guess my mpg, please

[young olds]

69 gmc long bed half ton 2wd, 350 quadrajet gm aluminum dual plane, manifolds with true duals to the rear end, th400 idk rear end gear 32" tall tires, 3950lbs. going to make a 374mi one way trip and want to give my self a fuel cost estimate. my dad got 12ish, i think, from iowa to washington, same truck except 2bbl on cast manifold and 235/75-15 with a motorcycle, rear end, tranny in the bed and towing a small trailer with another motorcycle in it.

[imjeff]

Without knowing the rear gear, that it's well tuned, load, or the size of your right foot, I'll say 8 to 15 or 6 to 17 in the mountains. Estimate high and be happy. I always try to keep my expectations at the bare minimum. That way I'm always pleasantly surprised.

Jeff

[young olds]

im assuming its the standard ratio for a 69 half ton. id hope it'd be better then the 12 my dad got on the 2bbl with that load. i keep it as well tuned as i can and will likely give it a once over before i head out. ill be empty on the way out so the 3950lbs plus two people

[RedRoad]

10-11 if using E-10

[MARKDTN]

Originally Posted by RedRoad

10-11 if using E-10

Probably pretty close. Also depends on if you are going 55 or 70.

[BlackedOut67shorty]

I get about 8 mpg with a 350 with a Holley, headers, turbo 350 trans and 373 rear, I think I have a 28 inch tall tire, my engine is tired though and has low compression

[67ChevyRedneck]

That's going to be quite a load to drag along... I'm going to go with 8-10. Towing my 18' boat with my modern Z71 with overdrive only got 12 mpg.

[67 cst swb]

I would figure off of 10 mpg... but, the changing of fuel prices from station to station, state to state, etc... and knowing that stations on the hwy are more expensive than the stations in town, usually blows my estimates off track anyway.

[young olds]

i certainly hope you guys are wrong
my dad getting 12 out of it with a 2 jet and that load gives me hope that without a load with a better carb, quadrajet, and taller tires( less rpms on freeway) i would get better mileage.

[67 cst swb]

Have you noticed the size of those secondaries you will be using in that carburetor on all those hills? Plus... as stated above, you do not get as good of gas mileage with E-85 as with the good 'ole gas we used to have.
I wish you the best. I would budget for 10 mpg at $2.50 per gallon. So, figure $100.00 for fuel one way. You never know you might just be surprised.

[slow-1]

Before I put the OD trans in mine I got 11 mpg all the time, towing a 20 boat or not, 350 with a q-jet.

[72MARIO]

I will be if you honest 10 will be pushing it....

[Steve-W]

Originally Posted by 67 cst swb

I wish you the best. I would budget for 10 mpg at $2.50.

Damn what are you complaining about.. Gas in the Netherlands is at It's lowest in 6 years $4.50,- per gallon!

[NC_John]

Originally Posted by Steve-W

Damn what are you complaining about.. Gas in the Netherlands is at It's lowest in 6 years $4.50,- per gallon!

And the Netherlands is the size of Maryland! You drive across the entire country with a single tank of gas.....

[harpo231]

I have a 67 c10 with 350 375 hp 4bb and if i stay out of the secondaries i get around 14mpg

[CG]

Originally Posted by NC_John

And the Netherlands is the size of Maryland! You drive across the entire country with a single tank of gas.....

European gas prices always seem crazy when you read about them, but their whole tax and political situation is completely different from the USA. Apples an oranges.

I googled square miles ... actually Netherlands is larger by approx. 750 sq. miles lol

Both beautiful places to visit =)

[Steve-W]

My 1969 C10 350/350 Will do about 15mpg running on propane (propane only costs $2,80/Gallon)

[young olds]

Originally Posted by Steve-W

My 1969 C10 350/350 Will do about 15mpg running on propane (propane only costs $2,80/Gallon)

gas is 1.85 for 87 where i live, going to fill up here and one tank should get me to my destination. im figuring 13mpg, will post what i actually get out of it after the trip, should be saturday.

[Steve-W]

Yugh.. 87 isn't that like filling up with water? We can't even get below 93

Years ago in Florida I drove a '78 grand marquis which i filled up 87.. The engine knocking was so bad I drained the fuel en refueled with 93 or 95..not Sure anymore, decades ago.

[special-K]

10 mpg. I didn't read any of the particulars, just made a guess that is safe for about any of these trucks.

Everything I own (except my Harley and diesel Jimmy) runs just fine on regular. I look at premium as a waste of money.

[young olds]

I got 14 out of it, tried to stay at 55-60. Wish I had cruise control

[young olds]

I always run 87 in it,