Highest vehicle: LaVerda 750 SF motorcycle, got around 40 mpg
Highest car: '82 Escort at 28 hwy. Close is 2009 Odyssey that got 27 on a long interstate cruise once.
Lowest: BlueBird Wanderlodge with 12.7 liter Detroit. 6 mpg. 7 if I'm really lucky and have a tailwind on flat ground at 60 mph.
Lowest would probably be my 84 Corvette, which I bought in 1991 with about 75,000 hard miles on it and it was in bad tune and I think I was lucky to get about 17 MPG from it.
Highest is my Civic, I can get 40-45 MPG on the highway quite easily (and saw 50.3 MPG on a 2 hour "fuel economy run" that I did where I set the cruise at 50mph)
I had a 1990 Jeep Cherokee Limited 4.0L with the older Renix engine management. I could get 20 mpg around town and hit 24 highway once with the stock size 225/75R15 tires and transmission in comfort mode.
My 2000 Buick Century 3.1 V6 averaged about 23 mpg.
Current 2000 Jeep Cherokee seems to get 16-17 mpg no matter what.
Jeep sucked up to 5mpg on cold days with a 180 Tatar, that got corrected quick. Still is a hog, and is in the teens.
Got 50+not in the Harley, combined with stop and go at times.
The R1 is the most variable, can get mid teens or low 40s.
Best useful vehicle with good results is the RX. Can get 35 combine avg mpg, but it has to stay warm and NOT be driven by the Mrs
Best - 93 Chevy Corsica. Used to get about 35 out of that old 2.2
Worst - 88 Pathfinder. 31" tires with a WEAK 3 liter six cylinder. I think I averaged about 10-15 if I was LUCKY.
Highest was a 2002 Chevy Prizm, 1.8L, 5-speed MT; I averaged 39 mpg over 5+ years of ownership. A 2005 Scion xB, 1.5L 5-speed MT averaged 38 mpg over 5+ years of ownership.
Lowest was a 1966 Mercedes-Benz 250S, 2.5L straight six with dual carbs, 4-speed MT; I averaged 14 mpg over two years of ownership.
Originally Posted By: CCI
Lowest: 1 ton Chevy dually w/ Duramax and Allison; 9 mpg no matter what. If you pushed it off a cliff it would get 9 mpg all the way to impact.
Strange, My LBZ Duramax 2500 get's about 8 mpg towing a 40ft gooseneck with 200 transmission cores on it. I get 14 mpg empty beating on it.
Worse 1970 Plymouth GTX 440 6 pak 4.10 4 speed BUT the most fun to drive gas was 35 cent's a gallon about 8 to 10 miles to the gallon (had a problem with my right foot). Best 2010 mercury mountaineer current vehicle not so much fun. Gas 2.65 gallon. 18 to 21 miles to the gallon.
Worst: 1996 Jeep Cherokee 4.0L 4x4. Gets 15.1 mpg average. Best tank of 21.8 mpg.
Best: 2004 VW Beetle TDI. Got 36.8 mpg average. Best tank of 44.3 mpg.
Then I smartened up and crunched numbers with a calculator and realized gas mileage means nothing when you spend thousands of dollars a year on idiotic repairs.
Sonata gets 28.7 mpg average, best tank so far is 34.9 mpg and the Camry used to get 25.8 mpg average before I parked it. It's best tank was 37.1 mpg. Fuelly says 38.7 but that was downhill.
Best: modified VW A4 Jetta TDI - broke 60 mpg on several tanks...but usually mid 50's
Worst: 1997 Formula F27PC with dual 350's...never even broke 1 mpg
Worst wheeled vehicle: Either my old 1997 BMW 750iL or my current Silverado with a 6.2L. Averaged about 15 with the BMW, and average about the same when I run premium in the SIlverado. I primarily only run E85 in the truck and average about 12 in the summer and 10 in the winter.
I had a Cat bulldozer that was probably pretty bad in mpg, but assuming we're talking cars, worst would probably be the Jaguar Xj-12 but I had a Firebird that would be in close competition, best all around I've owned would probably be the Jaguar Xj-8.
I had a Honda CT110 that seemed to go forever on its tiny 5l tank, I read it can get up to 130mpg at 50km/h. I never calculated my mileage but it was good for the day of trails and back roads on a full tank.
My worst seems to be a tie between my '81 2.8l V6 Olds Omega, and the current CRV... Both mid 20's for a hwy tank.