What mpg does you C3 get?
Burning Brakes
Joined: Nov 2005
Posts: 1,143
Likes: 0
From: Leander Texas
I have a '78 4spd. Before I installed the tuned port over the New Year hoilday with a Qudrajet carb I was getting about 18mpg on the highway. Mixed city/highway was just over 16mpg. My worst was around 14mpg (a little hard on the right most pedal) 
I will have to wait until the next fill up to report on the TPI mpg, as I had a full tank at the time of the conversion.
I will have to wait until the next fill up to report on the TPI mpg, as I had a full tank at the time of the conversion.
Instructor
Joined: Dec 2006
Posts: 105
Likes: 0
From: biloxi mississippi
thats not too bad a mileage as i got around 10-12 on my 78 pace before i changed the rear gears, went to a 5 speed overdrive, larger exhaust,aluminum intake, and new carb, and keep my foot out of it a lot more. been getting over 20 mpg now (the cost of all the changes will never save enough to cover the fuel savings but it is a lot more fun to drive with a lower bottom end gear ratio and a higher top end gear ratio.
Melting Slicks
Joined: Nov 2000
Posts: 2,507
Likes: 114
From: St. Louis Mo
Racer
Joined: Mar 2004
Posts: 484
Likes: 0
From: Guston KY
I have the same with the mods in my sig.
I get 12-13. I thought that was bad. I usually don't drive it without my foot on the skinny pedal. When's the last time it was tuned up?
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Thread Starter
Instructor
Joined: Jul 2006
Posts: 158
Likes: 1
From: Tampa FL
Dang. I need to figure out what to do. Like I said, I just got it and have gone over the engine with my buddy who has owned Corvettes his whole life.
The engine/filters/carb are all clean, and that is the mpg without the AC on. Of course, my foot is always hard on the accelerator, but it still seems low. What's the most common fix for this? (besides less acceleration)
The engine/filters/carb are all clean, and that is the mpg without the AC on. Of course, my foot is always hard on the accelerator, but it still seems low. What's the most common fix for this? (besides less acceleration)
Racer
Joined: Mar 2004
Posts: 484
Likes: 0
From: Guston KY
Dang. I need to figure out what to do. Like I said, I just got it and have gone over the engine with my buddy who has owned Corvettes his whole life.
The engine/filters/carb are all clean, and that is the mpg without the AC on. Of course, my foot is always hard on the accelerator, but it still seems low. What's the most common fix for this? (besides less acceleration)
The engine/filters/carb are all clean, and that is the mpg without the AC on. Of course, my foot is always hard on the accelerator, but it still seems low. What's the most common fix for this? (besides less acceleration)
Pull the distributor cap and see if your weights are free.
You may not be getting full advance. Also check to see if the vacuum advance is working.
Get a timing light and tune the puppy up. Somethin' ain't right.
Unless you are just being ridiculous on the pedal.
Burning Brakes
Joined: May 2004
Posts: 1,100
Likes: 3
From: belle plaine ks
18
!8 mpg highway. Bone stock 350, turbo 400, aluminium intake, 650 edelbrock, headers, hei and chambered exhaust. No performance camshaft. I wish to change all that some day but not right now.
Thread Starter
Instructor
Joined: Jul 2006
Posts: 158
Likes: 1
From: Tampa FL
I'm also replacing the cat with a test pipe this weekend. Hopefully that helps.
Le Mans Master
Joined: Oct 2005
Posts: 6,247
Likes: 471
From: Glen Allen, VA
something deifinitely doesn't sound right. My 79 L-82 4 spd gets around 14 and it's not stock. It's got a bigger cam, headers and true dual exhaust. It's also got 3.70 gear and a q-jet carb.
