Mpg Poll

[rockdogg2020]

How many mpg are you getting with your setup? Tell the engine size, rear gear, trans, and carburetor.
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Posted via Mobile Device

[rockdogg2020]

Was getting 8 mpg with a 230L6, 3 speed, 3.90 gear, 1bbl carb. Now getting 15 - 20 with rebuilt carb, split headers, power steering, petronics kit, new vacuum advance, new thermostat, and 3.38 rear made the biggest difference.
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[newbe351]

11.5 city, not sure about highway as I never venture more than 20 -30 miles out but probably 14+ as best as I can estimate. 355 built roller cam sbc, 680 cfm QFT double pumper, RPM Performance intake, headers, etc. with Tremec 5 speed and 3:54 positaction. Was getting 9 at most with original 351 V6 and 4 speed tranny.

[Clyde65]

14.5 city/ 20.4 hwy, 4.8/4l60e/ 12bolt 3.73

with my old 350/400, I was lucky to get 8mpg

[luvbowties]

12 with all city--dunno re: hiway, but would think much better. Setup is stock '97 5.7 Vortec w/700R4, 3.73 rear, 27-inch tires, headers, GM-hei dist, and 'perfect' quadrajet. Was doing 11.6 city with 3.73, 3-speed manual, stock '68 307 w/good q'jet, stock points-dist, ex-manifolds w/duals, & 26" tires.

Think would do much better with smaller numerical rear gear. Even after tuning my governor, its slowest 1-2 change is ~16 mph, 2-3 change ~36 mph, and 3-4 change at 46 mph; thus I seldom get into 1:1(3rd gear) if I abide by our mostly 35 mph-zones--meaning I'm running in 2nd gear most of the time!

[vin63]

13-15 mpg in town, and right around 21 mpg on the freeway unloaded. My brake specific on the dyno is .377s at 3500 RPM to .394 at 4600 RPM, so the Kauffman cylinder heads have very efficient combustion chambers. My combo did not like anything above 28 degrees timing.

462 ci Pontiac with a 750 cm vac secondary Holley, 4L80E, 3.70 gears, but with 31" tall tires. After this rebuild, I'm going with a 4150 DP Holley to support a nitrous system and locked out advance, so I expect my mileage will fall off quite a bit.

[boucher racing]

Did about a 50 mile cruise, two lane highway mixed with stop and go.

MPG's = 17 all hand calculated with gps to measure distance.

Engine: inline 250, 8.5:1 compression, Blow-Thru Holley 350cfm 2bbl carb, T3 Turbocharger, 7 psi, HEI ignition, Stock intake/exhaust manifolds

Trans: 87 S10 T5 5 speed

Ratio: 29" tires, 3:73 rear

[Rich 5150 69]

350/350/373... quadrajet...17 MPG at 60...highway

[66clow]

I didn't know anyone's speedo actually worked? As soon as I can get mine working I'll let you know.

[rockdogg2020]

Lol. Mine didn't work when I got it, replaced the cable. Just figured out why my gas gauge doesn't work. New part will be in tomorrow.
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[newbe351]

Originally Posted by 66clow

I didn't know anyone's speedo actually worked? As soon as I can get mine working I'll let you know.

Mine is off by 18%. I check speed with a chart (RPM vs. MPH) on my dash and my tach. I check milage every fill-up and multiply miles by 1.18 then divide by gallons....

[61_FL_Apache]

Average 13mpg with a 305 V8, Edelbrock 500cfm, TH350, 3.08 and tires are 215/70/15.

Im sure its lower on the highway.

[T Herder]

65 GMC K1500, 305E V6, Mallory Maglite distributor, 1988 GM Throttle Body Injection, SM420 with a married Gear Vendors OD, divorced NP 205 transfer case, 4.56 final drive gears, BFG All Terrain 35's, plus a few other things.
I regularly tow a custom Sundowner 4 horse trailer with a GCVW of 18,000 lb. Log book verification shows the best mileage empty has been 18.61 MPG, worst, 7.2 MPG has been with a max load and pulling 21% grades in 4WD.
Average towing mileage runs 12.5-14 MPG, non-towing with a light load has been 14.8-16.4.
Best regards,
T Herder

[cru_zn_29]

I am running 5.7 TB 4L60E 3.73 posi 275/60/ 15 in my 66 SB 15 city 20+ on hwy trips. I installed this setup in 1995 and is my daily driver and have over 400 thousand miles and MPG stays consistent.

[theastronaut]

36.25 MPG in my '64... VW Bug. My truck is actually cheaper on gas; hasn't cost me a cent but pushing it sure is getting old!

[Sick5]

Originally Posted by theastronaut

36.25 MPG in my '64... VW Bug. My truck is actually cheaper on gas; hasn't cost me a cent but pushing it sure is getting old!

LMAO

[corvettejim1968]

Originally Posted by rockdogg2020

How many mpg are you getting with your setup? Tell the engine size, rear gear, trans, and carburetor.
Posted via Mobile Device
Posted via Mobile Device

12.2 mpg
230 six cylinder
3:73 rear end
350 tranny
1 barrel carb

[jonathan-m]

I drove mine cross country pretty much loaded to the gills and hauling a trailer full of stuff, and I managed roughly 12 MPG the whole way.

350 sbc

[tenni126]

Aside from my bikes, my truck is my economy car. I get about 14 around town, and right at 21 mpg on the freeway at about 68-70. That's off the GPS since the speedo is busted and I'm too lazy to fix it. I'm running a mild 350 with a 600 edelbrock carb and a 700r4 on 3.73 gears. I try to keep the RPM right at 2100-2200 on the freeway and it does well there. My modern-ish, fuel injected '96 Land Cruiser on the other hand does about 10-11 city and maybe 14-15 freeway on a good day. So I'm happy with the C10
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[cameyer]

I'm getting 17 with a mix of highway and stop and go in town, with a 327 with quadrajet carb sm420 trans and 12 bolt rear with 4.10 gears and 36 in tires

[weaintscared]

I'm. Hoping to get 15-16 with mine. Say yea right. Check out my build.