Gas Mileage?

[71Longbed]

Just Wondering what kind of mile you v8 guys get out there per gallon i think im getting around 7 is this normal for a stock v8 with a points set up 8mm taylor wires msd blaster 2 coil edelbrock performer rpm intake and edelbrock 1406 carb ?

[grayw0lf]

I peaked out once at about 13.5, doing about 65 on the interstate w/ a 305HO & Holley 650. HEI, stock cast intake

[JimKshortstep4x4]

We get about 12 in town and 15 on the highway. Loaded or unloaded does not seem to make much difference.

Jim

[GMC AMI]

All depends on gear ratio, how well tuned, good tires, fuel quality, shifting points and how much you lead foot it!

[Tx Firefighter]

I've averaged about 12 with all of my trucks over the years. I build pretty tame engines though.

My current truck with the 454 gets only 10 though.

[Bowtie67]

My previous engine setup best I got 22mpg, 350 Fuel Injected, Overdrive with 3.73 gears. Current setup 414sbc with Overdrive and 4.10 gears around 10mpg.

[bobs409]

My 69 short stepside weighs 3,700 lbs with 350/350, 3:73 rear gears is getting 16 mpg around town which I'm very happy with. Big highways aren't good with the rear gear so it doesn't do well there. I don't drive on big highways enough to check mileage.

[Cethern]

My 71 3/4 4wd get's about 11.2 with a 2bbl everything else OEM ( for now) and 3.73's Oh I did add a HEI with a MSD 6A. I would love to see 15....


Cethern

[tom hand]

10-15 is normal for these trucks...mostly depends on the weight of your right foot

[Huck]

My 72 2x4 LWB with 350, stock exhaust, intake, HEI, Edelbrock 1406 and a 5 speed would give me close to 20 over the road with 308 gears. Going to Hooker headers cost me about 2mpg and going to Edlebrock performer intake cost me another 1-2 mpg.

My 72 4x4 Blazer with 4 speed, 373 gears, 33" tires, stock exhaust, HEI, Edlebrock carb and intake give me 13mpg. Hope to back up to a stock intake and regain 2mpg.

[busterwivell]

My 402 is stock in my 71 1 Ton Longhorn. I have HEI, 700R4, 4:11 gears, and recently put on a new 1406. I just checked mileage with last fillup and did almost 12, the best I've ever done with this truck. Really need to change rear ends. A friend gave me another rear end, but I opened it up and it is 4:11 also.

[mr402]

71 Chev 1/2 ton, 3.08 rear, 402, turbo 400. Got 12.5 all the time. In town, highway loaded or not.
71 GMC 3/4, 3.54 rear 402, 4spd. Gets 11.5. Again seems to make no difference how I'm driving it.

[71Longbed]

leaves me wondering why im getting only 7mpg i think i have 3.08's and it makes no difrence wut i do on the pedal i still get 7mpg

[Brainchild]

I get 10 with a stock 350 Qjet,and a granny 4 speed.31" tires and I have no idea what gears are in it.It's a lot better than the 4x4 though,at least it's in the double digits

[skokie]

With 3.73 gears and 31 tires and a staock 350 I got 8-10 when I put 3.07s in 12-14.

[dinnut]

my speedometer doesnt work. but since i got my new edelbrock performer rpm and holley 600 cfm my gas mileage has horribly decreased over my quadrajet/cast iron stock intake.... will just these mods hurt gas mileage this bad?

[Brainchild]

Originally Posted by dinnut

my speedometer doesnt work. but since i got my new edelbrock performer rpm and holley 600 cfm my gas mileage has horribly decreased over my quadrajet/cast iron stock intake.... will just these mods hurt gas mileage this bad?

Most likely,Holley's like gas,or at least all the ones I ever had did.I know there are people who'll argue the point,but a Q-jet will get better mileage IMO.Holley's will aout perform it though

[shooter]

I get 12-13 with a stock 350 in a 72 2wd GMC with mostly hwy driving. I fill up every 3 days.

[Stocker]

I don't get mileage, I get yardage! With mostly short in-town trips, I likely burn more fuel warming it up for a few minutes than I do getting to work. I don't even check the mileage. It's horrible. When the secondaries open up, it's like flushing a toilet.
But I love the damn thing...

[dyingdeadman]

i get 7 regaurdless on how or where i drive. i think my carb needs some ajusting though.

[BurnoutNova]

with my 3.07's and 33's i get 7.5mpg, but i think i might get a bit more, because my odometer is probly turning over slower because of the taller tires.

im about tired of this crappy mileage... gonna have to get a honda or somthing.

[locab36]

69 short step. Rebuilt 350 (flat tops w/RV cam) 750 holley carb (68 main jets going to 66's though) rebuilt 700R4 tranny w/hyd lock up, 3.73 posi gears. I get 10mpg in town and as high as 16mpg on the hi-way.
After the build I drove it from Michigan to Kentucky then to Virginia and back home. Got better milage at the end of the trip. Pulling a 5x8 utility trailer too .

John

[Huck]

After a lot of expermintation, the only things that have really improved my mileage is the HEI distributor, the 308 rear and the overdrive transmission. Turning lower rps without the engine lugging is the key. However everything has it's price---the overdrive transmission swap--either 5 pseed or 700R4 will cost you about $1,000. by the time you're done. If you gain 3-4 mpg, you will need to drive about 30,000 miles before you break even @ $2.00 a gallon! Next best option is to find a towel head babe who's daddy own's oil wells!!

[Livrat]

Hmmmmmmm.. Mileage?? Whats that??... I get about 8mpg @60mph... Better at 50mph.... 468cu... Edelbrock Cam and intake.. Edelbrock Q-jet carb Stainless 2:19 valves in Microport heads... Keith Black 9 to 1 pistons.. Doug Thorley Tri-Y headers.. 3 inch exhaust, HEI ignition... 3:73 gears... 35inch rubber... 5900lb 3/4 4X4...
BUT.. the fun part is its about 450hp... Really catchs some off guard

[Robert1970C20rstbukt]

I get probably 7 or 8. Truck has a 350eng, TH400trans, 4:11.1 HO52 rear end, 31" tires.