I agree with what a few of you are saying about chipping diesel engines. I do not own a diesel passenger car but I have owned a 2006 Dodge 3/4 ton mega cab with the Cummings Turbo Diesel. I had it chipped from the factory (Predator Performance Inc - chip) and I clear 25 mpg+ on the highway. Wouldn't let it sit and idle too long though. :p

so what? no one owns a prius? dangit.

my car gets 28 mpg on average. nuthin special

Got 52 MPG on my trip to Maine last week in my 2000 Jetta TDI

Best I had was 50.8 with the Civic Hybrid.

That car = money saver.

Then theres the 99 ranger also...

I might get 16mpg if going downhill.

I owned a 2000 Jetta TDI for about 4 years (chipped for 2 years) and I averaged around 45mpg lifetime, with my best mpg for 1 tank of gas topping 53mpg.

My current car (2005 Volvo S40 T5) has averaged almost 24mpg lifetime and just over 30mpg for its best tank. Not bad, but it makes me miss my old Jetta sometimes.

And lately I've been commuting on my motorcycle (2006 Yamaha FZ6) and have been getting around 160 miles on one tank, so that's around 48/49mpg... not bad for something that can do 0-60 in under 4 seconds. :)

I remember once getting 18 MPG for the average on one tank of gas on my 1997 Buick Skylark (3.1L V6). If I drive smart I get like 24 - 28 MPG.

my 1994 BMW 540i gets 17mpg city, ~25 highway. I have achieved 20 city by reducing aggressive driving, but that's no fun...

04 RX8 So far my best was 21 of almost pure highway. Should be a bit better after I swap engines.

My Ranger with a 5.0L V8 and 4 barrel carb gets 27mpg (US gallons) if i drive it smoothly, even at high speeds, 85mph is only 2500rpm and the engine is quite efficient at that speed. Mileage drops at 50mph since it's lugging too low for 5th gear. That's better than the 2L 4 banger ever got and i can burn rubber for a block and go 140mph+ now. :)

Mercedes-Benz 200 1982 4sp automatic. I get 18mpg city and 24mpg highway. Pretty bad for a 2L 100hp (carb) engine :( Maybe caused by old transmission technology or something. I changed the air filter and spark plugs recently - beyond that I don't know what to do to improve things.