How many MPG does your C3 get?

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Dec 6, 2008 | 03:52 PM

1976 corvette

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Pro

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From: charlotte N.C

How many MPG does your C3 get?

Hi I have a 1976 corvette that seems when I step in it, it is always a half tank or lower. I was wondering how many miles per gallon does your c-3 corvettes.

Thanks,
Kevin

Dec 6, 2008 | 03:55 PM

'75

Le Mans Master

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From: McHenry Illinois

Smiles per gallon, I get a lot. Miles per gallon, not so many.

Dec 6, 2008 | 03:55 PM

MotorHead

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From: Who says "Nothing is impossible" ? I've been doing nothing for years.

My previous 550HP 406ci got 24mpg on the highway at 80mph, with TKO 600 in .64 overdrive.

I also tuned the carb correctly with a LM-1 wideband, if you get crappy gas mileage get your carb tuned right

Dec 6, 2008 | 04:08 PM

DIP51

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From: State of Confusion!!!

2018 C2 of Year Winner

Quote:

Originally Posted by Aktbird

Smiles per gallon, I get a lot. Miles per gallon, not so many.

I like that!!! I think it applies to most, if not all 'Vettes!!!

But 24MPG out of a 406ci

that's pretty good.
By next spring I'll have a TKO in too, then I can brag!!!!!

Dec 6, 2008 | 04:19 PM

MotorHead

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From: Who says "Nothing is impossible" ? I've been doing nothing for years.

What most don't realize is they have no idea if there carb is tuned correctly. You need to "see" what is going on. To do that you need a wideband O2 sensor like the LM-1. Going from a real badly tuned carb to a properly tuned carb you can double if not triple your gas mileage. I am not kidding here either.

When I got my 406ci back from the dyno shop the mileage was so bad I thought I had a hole in my gas tank. I am not joking, I checked several times for leaks. I re-jetted and the mileage was much better. This was before I bought the wideband. After I got that I tuned the carb perfect for idle, cruise and WOT

Dec 6, 2008 | 04:37 PM

SanDiegoPaul

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From: San Diego - Deep Within The State of CONFUSION!

Quote:

Originally Posted by 1976 corvette

Hi I have a 1976 corvette that seems when I step in it, it is always a half tank or lower. I was wondering how many miles per gallon does your c-3 corvettes.

Thanks,
Kevin

Mine passes everything BUT a Gas Station ...

It was tuned on a dyno, and I re-run it on the dyno every couple of years. My build now has six years and about 25K miles on it. Still strong but that gas tank size sux.

Dec 6, 2008 | 05:16 PM

hugie82

Safety Car

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From: Bridgewater nj

82 Crossfire with a 700R4 and 2.78 rear. 26 MPG at 70 MPH A/C off

Dec 6, 2008 | 05:22 PM

Roughrider

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From: Frederick Maryland

'69 convertible, 427/435, 4-spd M21, L88 camshaft, 4.11 rear = 6mpg regardless of how fast I drive it. In the neighborhood of 125 miles to a tank of gas.

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Dec 6, 2008 | 05:25 PM

Peterbuilt

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From: mount holly NC

2025 c3 ('74-'82) of the Year Finalist - Unmodified

2019 C3 of Year Finalist (appearance mods)

Smiles pre gallon, that's a good one.

Stock 350 TH400 3:08 gears= 14 MPG

Dec 6, 2008 | 05:25 PM

#10

Attfay Elleybay

Burning Brakes

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From: Sebastian Florida

L82 with headers/duel exhaust no cats, 200r4 and 4.56 gears = 23 MPG, mostly in town.

Dec 6, 2008 | 05:43 PM

#11

Frogday

Drifting

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From: Woodinville WA

I have two 1971 LS5 4-speed cars that each get 8mpg while driving like a normal person.

Dec 6, 2008 | 05:46 PM

#12

mrvette

Team Owner

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From: Orange Park Florida

TPIS ZZ9 cam L98 heads on a roller 355, 200 4r auto, 336 rear....22.2222 mpg at 90 mph.....cruise....

in town not so great,.....

but with the stock L48 and carb it got only 12-14 mpg.....

but that was 16 years ago...

just the injection about doubled that even with the munice and same gear set.....

so the newer/modern engine added about 150 hp, and then so the MPG went to hell right there....even with the overdrive....

Dec 6, 2008 | 05:48 PM

#13

capevettes

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From: Cape Cod, Mass.

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Well it's a 68 427/390 turbo 400 with a 3:08 rear end so it really isn't too bad on the highway if you stay on those puny primaries. Probably about 15-18 mpg. Around 10mpg around town.

If I'm jumping on it around town it gets nothing. It's not like I'm commuting in it though. The car is pure pleasure to put your foot into

Dec 6, 2008 | 06:02 PM

#14

Racer11

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Joined: Nov 2006

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From: McLouth Kansas

350 (lot of miles, engine not smoking but down on comp/vac) 350 turbo and 3.08 11-12 mpg highway at steady speed 65mph.

Dec 6, 2008 | 06:41 PM

#15

72ragtop

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From: bradenton fl

Quote:

Originally Posted by Frogday

I have two 1971 LS5 4-speed cars that each get 8mpg while driving like a normal person.

72 LS5 with auto and 3.08's, about 8 mpg or 150 miles per tank full.

Dec 6, 2008 | 06:42 PM

#16

kansas123

Melting Slicks

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From: Wichita Kansas

Stock 350 Auto about 12 mpg. Not sure but probably has TH400. Don't know the rear end.

Dec 6, 2008 | 06:49 PM

#17

70ZZ3 96LT4

Burning Brakes

Joined: Oct 2001

Posts: 911

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From: TN

70 coupe

best ever in my 70 350/300 turbo 400 with 3:08 in summer of 1975 driving from San Diego to Dallas loaded with luggage was 22 mpg interstate roads using the factory air. Today with the ZZ engine, about 17 mpg.
the 68 with no A/C and original 327/350 4-speed 3:70 gears last time I checked was 17-18 mpg on interstate. wonder what mpg would be with 3:08 gears?

Dec 6, 2008 | 06:57 PM

#18

69 Convertible

Burning Brakes

Joined: Feb 2007

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From: San Bruno California

With a fresh rebuild and the TKO5 speed, I got between 16-18 mpg. That's with mixed street and freeway. 3.90 gears. Tony

Dec 6, 2008 | 07:07 PM

#19

HBZ_81_C3

Racer

Joined: Jul 2008

Posts: 338

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From: Bowling Green Kentucky

With the combination listed below I get 12.42 mpg in town.

SBC 383
Forged Crank
Forged H-beam 6.00 rods
Forged pistons 10.41 compression
Late 4 bolt 1 piece rear seal block
ARP fasteners (mains & rods)
Comp Cams hydraulic roller cam XR-288-HR (236, 242 @ .050 with .520, .540 lift)
Edelbrock Performer RPM heads 64cc angle plug
Edelbrock Preformer RPM Air Gap intake
Quickfuel 830 cfm double pumper carb
MSD Streetfire HEI ignition
Headers with 2 1/2 “exhaust with Super 44 mufflers
Turbo 350 with 2500 stall converter