One of my older Malibus had a combination that averaged about 12-14 on the highway...it got old very fast dailying it 80-90miles a day on high test. Plus my GF at that time lived 35~miles away
My first tercel track day car got 17mpg at Summit Point, 14.5 after the turbo and big injectors. Still got around 35 highway.
These days my worse offending vehicle is my v6 awd highlander. Averages 19-22 in my mixed driving. Steady state highway distance traveling its 25-27. Everything else I own (that runs) is all 35+
"Excluding military", spoilsports!
Used to have a big block Ford 4x4 PU that got six MPG, loaded or empty, uphill or down.
Worst at the moment is my 81 Chevy 3500. Despite adding a troublesome FiTech injection and NV4500 overdrive it still does <10 around town and about 12 on the highway.
The rest of the fleet ranges from 15 - 47.7.
But the 47.7 car is to be scrapped so the engine can power something more interesting.
1978 Southwind motorhome with a 440, dad and I drove it across the US summer of 95'. It averaged 7 MPG, thankfully fuel costs back then were an average of .69 cents a gallon.
I went 4 miles and went though 12 gallons, but I assume a leaking fuel tank doesn't count.
NickD
MegaDork
7/22/21 8:30 a.m.
1995(?) F-350 4WD with a 460. Loaded, unloaded, uphill, didn't matter, it always got 8mpg. But, it would pull anything you threw at it. That truck was an animal.
'77 Delta 88 with the 403 V8. 13mpg average.
Edit - thinking about it, my '07 MX5 used to get about 6-7mpg on the track, so I suppose that's worse and within the context of the question. I'm sure other cars have been worse on track but I never checked gas mileage.
Towing a 20' car hauler (enclosed trailer) kills the mileage. My 2010 Expedition gets about 7.5 mpg with the trailer behind and my GT6 in it. Without the trailer, I get about 17 on the highway at 75 mph. My prior 1999 Suburban was about the same. It was the same when I had a steel Haulmark trailer as it is now with an all-aluminum Worthington. Must be just about purely a function of wind resistance.
I think my GT6 with triple webers gets about 8 mpg on the track, though I never really track that accurately. It's also constantly between 4500-7,200 rpm.
My ideal tow vehicle would be an SUV body (love being able to put everything inside an 8' long cargo space with the seats down) on a 3/4 ton pick-up chassis with a diesel, or a new Ford Godzilla motor or equivalent.
Snow plow truck about 2-4 Mpg
Corvette on track about 2
55 Chev with a built 350, 4 spd and 4.10 gear initially, then later swapped to 4.88-1.
I have no idea what the fuel economy was but I was driving it when I was courting the future Mrs. P, and though she didn't live far away, I was spending $50 a weekend in fuel. in 1984 prices.
I'll have to do the math and get back to you
I had a '67 Plymouth Belvedere II in high school with a V8, a broken gas gauge and a hole in the tank.
I used to put 5 gallons in every two days, which would pretty much keep the level below the hole.
And every other trip to the gas station, it got a quart of oil and a quart of transmission fluid.
That car was my worst offender.
