[mud.man.rj]

No such thing as good gas mileage with a full size 4x4 truck that usually weights 6 to 7000 lbs stock. Gears in the 256 range may lug it to much sound like mileage is no funage no power, keep the oil indistry alive like all good hotrodders do.

[crussell85]

is the vehicle a commercial vehicle? can/do you right off any of the gas on your taxes?

[RAYFIN]

"1,000 lb. 1/2 ton 4x4?"
I meant minus (-)1000 pounds not 1000 pounds total. I used poly racing seats, will make my own lightweight bed, make plastic inner fenders, maybe gut the doors, etc. I already made an automatic shifter that weighs almost nothing, etc.

"I grew up in PA and ONT and rarely needed 4x4. A good set of snow tires is all you need." That's funny. Come to Iowa in about 2 months. It is a commercial vehicle. I only paid $500 and the engine is smoke free with a new eddy carb and tires. Had to fix the rearend ($125).

Some great feedback and some spanking. Anyway I appreciate anyone that took the time to respond. I was a long time bracket racer and thank you all for the feedback.

I wonder if my 90 efi has enough back pressure.

[kc8oye]

"enough backpressure" there's another one of those great automotive myths.. any backpressure is too much. this is why we build free-flowing exhaust systems, to reduce/eliminate backpressure.


if money isn't a big deal, consider a TPI swap, or some other aftermarket multiport efi system. be ready to spend near $3,000 for it tho.

but again, this is like buying a new car.. with what the new vehicle is going to cost you, you can buy a LOT of gas.

when you consider your new vehicle payment..say around $500 a month. plus having to have full coverage auto insurance on a financed vehicle.. this could be anything from $200 to $1000 a month depending on the state on your driving record and insurance co... you can burn a lot of gas for upwards of $1000 a month!!!

[Furytom]

80's truck, V8 and good gas millage is a funny combination. I wouldn't even worry about it. Sure you can improve it a bit. But as said before from what 15 to 17 mpg? Saving a couple hundred bucks a year? Im sure you can save more on other ends of your business way quicker. As said here before if you want real good millage get a lil 4 banger import and your good to go. Otherwise just enjoy your truck the way it is. I love my 88 dodge W150, its doing everything Im asking for BUT saving gas!

[kc8oye]

I'm looking into building a Turbocharged 2.5L 5spd stick S10 for a little parts runner for myself.. I figure I'll pick up the mpg's of the 2.5/5spd combo, but the turbo should yield the power I need to be able to pull out into traffic :>

[sqzbox]

Hey RAFIN, what kind of mileage would make you happy? Then we'll go from there.

[BigRoy1978]

i was reading this thread and was reminded by what my grandpa said about his truck one day (84 four door, long bed chevy with a 502 and a 3 speed)

we were pulling my dirt stock car to a race one afternoon and i commented on how easily it pulled the car up big hills, he responded "yeah, you should drive it without a trailer, it will pass anything but a fillin' station!"

I know most of you have prolly heard that before, but its the reality of old trucks/cars, they just dont get good mileage very often!

[RAYFIN]

I guess we'll see what happens.

[RAYFIN]

Update: SO... not very good milage so far. I got the weight down to 4200 from 5000 Lbs. 600 edelbrock milage carb, performer intake, electric fans, ramhorns with dual 2.5 exhaust. 5x14 air cleaner. Turbo mufflers. Same drivetrain. I think 3.73 gears would help because the vacuum drops pretty fast while driving most of the time like it's lugging. BUT it is what it is and it's a blast to drive. I really like it. I may try a different carb and maybe 3.73 gears later on. For now it's a daily driver. I use it mostly for an (auto upholstery) shop truck. It's been super reliable. The 700r4 went out on my 90.... High gear clutch pack

[RAYFIN]

Ray Fin's Photos | Facebook

Ray Fin's Photos | Facebook

[RAYFIN]

Oh, I ran the numbers on the block. 1968 327 but it's a (unknown) AxxxxxxA crate motor so I'm not sure if it has a 350 crank.

[oldBodyman]

THE best mileage for SBC is the old Crossfire injection system from 1982-84.
Next would be an electric Q-jet setup w/700R4.

For what you have think BLOCK HEATER and use it faithfully. If you never cold-start and run on choke pumping cold oil with a daily driver your actual mile goes way up. You can also go with synthetic ATF in all the gear cases.

Have the front and rear ends checked for square with the frame, 'dog walking' scrubs off mileage.

Have fun with it.

[kc8oye]

the secret to good gas mileage has nothing at all to do with the engine...

but almost entirely to do with the loose nut behind the wheel...

that's right.. the DRIVER effects gas mileage a lot more then changes to the drivetrain will.

Intelligent driving, thinking ahead, planning your moves, holding the throttle steady as much as possible will do more to improve your mpgs than most anything else.

if you are the kind of driver that zooms up behind a slower vehicle.. stands on the brakes.. thinks about a lane change, then stands back on the throttle to make the pass, your mpg's are going to be a lot lower over all then someone who thinks ahead, and plans the lane change ahead of time and avoids having to slow down at all.

also, if you are a gas/brake/gas/brake/gas/brake kind of driver will hurt you a lot too.

or if you are like my sister who thinks the gas pedal has only two positions...all the way up. .and all the way down...

[mud.man.rj]

A good point was made on oil type which does actually make quite a bit of rolling resistance difference on synthetic from mineral based oil. On my last 71 Gm 4x4 I switched tranny (manual) transfer case and both diffs to synthetic iol and picked up 3mpg and that was in the winter months, shifted way better and rolled so easily, was actually surprised that it helped that much, the claims are true. also things like an advance curve kit for the distrib helps a bit and a rooler valve train, even rooler rockers alone help. It all ads up after a while. As you previously mentioned the optimal gear ratio also helps too.