I have 245-40-18's and on my first tank I got 19.93 mpg checked by the fuel I used and miles driven. I'm very happy with the mileage for what the car is.

 

try replacing the air filter with a KN filter..I got 32.4 miles a gallon on the highway..went 1000 miles

 

Pretty much. It's all relative anyways. And all the owners comparing cars have the same computer .. almost(to forestall nitpickers).

A return run @ 35psi made zip difference .. almost. Certainly nothing that could not be explained away by normal variance. Handling and ride were almost the same.

 

I live on the edge of London mostly my driving is in fairly heavy traffic..driven gently with just the occasional "hitting it" to shame the boy racers I get 18.8 to the gall (normally aspirated 3.2 V8) On the subject of gears mine is really so smooth I doubt I could say what gear I am in!
When gunning it in sport then I am usually concentrating keeping it where I want it to go, on our fairly narrow and busy streets, I don't have the time to count the changes!

Well ok I don't right now cos kitty's in for a replacement engine. Will be intresting to see if the replacement gives same results?

 

What, do you have a Jaguar Hybrid? I've wondered about running K&N on my Jag. If I could bump it to 32mpg, I'd be there tomorrow. I've resisted K&N after all the discussions of MAF being adversely affected. We already have enough trouble w that.

 

I've put over 5000 miles on it no trouble yet

 

What filter are you using now

 

i believe it's a Fram, just standard filter. What year and model are you driving? That's incredible mileage. Seriously, I'd replace it in a heartbeat if I could get that.

 

No offense, but I too often see people on car forums of any make claiming to get unrealistic gas mileage. These cars have horrible aerodynamics and a V8. Unless it was 1000 miles down hill or a mpg reading for only like half a mile, I'm doubtful of 32.4 mpg. For an average, that would mean you would have also driven a long distance with mileage that is greater than 32.4mpg too. That is better than many modern aerodynamic 4 cylinder cars with 6 speed automatic transmissions and much narrower tires/rims. Well, unless you are using the UK gallon system for measurement.

 

Maybe he used that instant MPG display, mine read 56mpg once as I came to a stop light.

 

Just rummaging through my users manual (looking for radio codes for when I get Kitty back) and came across this MPG chart
3.2L V8
urban cycle 16.5 ...........yeah thats kinda close I'd say
Extra urban cycle 30.8....Not so sure on this one !
combined 23.5...............Hmmmm they should try that in my neck of the woods
UK Gallon remember!

 

I have an 04 xj8 and I also had a fram. The KN is only $ 45 and remember the mileage was on the highway 32.4 city was better too and Im getting a little more response from the engine too

 

24.5 on a trip between San Diego and Los Angeles and back last week, 240 miles, all at about 70 mph... 18 is my typical for city, 20.7 is long term 2 year average (I keep long term on B, reset A for short term calcs).

I've always been amazed at the good mileage this car gets relative to it's engine/performance and aerodynamics.