I am just curious about other X308 XJR owners and their fuel economy. I hit the wrong button on the turn signal stalk today (i get confused switching between cars) and I saw my MPG for the past 800 something miles was 14.0 MPG. I don't really care about fuel economy but I was wondering what some of you guys were getting. Is 14 MPG a reasonable figure of am I a leadfoot?

 

Intown - OK

Mixed driving - Lead Foot

 

My commute is a lot of 45-50 mph country roads and a few minutes in the city. I average 18 unless I'm honking on it. The avg mileage always reads about 2 mpg below actual according to doing the math when I fill up.

 

I try not to look!

The only positive thing I can say about the XJR's mileage .......

Its better than my Cayenne.

 

My XJ8, reset about 3 months ago (~2000 miles mixed), is currently 20.3 mpg.

 

well it looks like I am probably a bit of a leadfoot, although most of my driving is a bunch of 35 mile per hour roads for half a mile to a stoplight.

and yeldogt, I can agree with that, my supercharged F-150 struggles to get 10mpg

thank you all for your input

 

I've had my XJ8 for 12-years, and the long-term value for fuel economy has always been 16 MPG and my average speed about 35 MPH indicating a mix of highway and local weighted toward local driving. I did almost 23 MPG on a long trip recently. I always have the "sport" button on. I can imagine that an XJR would be a bit lower on the long-term MPG value than the XJ8.

 

My two XJRs both average 15.5 to 16.5 for mixed lead foot driving.

 

Man, I wish I got 14mpg in city driving. I'm averaging just below 11. Granted my commute is less than 2 miles each way but the morning is pretty much traffic free. At least its better than the 10mpg I get in the TVR. Don't think I have a lead foot as I get 28-30mpg in the X-type 5 speed 2.5 and close to the 80mpg mark on the bike.

 

The best I have gotten was 19.9 on a 300+ mile trip and the avg. MPH was 65. My mix commute mileage is 18 to 18.5 and the avg. MPH is around 34. This is all taken from the trip computer, I am too lazy to actually calculate the mileage as ultimately it is what it is! The computer just gives me a gauge of how heavy my foot is. If I use sport mode it runs about a full MPG below that average.

This is the price to pay for an "R", but it sure can be fun to play cat and mouse with a MB SL63 AMG as I did on my drive home this evening. He was a bit surprised by the stately Jag!

 

I am a bit surprised by 19.9 on a 300 mile trip. Was it all highway? As I mentioned earlier, on a recent long trip (from New Brunswick, NJ to Sarasota Springs, NY) I got nearly 23 MPG in my XJ8. I use the cruise control alot, but usually set it on about 10 mph over the speed limit. I also punched it a couple of times to get out of a pack when I got tired of drivers who couldn't maintain a constant speed. My Garmin indicated a max speed of about 97mph at one point.

 

I think you'll see a bit of difference between the N/A and the S/C cars as your supercharger is always being driven, even if you're not using it. I get 16mpg from my 2000 XJR which is mostly town drive/stop/start, but on a run it will do over 20MPG (US gals)

Meanwhile, my V12 XJS currently can't get the number on the fuel computer to be greater than the number of cylinders it has, but thats what 2nd cars are for :-)

 

Hence the old saying guys....they will pass EVERYTHING except a gas station!

 

As Sarc said, the S/C models are approximately 2 MPG lower than the equivilent N/A vechicle. I did do a couple of speed runs, but was also aided a bit by a tail wind.

 

I get really good mpg out my XJ8 in town & city I'm getting about 23mpg (UK Imperial) and on the motorways I can easy get 30mpg. Infact when I drove to France I was crusing for a 5 hour period and the computer was saying I was getting 34.3 mpg at one point, and that was at about 70mph and AC switched on (never off).

A lot of people don't beleive me when I say these figures, but I'm really not telling fibs-I've even had my friend who is a Professor of maths run the numbers and they come back about the same as what the car tells me. I can only assume that my care for the car is paying me back.

 

Either I'm really a wuss or my kitty isn't very thirsty. Ran down to Cold Lake from McMurray last weekend and with an average speed of 110 km/h got around 26 mpg(Imperial)/10.7liters per 100 km. I figure that's pretty good for an 01 XJR. I've seen over 29 mpg when cruising the flat country at 100km/h.