Looking for some advice here. While finishing up a contracting tour in Afghanistan, I've been searching for the right XJ-L. I've narrowed my search down to a 2012 Supercharged with 57,000 miles and a 2012 non-blown Portfolio with around 33,000 miles. The Super is a bit less expensive. Both have good maintenance records and haven't had any major repairs or recurring issues that I can tell. All other things being equal, I'd probably opt for the Super but wonder what I'm in for down the road in terms of reliability and longevity. We plan to keep it for some time and run it out well beyond 100K miles.. Do you think that supercharger adds much complexity and risk of serious issues with the 5.0 engine later in life?


Thank You


Tim

 

Supercharged 5.0 engine was/is widely used in other models and they are mostly trouble-free engines. However, due to direct injection they are very sensitive to dirty/old oil, so proper maintenance is more important than ever before.

 

Mplstim, I look at it this way: the supercharged engine is going to put more stress on the components at all times when compared to the same motor in the naturally aspirated form. I don't think anyone can argue that. With that being said, because everything is under more stress at all times, this means things are pushed harder and are closer to their breaking points at all times. Does this mean that after 50K miles the motor is going to give up the ghost and leave you stranded? By no means. Will you get 300K+ miles out of the engine? Possible, but this is where the difference comes. The naturally aspirated motor should make that mileage pretty easy where the supercharged motor is going to be fighting to get up to that mileage. So, getting the supercharged vehicle past 100K miles, no problem. Out to 200K miles, should be doable. Beyond that, I think you are going to find that this is the breaking point and where things will start to show a difference.

In the way of complexity, yes, there is more that can go wrong, but it is really a fairly simple setup with not that many more parts to go wrong. I would not worry about that.

 

Tim,

+1 on what Thermo said.

Jaguar offers multiple models and engines for almost every type of driver. The answer to your question depends on what type of driver you are and what floats your boat. If your primary concerns are reliability, longevity, and cost, then I suggest you look elsewhere and go with a vehicle with the fewest moving parts, such as a 4 cylinder engine or electric motor. Everything mechanical wears and can break down, and parts for luxury cars are expensive. If you have to ask how much it costs to maintain and repair, then you probably can't afford it.

The naturally-aspirated 5.0L engines has more than enough power for normal, everyday driving. So why did I buy the SC with 470HP? It's a blast to drive! The only way for you to know which engine is right for you is to drive both of them.

For me, the fun factor made my decision easy. Sure, 470HP is overkill, but I wouldn't have it any other way.

However, I'm in Atlanta and you're in Minnesota. If I was in Minnesota, I'd be driving an AWD XJ with a supercharged V6 - unless I spent winters in Florida.

Life is short, and you only go around once so enjoy the ride - with whatever engine you choose. I've been very pleased with my XJ and hope you make a good choice and enjoy yours as much as I enjoy mine.

Stuart

 

Stuart, thanks for the reply. I go back to my first Jaguar, a very nice 2002 XK8 that had the normally aspirated 4.0. The engine was great and I thought it to be perfectly fine for the car until.... a friend let me drive his 2004 XKR. The supercharger changed everything... the difference in low-end torque, the response to the throttle along with the deeper roarty engine sounds were intoxicating... I'm not planning to be constantly doing burn outs with it, just occasional sprints and "spirited" driving on winding country roads. I feel like I'm answering my own question here.. It's obvious I should go for the Super and avoid living with "I should have..."


As for winter driving, I wouldn't drive the Jag in deep snow anyway, we have a 4x4 truck for that. On plowed roads there's no problem with today's rear-wheel drive traction control. I had a RWD Chrysler 300 that never had issues on slick or snow-packed roads.. The Super might have an advantage over the standard with the better differential..

 

I am a new 2014 XJR owner.
Are you sure you want one with no warranty?

This is my first XJ and it's a very expensive and complicated car. So the extra 2 year CPO warranty on mine was worth the couple of thousand extra I think I paid.

I am a DIY guy but even getting a service manual for this car is a MAJOR problem. Still trying to find one and it appears TOPIX is the only game in town and it's expensive and very time consuming to attempt to download the 1300 page manual in small sections.
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I'm looking into an aftermarket service contract as part of the deal...

 

This is faulty logic. Supercharged cars are not inherently less reliable. Sure, there is one more thing to break - supercharger. Putting more power through components designed to handle that is not going to reduce their life. Sure, if you exceed design tolerances you will suffer premature failures, but this is clearly not the case here.

 

Unless you are pushing the car all the time the fact that the car has a supercharger should not affect the reliability of the car. Once you are up to speed the engine will only need to produce the same amount of power to move the car as a NA engine.

 

With supercharged cars, there are additional loads put on the car that a naturally aspirated car does not have. Specifically it is the load from the supercharger. I will admit that the load is relatively small (a few horsepower nominally), but it is just that much more power that the car has to make with each revolution. Not to mention that when you do apply power, you are going to apply more stresses to the engine components. I don't know many people that buy the supercharged cars just to putt-putt up to the grocery store and back. That is why I say that the engines do not tend to last as long.

 

If you take, say a naturally aspirated engine, then apply lots of boost to it - you will end up blowing it up sooner rather than later. This is not the same as taking an engine designed to take boost and applying within-design-tolerance levels of boost.

That is, AJ-V8 was designed to take boost and each component was engineered to make sure it can do so reliably.

You are confusing various concepts. First, "apply more stresses" should read "apply more boost" when talking about supercharger. While there is a mechanical concept of stress and strain, it isn't directly applicable here. That is, if you somehow to remove remove fuel from the equation, you are not going to deform engine components by applying maximum level of boost produced by any automotive supercharger.

The common mode of failure is called overboost. You pump too much air, fuel delivery system can't handle it and produces lean condition, or compresses too much and produces preigntion. Both produces fuel detonation at the wrong time. This mechanically breaks the engine, but it is fuel detonation and not the boost that produces force related to mechanical failure.

So how do you avoid overbootst? You design the system around boost, specifically your cooling system and your ECU are capable of managing supercharger. For a car that comes out factory with supercharger, both are true.

Second, you are trying to bring in abuse into discussion. Both naturally aspirated and supercharged engines are equally prone to it. Plus, abuse with XJ would be challenging. I don't expect owners doing standing burnouts with XJ, boosted or not.

 

Second, you are trying to bring in abuse into discussion. Both naturally aspirated and supercharged engines are equally prone to it. Plus, abuse with XJ would be challenging. I don't expect owners doing standing burnouts with XJ, boosted or not.


Oh Crap! I can't use my 550HP for fun?
New to all this power but I will have to do this at LEAST once!

I figured it would give an amazing smoke show with TracDSC or DSC off.
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Thanks for all the input gents! I'm thinking that Jaguar designed the engine to handle the stress of the supercharger boost and I'm not too worried about that. We are coming out of a nightmare scenario with our suddenly falling apart BMW 335xi. It was a great car but it passed 140k miles, despite careful maintenance over the past 3 years that we've owned it, all kinds of expensive things within the engine started to fail and the turbocharger would need to be replaced soon - all adding up to $10-12K of repairs. The mechanics at BMW are saying it's not worth it to dump all that money into a car that's only worth about $5000 and to cut our losses. A second opinion from an independent shop confirmed that. The shop owner says that the modern BMWs are becoming worthless beyond 100K miles.. I'll never go back to those cars again.

 

Mplstim, I owned many BMWs are they are expensive in the old age. One of the best ways to contain costs is to not service at the dealership (aka ***********). These days BMWs are common enough that you can find competent independent mechanic that could service your BMW without bilking you. Your $10K repairs at the dealership could easily translate to $4-5K at indy. However, at 140K miles your BMW will keep failing.

However, I am not sure used XJ would necessary be any different. If you want low mainteance car, used Jaguar should not be top of your list. For reliability -if you can handle boring, look at Lexus; if you can handle old geezer image, look at Buick. These top reliability charts.

 

Funny, "s t e a l e r s h i p" is censored.

 

Three rules of Jaguar (well, all cars) ownership :

1) Don't drive it broken. If it's overheating, making weird noises, got no power, stop immediately. Tow the car to a place of repair.

2) Always drive gently until the engine is thoroughly warm. Very gently for the first mile. Low revs, light throttle opening. No rapid acceleration until 10 minutes after the temp. gauge reads N. Oil takes a lot longer to warm up than coolant. My A6 2.7T had an oil temp gauge, it took ages to warm up.

3) Put the best oil in it, frequently.

 

Ditto! I live in Michigan and I do drive a XJL AWD Supercharged V6

 

It was my understanding that the supercharged engines have different internal specs to cope with the extra stress. That being said, I LOVE my car and I'm so glad every day that I didn't go for the naturally aspirated.

 

Here's a Dropbox link to the service manuals I have:
https://www.dropbox.com/sh/9swxmoxio...KYCt6eSUa?dl=0

Its a bit difficult finding what you need and the instructions aren't the best but it gets the job done. There's a lot of good info in there.

EDIT: Oops, I just realised this thread is old.

 

I've driven both and Supercharged is the way to go.

The power plus relative lightness of the big car is special. Not quite Mercedes V12 special, but the closest that I have felt.