Anyone getting great MPG in their C3's
10-23-2006, 07:21 PM
#21
Instructor
Nope!
And I don't drive much over 65mph. 11 mph is about it. I can use middle grade gasoline or 87 octane as I believe the compression ratioi to be around 9:1.
I personally don't think you will find any carburated engine or Corvette for that matter to get the excellent gas mileage of the fuel injected engines. Fuel injection is just much more efficent on running an engine!
I personally don't think you will find any carburated engine or Corvette for that matter to get the excellent gas mileage of the fuel injected engines. Fuel injection is just much more efficent on running an engine!
10-25-2006, 12:20 AM
#22
Racer
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Originally Posted by corvette427
72 LT-1...nuff said....
Seriously though, about 10 if I am lucky. I know a 5-6 speed would help, but listening to that purring in 4th gear at 70 MPH is just too sweet a sound....
Seriously though, about 10 if I am lucky. I know a 5-6 speed would help, but listening to that purring in 4th gear at 70 MPH is just too sweet a sound....
71 LT-1. I couldnt care less about MPG.
10-25-2006, 12:33 AM
#23
Drifting
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Well, with the stock 305/180hp, I had always got 16-18 mpg in town and 22-24 on the highway. Now that I have my crate 350 installed, I seem to be getting about 12 in town, but I can't seem to keep my foot out of it yet! I plan a trip to the coast soon and plan to fill it up before and after. My guess is I should be getting about the same mpg since it is a new motor and has a new free flowing 2 1/2 exhaust, all the way back. But, I really don't care as it is so much more fun to drive now that it actually has power when you put your foot on the gas It was all show and no go for 26 years. Now, it still looks great (what C3 dosn't look great) and when you step on it at the green light, it is hard not to spin the tires!I love my C-3!
10-25-2006, 08:48 AM
#24
I get a solid 21 mpg highway cruising (80-90mph) with my 69 L46 350/350HP ...but it has a Richmond 6 speed and still at 3.70 rearend. Went with the six speed to still maximize my 0-60 and 1/4 ET's but also have great cruising rpms also as 80mph=2,300rpms. Get a 6 speed and a tuned carb or better yet EFI and you will be good to go. I love cruising with everyone on the highway at 80~90mph without breaking a sweat and hanging with the newer vettes and seeing the look on the face when after 30+ miles at 80~90mph I am still there with them not burning up my engine as I guess they are more use to older cars not having the gearing to hang with them at the higher cruising speeds for a very long time. I can get 300 miles on a tank of gas non stop driving...which is about 3.5 hours which by that time I need to stretch my legs.
10-29-2006, 12:48 AM
#25
My old '80 with headers could pull down a little over 20mpg on the hwy. My current '70, with little or no "tune" averages 15mpg going to work and back - mostly hwy with several stop signs. It has a 650 double pumper, but the previous owner disconnected the secondaries.
10-31-2006, 03:00 PM
#26
Safety Car
Originally Posted by jvette2
The best I get is 12-13 without putting my foot to the floor. However
9-10 other wise.
9-10 other wise.
11-02-2006, 12:24 PM
#28
Cruising
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I get 20+ with my 75. but i just put a t-56 in it. Then again i put hooker side pipes on it too so in town i can't help but to let it sing and that doesn't help mileage around town at all.
11-08-2006, 12:08 PM
#29
Burning Brakes
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Originally Posted by Duke94
I get close. 19+ MPG. You need an OD transmission to get there. I have a TKO-500 5 speed with OD.
What modifications are needed to install the TKO-500 5 speed in a C3 (1974).
I assume the drive shaft needs to be shortened. One of my main concerns is the shifter location. What brand/type/model shifter do use?
11-08-2006, 02:35 PM
#30
Le Mans Master
Originally Posted by timemender
Duke94 -
What modifications are needed to install the TKO-500 5 speed in a C3 (1974).
I assume the drive shaft needs to be shortened. One of my main concerns is the shifter location. What brand/type/model shifter do use?
What modifications are needed to install the TKO-500 5 speed in a C3 (1974).
I assume the drive shaft needs to be shortened. One of my main concerns is the shifter location. What brand/type/model shifter do use?
11-09-2006, 07:50 PM
#31
Race Director
Originally Posted by lukeee
Hi C3 people. C5 owner here. I'm condidering building a C3 for a project.
Are any of you running 350+ hp motors and getting over 20 mpg on the highway? I want a "spirited" car, but I also want to travel a lot. The C5's mileage amazes me. Can I come close with the right set-up in a C3?
Are any of you running 350+ hp motors and getting over 20 mpg on the highway? I want a "spirited" car, but I also want to travel a lot. The C5's mileage amazes me. Can I come close with the right set-up in a C3?
you C5 guys are funny.........you can't step back and expect what you have now.....i would think a spirited C3 driving experience would be too barbaric for you............now the looks you will get and the thumbs up will be more then you have ever experienced....just remember with these cars the saying is "Its a Corvette i didn't buy it for gas mileage".....i have what you are talking about and a 700r4 OD trans.... and i do not get over 20mpg on the highway and its pretty steady at 10mpg in town....as Lars says a speed demon is not made for fuel economy....if you had FI and a tremac 5 or 6 spd i bet you could do it though
Last edited by bobs77vet; 11-09-2006 at 07:53 PM.
11-09-2006, 08:56 PM
#33
Drifting
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Never measured the gas mileage. Why? Let's see 427, 390HP, Hmmmmmm.
I don't think my car, and vettes in general, were designed with gas mileage in mind. Just drive it, enjoy it, and the looks you get, and you won't need to worry about the gas mileage.
I don't think my car, and vettes in general, were designed with gas mileage in mind. Just drive it, enjoy it, and the looks you get, and you won't need to worry about the gas mileage.
12-31-2006, 12:34 PM
#40
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yes you can get that kind of mileage out of a c-3. I replaced my 3-speed turbo-hydramatic transmission in my 1971 coupe that i have owned for 23 years and bolted in a tremec 5-speed manual transmission. 22 to 24 mpg on the highway, and most important is my vette now has a manual transmission. This car is so much more fun to drive.