I'm pretty much sold on the new XF. I'd never thought I'd own a Jag, but this car will be the perfect replacement for my Lexus GS 400 with 220,000 Miles on it.

My current GS is very similar to the XF in that it is rear wheel drive and has a 4 liter over head cam V8 with variable valve timing. My lexus gets 24-25 highway and since I drive mostly highway I get a combined 23 mpg which is ok for me even with $4 gas.

My first question is, what type of highway mileage have new owners been getting with either the normally aspirated or supercharged version. The reviews that I have been reading seem to indicate the mileage of the supercharged version is way below the EPA rating of 23. For the supercharged car, USA today averaged 13.6 in mixed hwy/city driving, and Motortrend averaged 14.8 mpg during their tests(they did not say hwy or city).

My second question is I am looking to get a sense for what the longevity of the supercharged jag engine has. I test drove the supercharged and the car is a blast, but I am concerned that any Forced Induction engine will not last as long as a normally aspirated engine. What is the longevity I should expect on a supercharged engine if run 90% hwy miles? My current Lexus has 220,000 miles on it and does not burn any oil. I change my oil with Mobile 1 every 3-5000 miles. If I could expect the engine to last 150,000 to 200,000 miles I would go for the supercharged car, if not, I'll go with the standard engine.

Thanks for your input

 

You don't but a Jaguar for her awesome fuel economy that's fact and I agree . Well, on the other hand related to the supercharged engine lifespan , XJR's engine requires some special maintenance at the certain mileages to the best knowledge of me considering XFR comes with the supercharger ,it might require similar attention though XJR and XFR are totally different beasts .

 

The current XF and XK as well as the corresponding XF SV8 and the current XKR have the sameengine, transmission and suspension, except for spring and damper rates. The expected XFR and the new XKR with the uprated 5.0 will similarly sharethese components. Jaguar only makes the two V8 engines and both the 4.2 and the 5.0 are or will be available in normally aspirated and supercharged versions.The brakes are probably very similar and the wheels fit either car. The body is different, duh.

I get fuel economy as good as 8 l/100 km on the highway at 120 km/hr which is outstanding for a 4,000 lb 4.2 liter automatic car. This is 35 mpg Imperial or about 28 mpg US. I get around 16 l/100 km around town, sometimes better, which is around 17 mpg Imp and around 13.5 mpg US. I have only 5,500 miles (8800km) on the car and mileage is steadily improving as the engine continues to loosen up.

The performance of the normally aspirated XF is sufficiently good to make the SV8 version overkill IMHO. 0-60 takes around 6 seconds as compared to around 5 secnds for the SV8 version. In the real World a 0-60 of 6 seconds is ample.

 

At this point I have 2000 miles on my super-charged. Since I have a pretty light foot and use the active cruise on the highway, I average about 20-21 mpg at an average speed of 50mph. Not bad for a 400hp 4200 lbs car.

All in all, this is a fun car. I look forward to my drive to work every morning!

 

In November I did a round trip California to Key West (main objective to visit Barber Motorcycle museum) and did6,978 miles with XF Supercharged. From first fill of tank to last fill was 6929.8 miles. Fuel used 332.332 gallons which calculates to 20.852 mpg. Fuel cost $838.74

This was all types of travel conditions lot of interstate, some secondary roads, some city. Speed was generally 10 to 15 mph indicated, over the posted speed limits, much of Texas is 80 mph on Interstates. Computer indicated well over 24 mpg between some tank fills. Not sure why some mileage figures seemed to be better than others when conditions seemed to be similar.