I just picked up a 1985 GMC crew cab 6.2 to replace my 454 crew, the 85 is a4x4,4spd,4.11 and 190,000 well taken care of mi. I have gotten near 18mpg around town. what can i expect on an upcoming 1600 mi trip @65 mph? thanx p.s. by my math i would be turning around 2300 RPM. the truck runs great, no smoke and when it got above 35 degrees in the morning hear in eastern WA i did not need to plug in at night anymore. the truck runs about 190 degrees,thanx

Mileage will be highly dependant on how fast you drive. 60 mph will probably yield about 18 mpg, drive faster and it will go down. Only way to tell is by driving it and seeing what it does. Every engine is a little different.;)

got a 6.2 in my range rover 5speed manual, and did a 400 mile round trip to pick up a unimog, so 200 miles towing heavy duty trailer (1.5 ton) then loaded mog on it plus spare engine so total weight around 5 tons (legal limit in uk for range rover is 3.5 tons...) drove back at between 50 and 60mph and the mpg average was 20mpg...i`m happy with that!!

Wow, I am proud of mine getting 18-24 back and forth to work, Although with diesel prices being higher than gas I can about drive the jeep for as cheap now.

Although with diesel prices being higher than gas I can about drive the jeep for as cheap now.

diesel price in the UK is equivelent to around $8.50 US a gallon......

I pulled my boat 7K lbs from IL to South Texas. 15mpg!!! Going to get the boat unloaded 20 mpg!!!

Sorry to hear that, I would have to go on welfare if that happened, Just the facts.

I never got over 17 MPG out of my 1984 6.2L engine with a 4.10 and manual transmission. I got around 13.5-14.0 MPG with a camper on the 3/4 ton truck if I didn't drive too fast.

4150 lb Toyota Land Cruiser with 82 6.2, 3:70 gears 27% over drive. I'm getting 17.7 Mpg city driving. Took a 350-mile trip last weekend. Driving 70 MPH (2300 RPM) on flat ground with 5 passengers got 18.7 MPG.

I kind of expected a couple more MPG. I see claims of 23 to 28 MPG with this combo on the net. I just haven't been able to achieve what other people are getting or claim to get.

thanks for the info, i went 1300 miles and averaged 15mpg. 800 miles was towing a 6x10 wells cargo enclosed trailer loaded with 2000lbs including trailer, average speed 63 mph.

i have an 85 burd 4x4 1/2 ton lockouts, etc. if i remeber to have the axle free and don't let it idle and forget about it i can get about 16 running aroun town but i have gotten 23 on a long trip @ 65. But i have 373's out back.

p.s. I also use a premium Diesel fuel amoco is the best i have tried and i swear by it and use an additive regularly.

Most 4:10's without O/D get around 15.5 to 16. Most O/D's get around 20+. RPM's are the key factor. Keep them low, mileage goes up. That's with a light load, light throttle cruise driving conditions.

This info comes from the dealership days of listening to people complain about their new truck not making the mileage that the sales staff told them it would get before they bought it. Gee, sound familiar? They go from the showroom to the road and back to the shop to "Have you guys adjust my engine to get better mileage!" Thank God, there weren't any ALDL's or computers to plug into!

I have a 1990 suburban. 350 tbi gas. 40 gallon tank, 400 miles and your done. this is empty with me as its cargo asside from some other odd weights, speaker boxes and spare tire. that equates as 10 mpg unloaded all the time. this was uncle sam's forestry vehicle that had 3.73 gears and a th400. mind you, it wasn't good for the pocketbook, but it was a riot to drive for a big assed station wagon. now, put a car trailer behind it and another vehicle, I was happy to see 6 mpg. I'm now drivin a 85 6.2 with 3.07 gears, and with me roddin the heck out of it 10 miles to work and back, I'm still gettin 18. when it comes to gettin some work done, the answer is clear, use that 6.2 for what its worth. a gasser may be a bit quicker, but its not a good answer when it comes to overall cost. $80 every week for one tank isn't funny. $60 for both that takes you 2 weeks is more my style. take a deep breath, find a good radio station, and let your diesel do its meager job. put the pedal down further and you'll pay for it. let it get its job done and you'll be richer in the end. enjoy it while we still have sulfur in our fuel. when thats gone, the BTU's will go too. then we all will be driving slant 6 family cars. boooring.

take a deep breath, find a good radio station, and let your diesel do its meager job. put the pedal down further and you'll pay for it. let it get its job done and you'll be richer in the end. enjoy it while we still have sulfur in our fuel. when thats gone, the BTU's will go too. then we all will be driving slant 6 family cars. boooring.

:exactly:

I get 20 around town, and sometimes better with no load, driving with it in mind.

full bed loads tend to see it go up and down, 16-18.

Hey now, be careful about the Slant Six. My '64 Dart got parked (to give it a rest) on July 4, '03 with 500,834 miles on the clock. Yes, I rebuilt the engine, twice, but still, it got a steady 19 mpg and traveled 60 miles to work and back every day for thirty+ years. I figured it cost about $300 per year to drive and maintain for its lifetime, including the $450 I paid for it in '70 with 78,000 on it.

Hey now, be careful about the Slant Six. My '64 Dart got parked (to give it a rest) on July 4, '03 with 500,834 miles on the clock. Yes, I rebuilt the engine, twice, but still, it got a steady 19 mpg and traveled 60 miles to work and back every day for thirty+ years. I figured it cost about $300 per year to drive and maintain for its lifetime, including the $450 I paid for it in '70 with 78,000 on it.



there's always one of em. I find it humorous because my younger brother is still nursing one along. runs on 4 till warm, then gets its breath. fun conversation. have a good day!

I have a 1988 crew cab 4x4 with a ats turbo and pump turned up 410 gears. I drive it about 70 mph with 33 inch tires and I only get about 10mpg. Wish I was getting 18-20 like some of the other people are getting on hear.Do I have a problem or is it worse becuase of turbo and pump turned up.That is loaded and unloaded.

Superman