How much power MPG??

[christrucker]

Hey guys, just working through these questions on my motorhome. 83 g30 front end with a 6.2L turbo400 trans 203 transfer case (yes it is 4 wheel drive). I'm not sure the gear ratio.

First thing is, is the 6.2l a powerfull motor, should it pull the motorhome down the road with ease? I see people all the time with the 350 motorhomes pullinmg huge enclosed trailers zipping down the highway, should the diesel be the same??

Next question, what kinda millage should I expect. The guy I bought it from says he was getting around 17mpg. I drove about 600 miles last time I drove it and it was running like crap and wouldn't go over 55 (read my other post) and I was getting around 9mpg. So I am thinkning after I get the bugs worked out and get the power back up to where it should be, is 15-17mpg out of the question?? Thanks.

-Chris-

[john8662]

How large is this motorhome?

The 6.2 isn't a speed demon (well, some that is), in stock form.

The purpose of this engine is to get better fuel economy while maintaining power levels similar to a SBC 350.

You'll have to determine your gearing, but I'd wager a bet that you're running 4.10 gears in the differentials due to the size and that your van is a G30 (1ton). I also base this on your other post of going 70MPH with a 3-speed transmission, which wouldn't be very possible with 4.56 gears (the next lowest gears).

I'd say 15mpg would be what you're looking at, depending on speed around 65MPH. You may do better with slower speeds of course, these engines don't really like to rev and return good fuel economy, so an overdrive transmission would help.

4x4? That's pretty cool! I always thought the converted vans to 4x4 were quite neat.

J

[christrucker]

The motorhome is a 23 or 25ft, not sure, I'll have to measure. The rear axle is a 1 ton duelly. At 70 the motor is pretty reved, with a bit left, but not much. I was thinking 4.10s or a high 3s.

[AVM62]

Hi Chris, I have a 83 GMC Vandura G3500 23