Fuel mileage?

[Plunkett]

I'm looking into buying a 77 chevy k10 4x4 with a 400sbc, 31x10.50x.15 tires, and stock gears. The guy is saying that it gets close to 14mpg and I don't believe this for a minute. I was just wondering what a truck like that would get for fuel mileage.

[choptop]

A well tuned engine getting 14mpg isnt out of the question. Alot of it depends on the amount a pressure applied to the skinny pedal. My 86 gmc 2wd gets around 20, not sure on the 4x4 yet, but it doesnt seem un realistic to get 14 or better.

[team39763]

I agree...driving habits make a huge difference.  I noticed a huge difference in mileage when I went from driving 70mph to driving 55mph on long trips.  I also tried to be easy on the pedal when taking off and did my best to "play the light" when I could.

[69byrd]

14mpg is not unrealistic it all depend on how heavy the right foot is

[Dragon]

14mpg is not unrealistic it all depend on how heavy the right foot is

Yep, his foot can be completely different from yours, so realistically he could...

[Irish_Alley]

in my 86 4x2 with a 350 i gave her heck and some how managed to get 14. it also depends on what brand gas you use it may sound weird but i was getting only 12 mpg with the cheap stuff like 10 cents under everyone else but when i tried gas it wasn't the most expensive but close to it in the area i went up to 14. since this post is up I'm only getting well last time i checked only 4mpg what would help that more a BB or more power to the Sb  or diesel and i don't want to hear "take the tires off" lol. another question whats the stock tq to a 350?

[choptop]

in my 86 4x2 with a 350 i gave her heck and some how managed to get 14. it also depends on what brand gas you use it may sound weird but i was getting only 12 mpg with the cheap stuff like 10 cents under everyone else but when i tried gas it wasn't the most expensive but close to it in the area i went up to 14. since this post is up I'm only getting well last time i checked only 4mpg what would help that more a BB or more power to the Sb  or diesel and i don't want to hear "take the tires off" lol. another question whats the stock tq to a 350?

[Unofficial]

I'll agree with everyone else on the driving habits. When I put my rebuilt 350 in, I drove it like a bat out of heck for the first tank and got around 9-11 mpg. I filled up, drove like a grandpa, and got about 18-20 mpg.

[Plunkett]

Thanks for all the replys. What do yall think the fuel mileage would be on a 81 k10 silverado 350/350 turbo transmission, stock gears, and 33" tires would be, assuming that I was light on the gas.

[Lt.Del]

stock gears, and 33" tires

stock gears could mean several different ones.  If it is a tall gear, say 3:08, with 33" tires, you will have terrible city mpg, but good highway.  With a 3.73 rear with 33" tires, better city, not as good highway.  If you are really light on the gas, ummm 16-18  (guess)?

[Captkaos]

15mpg isn't out of the question if you are driving it normal

[choptop]

in my 86 4x2 with a 350 i gave her heck and some how managed to get 14. it also depends on what brand gas you use it may sound weird but i was getting only 12 mpg with the cheap stuff like 10 cents under everyone else but when i tried gas it wasn't the most expensive but close to it in the area i went up to 14. since this post is up I'm only getting well last time i checked only 4mpg what would help that more a BB or more power to the Sb  or diesel and i don't want to hear "take the tires off" lol. another question whats the stock tq to a 350?

I didnt realize my post came up blank, what I meant to say is my 86 GMC Ex cab gets abot 20 mpg driven normally, which is hard for me most of the time, but somehow easy in this one. Now I havent figured my 85 K1500 yet. I know the speedo is way off with the 38's, it shows 35 when my gps shows 55mph. I know the tires do have alot of affect on mileage. From what I have figured, the engine needs to be around 2200-2500 rpms at 65-70 mph to be in the proper range as to not lug the engine, so regearing is a possibility. The thing about bigger tires is the same as driving a 1 ton expecting to get the mileage of a half ton. It doesnt make sense. Besides, you have to pay to play.

[69byrd]

I agree that driving habits play a major role in gas mileage, thats what I ment about the right foot. If I drive my truck right it gets about 14mpg local and in town and about 18 to 20 on the highway. I also think the grade gas makes a difference, my father has a 82 4x4 and it gets better mileage on the higher grade gas.

[Irish_Alley]

im running about 2k @ 50 and i think about 24k @ 70. i try not to go that fast so i cant remember what the numbers are. it also don't go no higher than 70 idk why but it just don't if i press the petal any farther down it lugs it. but anyway im not asking how to get 20 mpg with the 38's just asking what to do to get better ex. if you take a 454 and drop it in a car that used to have a 350 your mpg goes up so would it go up more if i was to drop a BB, diesel or upgrade the Sb maybe 383 or something along those lines.  the 350 thats in there now is the same one that used to get 14 in the 86

[Dragon]

I also think the grade gas makes a difference, my father has a 82 4x4 and it gets better mileage on the higher grade gas.

Well considering most Lower Grade Gas has more Garbage, mid grade has less, and the Higher Grades even less, then yes that is possible....  If you throw into the mix the brand quality, then you would be more likely to see better mileage by using a Higher Priced Brand(Chevron/Texaco), as opposed to the Lowest Price Brand(Arco/BP/Citgo/Etc)...  Even the lower grade Higher Priced Brand will offer better results, than the lower grade lower priced brand....