I'm using the same tire pressure as you. The ride is a lot quieter but not softer, at least in the 2012. My 2012 S/C has a stiffer suspension than my 2009 S/C and is definitely stiffer than the base or portfolio version of the 2012

 

That's because the 2012 SC is an XFR for less. The original SC was a regular XF but with stiffer roll bars and dampers.

 

When I first got the car my12 NA portfolio.
Was getting about 12.0 l/100km on highway. (About 19mpg)
But now. Almost at 10k total milage and went on a road trip to Virginia and was getting around 9.0/ 100kms with the lowest being about 8.7. All highway. (About 27mpg)
I am still on snow tires so I don't know if it will get better. But I did notice on my other cars that it usually does get marginally better.
My point? I noticed a great improvement in fuel Econ when the engine broke in a bit.

 

a little update,

after the 5k Miles mark
My car now runs 12 mpg city

drove to my cousins, 24.5 miles away
Strictly going there and coming back uses up quarter tank. which looks about normal.

Again i have a 2012 Jag XF Supercharged

 

I agree that they stiffened the rear roll bar by 3 mm in the 2009 S/C, but I think the main difference is the dampening method used. The 2009 S/C had the older two-stage CATS system whereas the 2012 S/C and R have the continually-adjusting adaptive dynamic dampening system that I think makes the ride feel stiffer. Going over a minor washboard surface in the 2009 was no big deal, but going over the same surface with the 2012 tends to be somewhat annoying because of the vibration.

 

I thought the XFR had the whole shebang. Stiffer springs, roll bars and dampers.

Not sure about the continuously variable dampers though. I think the system is still an on/off two stage damper setup.

The only infinitely variable setup I know of is the Magna ride system with electronically controlled damping fluid viscosity. The other systems I know of use an on/off bleed valve or a two stage rotary electronically controlled damper switch which defaults to one setting when "off" and the other when "on". This may be controlled very frequently but it is still basically two stage damping.

Anyone know if the XFR uses continuously variable damper control? I mean, Porsche claims they do with PASM but I think they exaggerate.

 

According to the 2012 Jaguar brochure, both the XF S/C and XFR have continuously variable electronic damper control. Don't know if the 2010 and 2011 models have it.

 

I wonder what they mean by "variable".

"Continuously" variable isn't necessarily the same thing as "infinitely" variable.

Magna ride is infinitely as well as continuously variable as the dampers are continually responding to electrical inputs and the effect on damper rates is infinitely variable.

My understanding of all competing systems is they use two stage damping which may be responding continually to electrical inputs but the damping varies only from one fixed rate to a second fixed rate.

Who knows?

 

You and I have hijacked this thread over this suspension business so I will post one last communiqu'e on the subject in the form of a quote from the Jaguar brochure.

"ADAPTIVE DYNAMICS - Provides the optimum balance between low speed ride comfort and high speed handling precision, analyzing body movement, steering and road wheel inputs up to 500 times a second and continuously adjusting the suspension settings through electronically controlled dampers."

Sure sounds like variable damping to me. However, it is whatever it is.

 

My 2009 XF-SC gets about 20 mpg, but then, I'm no angel.

 

Yes, agreed it means variable and even continuously variable. However, does it mean variable in infinite gradations from softest to hardest damper rates or just switching from normal to firmer and back again? Big difference between those two types of adjustable suspension.

 

Unless you have it in Sport mode..that does suck a bit.

Mine gets normally at 75MPH with Cruise on; 28/29 MPG..in city I average real close to 18/19 MPG..my tires are nitrogen filled at 38 PSI..Very happy with it.

 

latest update;
this is a list of the mpg i've gotten on consecutive tanks. i attribute the range to my driving pattern (obviously). my daily commute is 4 miles. i have taken roadtrips to monterey and vegas though, where i scored the much higher readings. and as an aside i'm still only at a top speed of 120 mph so far, very briefly....
14.54
21.99
18.52
19.53
17.41
13.58
14.79
14.05
18.98
17.25
16.97
13.52
22.2
21.91
20.06
22.64
24.05
20.1
17.57

 

I wouldn't call my car broken in yet, but I've been averaging ~19-21mpg and my average speed is usually around 35mph, I did notice that the computer is usually over estimating the actual economy by ~1mpg, I'd rather it be conservative.

 

I average in the mid 17s on a 2011 Xf SC.

 

Just purchased my 2011 XF Premium with 27k, but my 600 mile trip home averaged 24.5 MPG. So far in-town only driving, I'm seeing 17-18mpg, but I haven't been through a full tank yet to get an accurate number.

 

My mileage in the brief time I've had my XFR, even with showing off to others since it's new to me, tends to average out to around 14-18 mpg. What was strange to me is I had a dealer loaner with the NA 5.0 and I only averaged 13.5 for the 70 or so miles I drove it. Some of it was hard driving trying to figure out how much less powerful it was without the SC, but there was a good stretch of highway thrown in there as well. Didn't see the mpg penalty for the extra 125 hp.

 

I have been very impressed with my gas mileage. There is probably a ton that factors in such as elevation, winter vs summer blend, how one drives, do you use your momentum around corners and come to full stops, etc. etc...


But my gas mileage has been excellent. I've been using 91 Octane fuel and basically switching every other tank between 7/11 gas and Chevron gas. I have been getting up to 18mpg city, and up over 30mpg highway! Yes I have the 5.0! I am loving this!


I live in SLC which is 4,200 feet above sea level. Summer blends in gas stations right now.

 

I forgot to mention in my post my "up to 30mpg" thing I said was with me going 75 as well. I also am about 18-19 city. Very happy with my gas mileage since my former car was a Pontiac G8 with a 3.6 L V6 in it and was getting about 12mpg city and 27mpg highway...so my gas mileage has improved with going to a 5.0....love it.

 

I just picked up a 2012 XFR from Dallas this weekend and drove it back to San Diego. The trip was 1380 miles in length. I set the cruise control to 68 - 70 mph for a little more than half the trip and got 25.8 mpg. (Observation - used 93 octane throughout Texas). On the back half of the trip I increase my speed to 75 - 78 mph and got 22.8 mpg (Used 91/92 octane in Arizona/CA). Combined for the 1380 miles was 24.6 mpg. This is very promising considering the official mileage for the 6-speed XFR is 21 mpg.