinder was nothing like as fast as my V12.
I have developed a handling and performance kit for the 6 cylinder and you can take a further 100kg easily off the weight.
You can 350bhp easily and it uses half the fuel of the V12.
Now you're talking! tell us how, do, please!
Forget the V12 it's an out of date piece of rubbish with dreadful thermal efficiency, But so am I and many of us here! And you forget to say the other things a V12 is: The best Grand Touring car ever I have been in, supremely comfortable, utterly wonderful to sit behind at 90 mph with occasional forays into the italian autopstrada middle lane at 120 (everything on the outside lane was doing 150 when I was there last - I am quite serious), vibration free not like an engine at all, fun to fettle, glamourous, seductive, and not nearly as bad at corners as you imply. In short, if you want a few moments of utter wow in your life, preferably in my case with a wife you adore and took on honeymoon in it, the 6 just does not come close. I am talking Cary Grant and Doris day here, Faye and Steve, Julie and Warren. Real stars in real cars.
Well my 6 cylinder was nothing like as fast as my V12.
I have developed a handling and performance kit for the 6 cylinder and you can take a further 100kg easily off the weight.
You can 350bhp easily and it uses half the fuel of the V12.
Now you're talking! tell us how, do, please!
Forget the V12 it's an out of date piece of rubbish with dreadful thermal efficiency, But so am I and many of us here! And you forget to say the other things a V12 is: The best Grand Touring car ever I have been in, supremely comfortable, utterly wonderful to sit behind at 90 mph with occasional forays into the italian autopstrada middle lane at 120 (everything on the outside lane was doing 150 when I was there last - I am quite serious), vibration free not like an engine at all, fun to fettle, glamourous, seductive, and not nearly as bad at corners as you imply. In short, if you want a few moments of utter wow in your life, preferably in my case with a wife you adore and took on honeymoon in it, the 6 just does not come close. I am talking Cary Grant and Doris day here, Faye and Steve, Julie and Warren. Real stars in real cars.