Gas Milage?

[69halfton]

hey there guys, im looking for a winter truck to drive while the 69 is in storage.

ive stumbled across a 72 chevy Stepside SWB 4x4 with an automatic and A/C.

...its also has the tilt steering.

its got a 327 from the factory...everything else on the truck is stock as well.

if it was tuned real nice...what kind of milage could i expect out of this truck...

I only own 2wd trucks, so i dont know how the 4x4s do.

thanks...

[mrein3]

The best I saw with my mostly '71 4x4 is 13.5. That was with a tired 350 and 3-speed manual.

Now with a 383 and th350 auto I see 9.5, mostly towing my boat.

When my ship comes in I'll be swapping the th350 out for a 700r4. In theory that should get me back to 13 on the highway, when not towing.

[streetstar]

Originally Posted by 69halfton

its got a 327 from the factory....

327, and its a stock '72 ? Interesting

Sounds loaded if it has a tilt and ac though -- i'd guess 10 - 12 (max 12). Back when these trucks were designed, gas was cheap and 9-12 mpg was just part of the deal, nobody thought anything about it

[GM72K10]

My 72 K10, 350 Auto (4x4) with 15" tires and 3:08 rears gets about 12 mpg. FYI, No 327s offered as late as 72, either 307 or 350 for V8 4x4s.

[68350]

Somethings up with the 327. Last year in trucks for the motor was 68 and cars 69. The 350 replaced the 327. If it has a sb auto and 3.08 gears, I don't think 14-15 would be out of the question with an excellent tune-up, hei, etc. Just remember, on the highway, these trucks do suck the gas, but if you were to cruise county roads at 55, I would think 14-15 is probable. If you're looking for good gas mileage, buy a honda, if you're looking for something fun and exciting, go for it. Sounds like a nice truck. hope this helps.

[69halfton]

see thats the thing, I've already got fun and exciting with the 69. but i cant drive it year round, nor could i afford it year round.

so what would be perfect for my to drive daily would be a truck with a 292 or 250 in it.

but since those are extremly rare to find in 4x4, im looking at small V8s...I.E 327.

...i did think i was odd to find a 327 in that late of a model year, but the rest of the truck looked so un-disturbed, i took his word for it.

[streetstar]

Is it originally a Canadian truck? Maybe they used the 327's still for Canadians --- who knows

[Ol'Rover]

No GMC & Chevrolet discontinued the 327 in 1969....unless the truck is a 67-69 with a 72 front clip, that would make sence.

oh yeah, my guess with a tuned 327 is 15-18 mpg. My dad had a 327 in his 78 sierra (came from a 69 C10)

[streetstar]

Originally Posted by Ol'Rover

No GMC & Chevrolet discontinued the 327 in 1969....unless the truck is a 67-69 with a 72 front clip, that would make sence.

oh yeah, my guess with a tuned 327 is 15-18 mpg. My dad had a 327 in his 78 sierra (came from a 69 C10)

dude, you're high. 15-18 is what a new truck gets with an LS series motor. My bro has a new truck with a 6.0 and it only turns 13, and he drives like a grandma. Those old trucks just rarely get better than 12

I ran a stock 307 2bbl GMC (with th400) that never got any higher than 11 mpg --- then i swapped to a 4bbl - also 11.

As far as gearing goes ----- i switched from a 3:07 to a 4:10 or 4:11 and it only knocked it down to 10.

My th350 truck gets 12, because the transmission is more efficient ,

[67_C-30]

Dp

[67_C-30]

Dp

[67_C-30]

Originally Posted by streetstar

dude, you're high. 15-18 is what a new truck gets with an LS series motor. My bro has a new truck with a 6.0 and it only turns 13, and he drives like a grandma. Those old trucks just rarely get better than 12

I ran a stock 307 2bbl GMC (with th400) that never got any higher than 11 mpg --- then i swapped to a 4bbl - also 11.

As far as gearing goes ----- i switched from a 3:07 to a 4:10 or 4:11 and it only knocked it down to 10.

My th350 truck gets 12, because the transmission is more efficient ,

15 - 18 is exactly what my '69 C10 with a 350/TH350 3.07 gears gets. My 2000 Z71 gets 17 - 20 as good as 21 on the highway when I had the stock 265/75/16's on its. I have 33 12.50's on it now and it doesn't do quite as good, but still gets no worse than 15 in stop and go city driving. If you weren't getting any better than 11 mpg out a 307, it was either very tired or badly out of tune. I've never had a 307 that didn't get at least 15 mpg in these trucks. My 8800# 69 C-30 with a 383, SM465 and 4.10's gets 10 mpg. A carbureted SBC with a good tune - meaning the carburetor is working effeciently, good plugs, wires, points (if it has them) and good compression (not a worn out engine) - are pretty effecient engines. They always have been. If you buy an old truck/car that has tons of miles on it and determine that is tuned properly because its runs Ok, then yeah, 10 - 11 mpg (or worse) is "normal". The only exception is if the truck in question is low geared and you're running 75-80 MPH on the freeway. The MPG obviously drops dramatically when you buzzing down the highway at 4 grand.


Now you mentioned your brother is getting 13 mpg with a 6.0L. That means it's either a Silverado SS, and Ext Cab LTZ, or a C or K2500, all of which are MUCH heavier than a 67-72 regular cab 1/2 ton truck. You are comparing apples to oranges.

Look at the curb weight on them.

Silverado 1500

Regular Cab Standard Box

2WD - 4,453
4WD - 4,678

Regular Cab Long Box

2WD - 4,594
4WD - 4,946

Extended Cab Short Box
2WD - 4,994
4WD - 5,226

Extended Cab Standard Box
2WD - 5,105
4WD - 5,345

Crew Cab Short Box
2WD - 5,135
4WD - 5,379


Silverado 2500

Regular Cab Standard Box

2WD - 5,308
4WD - 5,554

Regular Cab Long Box

2WD - 5,596
4WD - 5,847

Extended Cab Short Box
2WD - 5,735
4WD - 6,606

Extended Cab Standard Box
2WD - 5,742
4WD - 5,983

Crew Cab Short Box
2WD - 5,899
4WD - 6,169





5,308 5,596 5,735 5,742 5,899
-5,554 5,847 6,006 5,983

[wibilly]

i think thirteen is pretty close to the best you'll get. my 71 shortened k20 has gotten a best of 11 with a 305 350 and 4.10 gears and 33" tires. my first tank in it yealded only 4mpg

[69halfton]

the ad says as a title: 72 chevy stepside...

although it does have a GMC grille on it....and i dont know the GMC grilles well enough to tell what year the grille is.

you can barely see it in the pictures, you see one and 1/2 headlights on one side.

WIBILLY: my dad drives a transport truck on occasion for the company he works for. he takes them down to nashville for a big pumper show.

He figured it out one time, he took a sterling with a 450 hp cummins motor in it, and a full size strait truck. and he averaged 9 mpg.

you would have done better driving a semi then your C-10

but thats all part of the game

[Ol'Rover]

Originally Posted by 69halfton

the ad says as a title: 72 chevy stepside...

although it does have a GMC grille on it....and i dont know the GMC grilles well enough to tell what year the grille is.

you can barely see it in the pictures, you see one and 1/2 headlights on one side.

ask for more pictures? and then google 72 GMC and see if u can match the grill, or if your near by go check it out and check the buildsheet it should mention the year there somewhere?

[wibilly]

my c10 is a k20

[69halfton]

yip. the email left as soon as i saw the truck advertized...if they come back and look decent...i will be stopping in.

[68350]

6.0L are KNOWN and PROVEN to get 11-13 in 2500HD. It's part of buying a truck like that, they don't get good mileage. I believe my 72 402/th400 3.08 1/2 gets around 15 if you drive it decent. I small block th350 should do better, but a lot depends on the driver, his or her foot, and the motors tuning. I can pull 15 out of a small block th350 truck, i know cause I did it for about 3 years driving a 68 gmc with 350/th350 3.08 posi.

[streetstar]

ok, ok, --- let me up, i've had enough ----- what you guys said