What kind of gas milage are you guys get out of the strait 6 with a standard trans?

I'm kind of thinking about buying a 67 but the only way I could justify having another van is if I used it as a dayly driver. So if anyone has a ruff Idea that would be really cool.

Thanks,

First KIllakans, Welcome to the site.

You can "Search" the forums for topic's you have questions on and find most of what you need.

https://vintage-vans.forumotion.com/search

Try these threads and hopefully answer your questions.

https://vintage-vans.forumotion.com/t19813-improving-gas-mileage?highlight=Mileage

https://vintage-vans.forumotion.com/t10766-gas-mileage-question?highlight=Mileage

https://vintage-vans.forumotion.com/t3569-mileage-for-a-240?highlight=Mileage

Dan

Thanks alot for responding to my question. I think that 16mpg is really good. I dont think I'm getting that out of my work van know.

In one word, BAD gas milage.

Thats why i went to a fuel inj V8 with a 700R4

M1D

What do you figure your getting with that engine setup M1?

I have a 3:36 rear end in my 65, 250 cu in, 6 cylinder, and 15" tires just like Donivan and I get around 18mpg here at sea level if I stay off the pedal....

I havn't dothered to calculate it but I can tall you it is much better then the old six with the carboretor that flushed fuel like a toilet bowl. and I would have to keep it on the floor to get 55mph out of it.

The V8 hardly has to do any work to move the van and the 700R4 has such close ratio gears the engine never has to work.
On the highway at 60mph with the TCC ingaged the cruise rpm comes down to 1750 rpm with a 3.42:1 rear gear.

Of course I can get real bad milage buy doing burn outs and hauling a$$ on the highway. Like the last road trip where the van was completly filled with another stripped van. Must of been 1/2 to 3/4 ton load and on that 8 hr drive over the mountains averaging 75MPH . not less then 60 up hill and closer to 100 down hill I think I clocked in at about 13MPG.

I don't ever bother with gas mileage because I only use my van for fun.

M1D

Yeah im not to mileage concerned ,was just curious ,, I know the last time I checked on a long run I got 13mpg and that was a really bad headwind on half of it. carbed 350/700 with 4:11s, my old 65 GMC i had in high school was doing good to get 15 with a 230 3 spd /3:36 gears. Im not sure if gas was up to .50 a gallon then or not ,,so didnt care then either ,,lol

What Don said.

M1D

not comparing apples to apples here ?? All must be equal for a comparison- the 14 " tires will roll further+ highre rpm's & further distance traveled - until High gear -and then in od for a 30% reduction?/-- 15's not so far= and in 1-1 ratio=also slipage with the torque converter?? v/s clutch?/ Must compare apples to apples and at what weighte are each van- same type carbs,Ign, see where im leading to?? Just thinking & comparing??

so just tell what your van has and what kind of gas milage
you get with your setup, my first 68 with 350/350 with a
holley 600 never got more than 12 mpg, had 336 rear and
15 inch tires.
we have a club member that has a 250/700r4 336 rear and
15 inch tires that has been converted to tbi and he gets
20 mpg.

My '67 is a 283 V8, not the six, but on a fairly long trip over mostly level roads, a year or two ago, going about 55-60 mph, I measured about 18 mph, mostly highway.

I'll have to check it again, though, because I just adjusted the valve lash preload and it's got significantly more power. Used to be it was struggling to get up to 60. Now it's no hot rod, but it can get there no problem, and the difficulty is keeping the foot off the accelerator for slower starts and lower top speeds. The increased power's increased fuel consumption may be balanced by the fact that the engine is now running more efficiently. These vans are not particularly aerodynamic so no matter what, wind resistance is a major factor in fuel economy. Fuel injection would probably be a major fuel saver, as well. I think I've taken the little 2bbl carb as far as it can go.