XJ XJ8 / XJR ( X308 ) 1997 - 2003

Gearbox question, driving style

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Old 11-27-2012, 03:36 AM
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Default Gearbox question, driving style

Hi,
i have a few questions regarding the sport mode.

1) If i do not have sport mode selected, and press the gas pedal to the floor, it should accelerate as fast as in sport mode doing the same, right? Maybe reacting little slower but it should downshift, accelerate and keep the revs up until i have the pedal down, right?

2) i read the manual (i know, i know, but i am girl, and we girls read manuals already from pure joy of reading), but could not anywhere find reference if S mode somehow wears the gearbox (or anything else) faster. It sucks fuel faster for sure, but that i know.

3) do you use S mode in daily driving or just when you are on track or on some nice empty street enjoying the drive and sound?

Thank You for answers!
 
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Old 11-27-2012, 04:34 AM
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1. Exactly. In kick-down mode the car should accelerate as fast, as in S mode.
2. No. The S mode wears nothing at all. The transmissions just shifts up @ higher RPM (and i can feel that the accelerator pedal is more responsive in S mode).
3. I'm using the S mode for everyday driving, even during cold'n'snowy russian winters

P.S. What a nice and rare combo - a girl and an XJ Wish i could see you both
 
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Old 11-27-2012, 04:34 AM
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1) "Normal" mode should downshift when you floor it yes, this is normal for an automatic transmission. Shifts are a little gentler than in sport mode, and will typically happen at lower revs. In fact, Sport mode might even occasionally downshift two gears, if you've been trundling along gently and then suddenly mash it to the carpet.

2) It would surprise me if Sport mode wore out the transmission noticeably faster than "Normal" mode.

3) Completely up to yourself, depending on your humour. Some folk like the sharp-and-aggressive aspect of Sport mode, and leave it on all the time.
 
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Old 11-27-2012, 04:37 AM
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Actually there should be less wear in tranny @ S mode, since there's less slipping in clutches during shifts.
 
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Old 11-27-2012, 04:42 AM
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Originally Posted by MoscowLeaper
Actually there should be less wear in tranny @ S mode, since there's less slipping in clutches during shifts.
It's probably a little easier on the fluid couplling right enough, but it probably slaps the planetaries and little sprag-clutches around a little harder. Nothing that should make any difference, though.

EDIT: Oh, excuse me - I see what you mean now. Well, it's probably a case of exchanging one sort of abuse for another, and so evens itself out overall! ;o)
 

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Old 11-27-2012, 04:52 AM
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Originally Posted by jimgoose
It's probably a little easier on the fluid couplling right enough, but it probably slaps the planetaries and little sprag-clutches around a little harder. Nothing that should make any difference, though.

EDIT: Oh, excuse me - I see what you mean now. Well, it's probably a case of exchanging one sort of abuse for another, and so evens itself out overall! ;o)
The main reason for wearing the cluthces is slippage during shifts (that "comfortable" shifts), they are the weakest part of the tranny. It's pretty hard to damage the planetary gears with firmer shifts@higher RPMs.
When i was driving my Chevys (1979 caprice, 1991 caprice 9c1, 1996 caprice 9c1) i ALWAYS used the shift kits to get rid of hydraulic accumulators and that always caused a really HARD shifts, but the transmissions lived better, than without these kits.
 
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Old 11-27-2012, 05:00 AM
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Originally Posted by MoscowLeaper
The main reason for wearing the cluthces is slippage during shifts (that "comfortable" shifts), they are the weakest part of the tranny. It's pretty hard to damage the planetary gears with firmer shifts@higher RPMs.
When i was driving my Chevys (1979 caprice, 1991 caprice 9c1, 1996 caprice 9c1) i ALWAYS used the shift kits to get rid of hydraulic accumulators and that always caused a really HARD shifts, but the transmissions lived better, than without these kits.
Interesting. Good info.
 
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Old 11-27-2012, 05:33 AM
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FWIW (and irrelevant really since you've got the 5 speed box) I was surprised to find that the 6 speed box only uses first gear in S mode
 
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Old 11-27-2012, 05:34 AM
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Originally Posted by jimgoose
Interesting. Good info.
It's just like on a MT. You have a clutch, you can take-off real slow, holding the clutch, it's nice, but the life of the clutch is limited - it's overheating, lot's of wear, sometimes it even smells OR you can rev the engine a little operate the clutch pedal as usual - if your RPMs are not in the red zone - no damage to clutch at all, almost no wear, no heat, no smell
Apart the planetary gears and hydraulic circuits the AT is all the same - it's all about the clutches
 
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Old 11-27-2012, 05:39 AM
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Originally Posted by steveinfrance
FWIW (and irrelevant really since you've got the 5 speed box) I was surprised to find that the 6 speed box only uses first gear in S mode
The ZF 6hp, found on X100/X150/X350/X250/X351 uses the first gear in S mode or in a kick-down mode. BUT, talking about the X351, if you put the gear knob in a S mode, push down the dynamics mode button (to make an IC to show the active gear), you could see that the transmission is in a first gear. But the SDD shows that it is in second. In winter mode it ALWAYS starts from second gear.
 
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Old 11-27-2012, 05:45 AM
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Originally Posted by sandy85
i drive it like i stole it anyway averaging 14,9l/100km :-)
Lucky you
I'm averaging 19.2/100km @ 95RON gas or 17.1/100km @ 98RON gas. But it runs better on an 98
 
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Old 11-27-2012, 05:47 AM
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Originally Posted by MoscowLeaper
Lucky you
I'm averaging 19.2/100km @ 95RON gas or 17.1/100km @ 98RON gas. But it runs better on an 98
13.8l/100km here - but I cheat, because it's a manual! ;o)
 
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Old 11-27-2012, 05:49 AM
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Originally Posted by sandy85
hah, need few little tweaks, then will do and will have my profile pic updated soon
Sorry, but i have to do it


P.S. No offence
 
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Old 11-27-2012, 05:52 AM
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Originally Posted by steveinfrance
FWIW (and irrelevant really since you've got the 5 speed box) I was surprised to find that the 6 speed box only uses first gear in S mode
The Mercedes built 5 speed box on XJR (and XKR) also does this.
 
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Old 11-27-2012, 07:17 AM
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Originally Posted by MoscowLeaper
Lucky you
I'm averaging 19.2/100km @ 95RON gas or 17.1/100km @ 98RON gas. But it runs better on an 98
is there really that big difference between 95 and 98? It might not make up for the higher fuel price but...
Will try to fill it with some premium fuel next time and check it by my self!

And pic you see in avatar haha, that have to do now until i have some nice with my cat.
 
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Old 11-27-2012, 09:51 AM
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the Sport button basically tells your gear box to hold the gear a little longer....and modifies the pedal to be a little more sensative

example: Normal mode....if you have your pedal pressed at 75%..it will give you 75%......in sport mode...if you have your pedal pressed at 50%...it will give you something like 90% (i dont know the exact math, but you get the idea)

leaving the car in S mode does not introduce any extra wear on the car. I usually drive around in S mode 95% of the time....sometimes it gets jerky in traffic
 
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Old 11-27-2012, 10:10 AM
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I think my car is broken....averaging 12.3/100km in my XJR, and I don't hang around....must try harder....then again, no Autobahn's over here....
 
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Old 11-27-2012, 10:54 AM
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Originally Posted by sandy85
is there really that big difference between 95 and 98? It might not make up for the higher fuel price but...
Will try to fill it with some premium fuel next time and check it by my self!

And pic you see in avatar haha, that have to do now until i have some nice with my cat.
There's huge difference between 95 and 98 over here. The quality of 95 really sucks. On 98 i've get better milage and, despite the higher price of the 98, it costs me less money.
Anyway this engine requires at least 95, but, with such a CR (10.75:1), 98 suits better.

Hmmm... Nice pic, but... Wish it could be larger
 

Last edited by MoscowLeaper; 11-27-2012 at 10:57 AM.
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Old 11-27-2012, 11:08 AM
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My VDP is in the "S" mode all the time. Average MPG is 19,4 (city+freeway). I burn 91 here in CA, and I am not concerned about fuel consumption. A mile or two (even 10!) per gallon more, will not make ANY difference in my life.

What's up with changing avatars all the time Sandy?
 
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Old 11-27-2012, 11:24 AM
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Originally Posted by danielsand
and I am not concerned about fuel consumption. A mile or two (even 10!) per gallon more, will not make ANY difference in my life.

What's up with changing avatars all the time Sandy?
Life's too short to care about a fuel economy
 


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