Whats your 67-72 chevy 2wd or 4wd gettin on fuel millage?

[Zoomin]

I'm getting close to 9 out of a 402. Some of the best use of decomposed dinosaurs I can think of.
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[Stocker]

Only time I kept track was around 30 years ago, on a mid-winter trip from the west coast to the midwest and back, something over 3000 miles. Had 8PR 7.50-16 bias-ply tires and the 55 mph NMSL was in place. I averaged 11.5 mpg on the trip.

I do record all the fuel, just don't figure the mileage, what with three tanks to keep track of. A few years ago I added up all the gas I burned driving to work in the winter. Short trips so the choke was always at least partially closed, and most mornings the truck ran several minutes just to thaw the windows. I was getting right at 2 mpg, yes two......

[68Stepbed]

Mild cammed 350/TH350/3.73, Holley 570 SA carb. I drove to Nashville last summer and got about 14-16 mpg as long as I kept it under 65. It averages 14mpg city because I run non-ethanol 93 in it. It does better if I mix in a couple gallons of race fuel.

[chopnchaneled]

Originally Posted by Wrenchbender Ret

1970 stepside 2 WD. 350 engine, 700r4 trans., 3.08 rear end, Q-jet carb & HEI. I get 16 mpg combination & 18 down the road. I was shooting for 20 but just can't get there.

My 68 swb stepper with a vortech 350 "converted to a 600 carb" and a
700R4 with 255x70x15 tires on the rear and a 3:73 is just about ready for some mileage tests.

On paper it should be turning 2111 rpms at 70 mph. stay tuned, i'm hoping for
20 mpg.

[cooter472]

I get 15-16 being nice to it, playing in it 8 mpg

[Transformula]

my 71 4x4, 400sbc, th350, 3.08 rear and 33x 12.5 gets about 10 mpg. I don't care if I get 5 and gas goes up to $10 a gallon, because it's still cheaper than a vehicle payment!!

[jeffg1010]

I am getting 12-14 in my '70 Suburban, but it is running a fuel injected Vortec 350. It could probably get better if I would change the gear, but I have it on a '99 3/4 ton chassis . . .it is geared a little lower, but she can pull damn near anything.

[mosesburb]

19-21 around town, 15-ish on the road.

[Painter D]

BBC 502, 4:10 gears = 5mpg

[jakeblues652]

lets just say under 10..

[helldiablo]

mine with 454/400= who cares..... not sure yet on my girls 68' 327/400

but my brother has a 67' with a 250 six banger/w 400auto .. and no bulls#!t he gets like 25-30mpg no bull.... a tank of gas last him a week and a half.. and its his daily driver.... he always says "a stock small block with q-jet running well should get 18-22mpg if it dosent get a better mechanic"... and from what ive seen hes right.. my 350 nova gets 20easy..

[swamp rat]

Originally Posted by Transformula

my 71 4x4, 400sbc, th350, 3.08 rear and 33x 12.5 gets about 10 mpg. I don't care if I get 5 and gas goes up to $10 a gallon, because it's still cheaper than a vehicle payment!!

Funny! I was of the thought that i could save muchoo bucks by buying a truck with better milage so i went out and bought one.... forgot about the insurance and lets just say.... LOL! Well at least now i have 2 trucks!

[ETsC10]

Don't keep track but I assume about 10-12 mpg all around. 327LJ, T400, 3.73 posi, flat tops, Edelbrock something, 268 RV and generally a bed full of crap.

My '78 olds w/403 gets about 5 mpg. Leadfoot her .

[C10-Driver]

1970 2WD SWB, running a 355 smallblock with close to 425HP... 10.5:1 pistons, Edelbrock Performer RPM heads with matching cam and intake, full roller valvetrain with a 670 Holley vacuum secondary. 700R4 tranny with a lock-up converter, 3:73 gears with just under 29" tall tire (275/55R17).

I did a trip last summer over one of our mountain passes and when I filled up with gas, I had to re-calculate 4 times because I thought I was wrong... Running 70-75MPH over the pass with some pretty steep grades I got close to 22MPG.

[BlackTopMotors]

Originally Posted by 69chevyshort

BBC 502, 4:10 gears = 5mpg

I bet that is a pretty cool 5 miles...wish I had a 502. Roger

[cam.man67]

Actually, I think my calculated economy may be off from actual fuel econ. My speedo reads 60 at 65, which is 8% off.

[clos69]

Does anyone have a link or website that calculates mpg?? Im planning on running a 454/700r4 with 3.08gears on 27/28in tires and would like to know how that calculates....

[cam.man67]

Ok, did some math this morning. Here's my fuel economies for every fillup since I've been checking, the corrected fuel economy, as well as a graph comparing the two.

[Stocker]

Originally Posted by clos69

Does anyone have a link or website that calculates mpg?? Im planning on running a 454/700r4 with 3.08gears on 27/28in tires and would like to know how that calculates....

You can calculate gear ratios and determine RPM @ speed with different tire diameters..... but you cannot accurately pre-determine fuel mileage simply because there are an incredible amount of variables involved. The best you can hope for is a SWAG based on input from others running similar equipment, such as you might find in this thread.

[mleeb]

I have a 2wd, BBC 402...just did the math on my last fill up and its 8.14 MPG. I think its better not to know, I don't like my thoughts of $$$ when I'm trying to enjoy driving my truck.

[1quik70]

I ran mine up to duck camp this year, and ended up averaging about 8mpg, I think it was a little better out on the road running 55mph. This was in my 71 SWB 4x4 with a 454 and TH350.

[waynep]

My 72 with a 150,000 miles with a 350 and a/t gets 10 mpg.

[cam.man67]

Any 6.2 or Cummins swaps out there that keep track of fuel economy? I'd love to hear them.

[1968CHEVYC10]

68 c10, worn out '75 350, q-jet, 3spd column, 3.73 and 31's.
8 around town, 11-12 on the highway doing 55. Best I ever got was 14, on a 120mi trip, did 55 the whole way.

Workin' on swapping in a 6.2 diesel, with a 4spd overdrive, hoping for 25mpg highway.

[trucks72]

I had a 2wd blazer a couple years ago. Had the original 350 with 70,000 miles on it. I put a 700r4 in it, with a vaccum operated lock up for the torque conv. Had 3.08 gears in the rear. I could get 23 mpg doing 70 on the road. Rpms was only 1600-1800. Best I ever got!!!