I'm getting an average 13.7mpg reading on my 2001 XK8. Shouldn't i be getting better gas mileage?

 

Not getting into too much detail with you, you'll probably get a few replies, cause I had a X-type, but simple stuff first: Tune-up, when was last one you had? Did you change Airfilter? Oil change? These can have an effect on MPG big time.

 

My car gets a Indicated 20 mpg overall. Don't know if the the mpg computer reading is accurate.

 

Also tire pressure is a biggy if you are running too low.

 

I would expect a bit better than that, even for the 4.0 and 5spd tranny.

First, what is your driving style? (a) you love nascar (b) easy on the throttle like there's an egg under your pedal or (c) you love golden girls

Second, is all your driving (mostly that is) in town, stop and go? Or do you regularly get on the highway? My avg mph shown after the instant MPG says 33 mph, and I have to get on the highway every day, twice, for about 20 minutes. That's what keeps my avg fuel mileage so high, at 21.5 right now.

Third, do you drive in Sport mode all the time?

Fourth, do you always use premium fuel? 93 octane?

New plugs, new air filter (as mentioned above), mass air flow cleaning, throttle body cleaning, maybe a BG44k can or two in successive fill ups, and I'm sure your mileage will improve some. Good gas

 

On a 1000 mile trip on the highway from Dallas to Illinois traveling at 78 MPH everywhere I could on the interstates, it averaged 19.6 MPG. When traveling in town cruising on warm summer nights, it averages around 16 MPG An I'm not light on the accelerator It's a 2001 XKR 4.0 SC I think you should be getting much better. I would consider doing all of the above.
Doug
2001 XKR Silverstone

 

I'm an average driver, No lead foot. Mostly drive in regular mode. I use 91 to 93 octane depending on the station. Never below 91. How does that instant mpg thing work? Mixture of city and highway daily. I'll try new plugs, new air filter (as mentioned above), mass air flow cleaning, throttle body cleaning, maybe a BG44k can or two in successive fill ups and see what happens.

 

I have a 2000 XK8 and do about 1/2 city and 1/2 highway driving with a slighty heavy foot and get just under 19 MPG. I do not think I could drive hard enought to only get 13 mph. Have you checked the MPH with real gas used to real miles?

 

I have a 2003 XKR, and on a recent trip from NY to FL, the average mpg was 24. This was driving at the legal speed limit + 10 mph.

ajn

 

Yes, agree with Glenn, do a manual calculation the next couple fuel tanks, see if its even close to the computer's math before you start relying on it as the gospel. And the avg fuel mileage is calculated from the current trip odometer, I think.

 

I just think it's the newer XK8 and XKR's that get better gas mileage.

I get anywhere from 14-16 mpg mixed/city, 18 mpg highway. That's with sport mode on half the time, ASC sometimes turned off. Sometimes I push her really hard.

 

Average gas mileage has so many variables. Once I did test how well the gas mileage would do on I5 in CA. Filled up the tank. Had to set the cruise control to 65mph, while everyone was passing me. Drove that way for about 3 hrs. The best it did was 26mpg.

 

Although I didn't buy a Jaguar for fuel economy, I do record all fuel purchased and mileage.

I drove 24129 miles in my last 2001 XK8 4.0 (50% urban and 50% long European trips) and used 5399.98 litres of fuel. This equates to 16.9 miles per US gallon.

Try putting the 'instantaneous fuel' on the display as you drive. It's surprising how lifting off the pedal only slightly can improve consumption dramatically without significantly increasing journey time.

 

GGG's reply makes me wonder. Did Jaguar alter the computer to US gallons for the US market, or does it still record imperial gallons?

 

I checked my mpg manually through 3 fillups and the math put the number within 0.1 mpg of the car's calculation so the computer must be programed to US gallons. Close enough for me. I get 19.4 long term in rural mountains.

 

Had a look at the Parts Manual. Both ECM and Instrument Pack are market specific so US cars must be calibrated in US gallons.

 

I average about 22 US mpg in my XKR, 25 on a long run. As has been said, a good service/tune-up would probably help. Of course, it all depends on your driving style; I'm sure I could average 16 without any difficulty at all if petrol were free

 

Hi Both A/B trips A set since I bought the car in October B set more regulary but both read average very close to one another at 22.3 and B 22.5.Mostly highway use but regular cold starts and 13mile runs.Would do better I guess on a long run.

Al

 

Drove mine home after I purchased it ,it. avg 23.8 mpg with the cruise set at 76 mph. I'm avg around 20 mpg around town.