redwhitekat

Anyone like me hate driving on the hwy with your vette I find on my 74 4 spd if you are going 70 80 miles an hour the rpms are just so high for a v8 and car is Loud cause of the high rpms and mufflers that its just uncomfortable plus gas mileage is down the drain with those rpms so high

MrJlr

I know what you mean about the rpms and noise.....
But there ain't nothing better to me then going 80 in my vette!
I love it!

WHITE 1974

Girlfriend hates it,I love it loud no talking mine is automatic but still screams pretty good on the highway.I used to have a 75 close ratio 4spd with a 3.70 rear end true duels and headers....now that was loud on the highway

MrJlr

Lol.....no talking!!!!!

randommj

My 74 L48 auto pushes about 3000-3500 rpm on HWY speeds, I also put on some side pipes so there is absolutely no talking, ear ring a bit afterwards, but I still like doing it every now and again, I like feeling like I could fit under the semi next to me.

11.8 MPG HWY isnt too good either...

Miles

redwhitekat

Ya the noise is bad lol for no talking. Hopefully my new carpet with insulation under it will quite that down a bit

gq82

You've got to be kidding me...there's nothing sweeter than the sound of a Chevy V8 accelerating onto a highway or cruising down one.

ddanis60

I just got my 81 last week. It has a few small mods, but i wasn't feeling all comfortable about being over 3k on the highway. i also calculated gas mileage for the first time yesterday, and when i saw an average of 12.. i wasn't pleased because i figured something was wrong. After seeing this thread.. i guess things are pretty much normal, ha! I havent been at that high of rpm since i had my 5 speed cobra with 4:10's at 80mph.

I guess after getting out of my z that gets 26 on the highway, it was just a shock. Is there anything in particular that could slightly boost mileage on my L81? Its got headers and cat-less exhaust.

-Dave

Easy Mike

No.

randommj

If you got it for gas mileage, you got the wrong car

Miles

ddanis60

no, i certainly didn't. i have a 91 Honda as a dd, along with a few other vehicles. i really dont care much about the gas consumption in the c3, but that doesn't mean i wasn't shocked at 12.. on the highway!

ironwills76corvette

Picked up my first Vette (automatic tranny) a couple of weeks ago, and got to drive it on the highway for maybe 30 miles. It was an adjustment seeing the RPM's up where they were. I am really accustomed to everything having an over drive and multiple gears which allow the engine to lope along at highway speeds. I loved driving it and although mine will rarely see the Interstate, if I ever change the tranny I will look into swapping a 200R4 or maybe 700R4.......

Easy Mike

Is the computer still on your 81?

When tuned, I could get 18 highway out of my 74 L-48. I could get 16-17 out of my 80 L-82.

If you can get no more than 12 out of your car, it's time to find out why.

Procrastination Racing

Let me guess. You are 40 years old or less.

Probably closer to 30.

The reason I say that is your entire life has been mainly in cars with overdrive transmissions and are used to the extremely low revving engines of OD transmissions.

Remember, until 1975, highways were typically 65, 70, 75, and even 80 mph depending on the location. Some areas had NO speed limit (reasonable & proper).

You aren't hurting it.

F22

I love driving on the freeway or highway with my 74' 4 spd. Keep it at 65 to 70 and just immerse myself in the experience, since I didn't have a stereo installed yet. With the headers, it's sort of loud, but that's just my L-48 talking to me and telling me how happy it is to get out!

PS: a complete JBL system is getting installed soon! 550 watts RMS!

gbvette62

You should try it in my 62. 4:11 gears (sometimes even 4:56's!), 4 speed, headers and a very tired old set of Cherry Bomb mufflers. Add king pin front suspension that was designed over 50 years ago, rock hard springs, park bench flat seats, and a huge steering wheel; by comparison, your 74 would seem like a brand new Caddy!

Actually I love it, but then I might be a bit of a masochist. At a steady 3,000-3,300 RPM, the 62 really does make a sweet sound though.

Something doesn't sound right with your 81. Unless the rear gears have been changed out, it should have a 2:87 rear. With those gears, I'm thinking you should be in the low 2,000 RPM range at 70?

The EPA combined mileage for the 81 Corvette was 14 for the 4 speed and 15 for the auto. The highway rating was 22 for the 4 speed and 21 for the auto. In normal driving, I use to get around 14-15 with my 81 automatic, and though it's been a long time since I took it for an extended run down a highway, I'm pretty sure it use to get me between 19 and 20 at a 70 MPH cruise.

I can see where 12 MPG could be possible under really hard driving, or in stop and go traffic, but it seems a little low for normal driving conditions. If that 12 MPG was on the highway, I'd have to say that something is way out of whack!

80Baby

Speaking of 5-speed, I'm surprised those guys haven't chimed in on this thread yet. I sold the 4-speed out of my '80; I'm putting in a 5-banger for noise and mileage. There's that old adage "If you can't afford the gas, then you can't afford a Corvette." I don't necessarily agree. The oil companies are gouging us and I simply hate giving them my money. That's why I suck it up and drive a Toyota Yaris to work everyday. It's all about the principle. So a 5-speed in the Corvette is a must for me.

taylor34

For comparison sake, the 72 I just acquired got 15mpg on the drive home (250 miles) at an average of 65 to 70mph...and it's definitely not tuned in properly, as it can't stay running for the first 5 to 10 minutes unless you're giving it a little gas, and when you stop it smells pretty fumey. I did not do any flooring it or anything, I was afraid I would kill it and not be able to get it started again.

dc502

gq nice vette what color is that, looks like mine is similar.

4SPDL81

My '81 L81 with 4-speed manual transmission is at about 22-2300rpm at 60-65mph...my gas mileage in town is 13-15 and on the highway has been as much as 17-18...car is stock...good luck!....