I've driven half a dozen or so 2009 XF SC's now. I've encountered several that seemed sluggish.

I can imagine some of the lower end used car lots putting regular gas, might be the problem. Could also be the "learning" system has learned the driving style of a Sunday Sally, and may just need to be reset. But these are just guesses.

Any comments on what I might be encountering, and what the ramifications are for a potential buyer?

 

km get backed up often these days , especialy high end leases

 

I have experienced the same. Every supercharged jaguar i have driven, disappointed me. For some reason they are all beat up.

 

Any chance they were in winter mode?

 

"km get backed up" - I don't know what's a km.

Winter mode? I don't think so. If there's a dash indicator for this mode, then no. But in the sunlight, it's possible i might have overlooked the switch light.

 

Even though I am a power hungry person, I feel my 09 XF S/C is very spunky. Of course I do realize when I need to get some thrills I will drive my E63 or my Supra.
The Xf only has 420hp so I dont expect it to be a powerhouse. And I think what most of you are noticing is how the ECU tune is effecting the experience. I finally went for a ride in a 09 and a 11 XF S/C that had a tune in it with no pulley and that sure woke it up big time! Jag tunes the car for smooth drivability and in the eyes of 1 of us that appears like it is a slug. I just wish the tunes were not so rapingly expensive.
$1K-1200 would be fair but 1600-2K is too much for a pre-loaded tune.

On another note. I put my 09 in sport mode/DSC Off and manual shift to see how different it behaved. Well, soon as I click 2nd gear it spins wheels and 3rd I can get a chirp out of it.Pretty strong in my eyes for a luxury car that is de-tuned and stock.
This is just my 2 cents. Maybe some of these are beat up out there. Maybe mine is 1 of those that perform at the top of the bunch? There is always a few of them that seem to be stronger/faster of the group. I always use premium Shell gas and constantly perform maintience on my XF. I even clean the air filters and intake monthly.

Does anyone know if Jag has "Adaptive Learning" Like my AMG does? If so then that will explain it all. If I drive my AMG easy it will learn that and then when I go to drive it hard it feels so laggy and weak. Reset your ECU and see if it wakes it up a bit.

I Plan to put my 09 up for sale shortly so I can get a 10+ 5.0 or XFR so I can add a tune/ pulley. I want a 5.0 version so bad I will sell mine cheap so I can make this happen sooner. Maybe I will list it this week and go find me that XFR I want so bad. The wife is gonna freak but what else is new.

 

ZF transmission is adaptive. Regular gas would sap power big time under boost. "km backed up" is an allegation that odometers are tampered with to show lower mileage than actual, a serious criminal offence in Canada akin to auto theft but hard to catch and harder to prove. A "km" is a kilometer. Montreal poster would be familiar with km as Canada is a metric country. So is the UK but they still measure distance in miles like the US. Those are the only two countries that do as far as I know.

 

I did find one car that was reported at auction with about 21000 miles, but "true mileage unknown."
The seller has had it serviced, and now they claim over 50,000 miles.

I thought it should be difficult to tamper with mileage these days. Or is it just software?

 

The reason I suggested verifying if winter mode was on, is because I test drove a non-supercharged (385 horse) and it seemed like it didn't pickup as expected when you hit the gas. Found out it was in wintermode. When switched to normal drive, became spirited as you would expect. Hard to believe this would happen by chance in more than one test car though.

 

Good thought, though. I'll definitely check it if I encounter another lackluster drive.

 

theyre adaptive,(all are) and the harder the driver the harder the adaptations. put them in track mode. or normal. winter reduces throttle and power applications accordingly for more traction and control (obviously)
Some of the fastest stock cars Ive driven are driven by owners that replace rear tires more often
Watch how poor brakes become when you brake like a girl. they glaze, they squeel, they have terrible soft pedal feel, and increased stopping distance.
the trans and engine ecu and abs(traction) do adapt.
And then theres always a turd or two in the bunch for various reasons

 

I have both a supercharged and non-supercharged 4.2 car. The non-supercharged is more responsive at light throttle, the supercharged takes some wind-up and then goes much harder at higher rpm. The difference may be the 11.0-1 compression on the NA car and the 9.0-1 on the supercharged, it just takes some rpm to get it stepping out. Thsi makes the NA car nicer to drive aorund town, but the R is more fun in the country.

 

Brutal, with the cars adapting how you drive, is there a main fuse you can pull to reset the systems? On my saab if I pull fuse (i think # 17)it will reset the ecu and relearn its a/f mixs and make far more power. In my normal driving I drive fairly easy and not hard on my vehicles. So they adapt to easy driving, but every once in a while I enjoy spirited driving. But like the op says they can feel sluggish. I always use 93 in my cars and take care of them.

 

The following procedure is for resetting the transmission, which forces it to learn your driving style. I don't know if this would work on the XF, but it has worked on many Mercedes Benz models and it has worked in my Lincoln, as i have done it few times.


1. Turn ignition to ON. I don't know if this will be Accessories or full on RUN (without starting) position. It seems to vary.

2. Step on Accelerator Pedal and push it to the floor for 5 seconds

3. Turn ignition to OFF, leave key inserted

4. Release accelerator pedal

Don't do anything for at least 2 minutes. Don't open doors, windows, don't play with any electronics (though, I wouldn't think changing radio stations would affect it).

 

^ That sounds like the sneaky ECU reset I do on my E63 ?

 

BigCat, it most likely is. I don't know what other cars this formula works on, but Mercedez is one of them.

I have reset the tranny in my car three times within the last 12 months. It makes a huge difference.