Gas Milage Issues
 

Hey Guys,

I just bought a 1980 corvette and had to drive it home over a course of 9 hours across the states. I was expecting terrible gas milage, something around 12-15, but actually got between 22-24 (highway). This was about a constant speed of 65.

My mustang, a V6, typically gets around 20. Any ideas on what is up with this? I should be getting way better MPG than a 30+ year V8 car. I tested my mustang on mostly highway travel, again only going 65, and I got about 20.8 when I did the math. I am not flooring it, as during the test I tried to stay under 2000 rpms for the sake of the test. But I am getting about the same gas milage as if I was driving 75-80 at 2400rpm.

I bought the car used, so it possible there is a performance tune? I don't have CAI. Is that even really a good idea without any engine mods? As far as I know, the car is completely stock.

Thanks.

I'm not sure but my 08 GT gets about 24 combined an my friends 10 v6 mustang gets about 19-20. So I don't think v8 vs v6 has everything to do with it. I'm sure weight, liter size has to do with it as well. I actually hope someone can answer this question appropriately.

What year is your V6 Mustang? And how many miles? Auto or manual?

Maybe its takes less effort for the big v8 to get going and to keep going...?

Maybe some of the fuel system needs cleaning?

I havnet tried to gauge mine in a while, bu around when I got it like 3 months ago, on the highway around 60 -65 I got close to 30

2006, 76K miles, and auto.

Im sure the auto isnt helping, but you should def be getting more than 20.
I have an 05 5 spd. Accoding to the MPG gauge I get about 33mpg in 5th gear between 65-75. I dont know how accurate that is though. Id need to do a real calculation.
I just noticed your at Purdue too, thats awesome. I just graduated from there in May.

I would change the fuel filter, plugs, coils, and some injector cleaner. And change the air filter. All is very easy to do, hope that helps

Bad O2 sensor maybe? my F150 started sucking gas, put a new O2 in, good as new...never got a light.
I'd read the O2 is one of the biggest mixture feedback sensors, figured it was old enough to justify just trying one...right away power perked up along with MPG.
My 2000 mercury just got a check engine light 2 wks ago, scanner says rear o2 heater failing- daily mpg dropped from 21 to 16.5 on the dash readout ever since the light came on...hope to get time monday to get the fuel line on my old lincoln so I can get on the lift and change it...once engine is warm, I can clear the code, restart hot, mpg goes back up...shutoff to cold, it gets light again, mpg drops...weird.

my 06 gt gets 24 highway, the wifes 07 v6 about 25...peaks vary a lot, but a decent highway only jaunt, theyre pretty close on mileage. funny her 07 avalanche AVERAGED 24 on a 4000 mile trip once, last 2 ohio-colorado trips though was 21-22- thats a heavy vehicle to get those numbers...the 24 mpg was in really hot dry weather- impressive part is at least 750 miles of that trip were at high elevation back and forth from Canon City to westcliffe, and a trip up to victor thats over 10000 feet. 6 of us and luggage and probably 300# of rocks in the bed...kudos to gm for their tune and cylinder cutout :)

holy ****. my 05 5 speed averages 19-21 mpgs!!! wtf am i doing wrong!! lol

Nothing wrong. You are driving it the ways it was meant to be driven.

Even being a sixer?

Holy smokes! You are driving that Stang! :banana:

The best ive ever gotten was like a 400 mile drive I got like 26mpgs

Isnt Hughes Springs about 400 miles from everywhere? :jester:

Its bumphuck nowhere lol

Is there a way to check to see if an oxygen sensor is not functioning? I don't have any errors on my dash.

Yeah that does seem low. Especially when I average 19 on a good day :p