How to cure poor gas milege

[nelson84]

What to check for?

O2 sensor???? How to check for a bad O2 sensor?

Would leaky injectors cause poor milage?

My 85 vette uses more fuel than my 84 vette?????????? WTF?

 

[ex-x-fire]

You've got 3.73s in your 85, right? Those aint highway gears.

 

[boomdriver]

Lower gears have always been used to "simulate" power and enhance accelleration but the trade off was poor economy since the engine had to spin over faster.
Taxi cabs run some gears so high or tall that they barely pull away from a stop lite but on the freeway at 55 mph the motor is barely above a fast idle. This works since it only takes (example->) 45hp to maintain speed. The rest is used getting there. they're looking for more economy and less performance. The polar opposite of the corvette mentality. Since 84 CF were not monsters in the HP dept when they were made, it makes sense to drop the final ratio so it felt stronger than it really was.

Either that, or somethings wrong..otfl

 

[vetteoz]

What to check for?

O2 sensor???? How to check for a bad O2 sensor?

:eyerole

It intrigues me how some people can be on forums for years ;
handing out their often wrong " expert " opinion to anyone who will listen and giving the impression to the lesser educated
that they actually know what they are talking about.
But when push comes to shove ,
they don't even understand the basics of their car and it's operation

Would leaky injectors cause poor milage?

If you leave your garden hose running ;do you get a high water bill?

 

[boomdriver]

;lol

:eyerole

it intrigues me how some people can be on forums for years ;
handing out their often wrong " expert " opinion to anyone who will listen and giving the impression to the lesser educated
that they actually know what they are talking about.
But when push comes to shove ,
they don't even understand the basics of their car and it's operation


;lol
if you leave your garden hose running ;do you get a high water bill?

 

[Hib Halverson]

:eyerole

It intrigues me how some people can be on forums for years ;
handing out their often wrong " expert " opinion to anyone who will listen and giving the impression to the lesser educated
that they actually know what they are talking about.
But when push comes to shove ,
they don't even understand the basics of their car and it's operation



If you leave your garden hose running ;do you get a high water bill?

It is rare that I make this award on the CAC, but....


"vetteoz" gets the Beacon of Reality Award for those statements


And, as for fuel economy...

"nelson84" the gas mileage your 85 gets depends on several factors
1) tuning...you need to look the calibration to see if it's too rich
2) axle ratio...if you have short gears, you'll get worse fuel economy than if you had stock gears
3) if the car has an automatic, trans. calibration...maybe it's staying in lower gears too long or the TCC strategy is not right or maybe the TCC isn't working at all.
4) driving habits

Those ought to give you some places to start looking for improvements.

 

[LLC5]

:eyerole

It intrigues me how some people can be on forums for years ;
handing out their often wrong " expert " opinion to anyone who will listen and giving the impression to the lesser educated
that they actually know what they are talking about.
But when push comes to shove ,
they don't even understand the basics of their car and it's operation



If you leave your garden hose running ;do you get a high water bill?

Nice.

Vetteoz, I take it that you are not exactly a firm believer in the classic internet engineer motto: "If I paid money for it, it has to be better".

 

[nelson84]

You've got 3.73s in your 85, right? Those aint highway gears.

3.54 but still I think it is using touch fuel. I gave it a tune up with new cap rotor, plugs & wires, k&n. It helped a little bit but even before the 3.54 gears it would only get about 16mpg when the 84 would be in the high 20's but read about 32 mpg.

 

[Pete K]

3.54 but still I think it is using touch fuel. I gave it a tune up with new cap rotor, plugs & wires, k&n. It helped a little bit but even before the 3.54 gears it would only get about 16mpg when the 84 would be in the high 20's but read about 32 mpg.

Must be the Renegade creating all of the awesomeness.

 

[philbillyvette]

Must be the Renegade creating all of the awesomeness.

that's funny, i don't care who you are......

 

[Low drag - High speed]

I get 20 mpg with my '84 ...

... and I haven't even been into the engine since I bought it a month ago except to check for leaks and levels. My previous '84, which had over 150,000 miles as opposed to 53,000 on this one, got about 24 mpg after I tuned it because I used platinum plugs, synthetic oil and synthetic transmission fluid. I'm sure most of you are aware of the superiority of synthetics over petroleum-based lubricants. It lubricates better, lasts longer and doesn't decay like the other.

BTW ... got more torque and hp, too. Can't wait to jazz up this new '84.

 

[Schrade]

Give him a break. If he admits he doesn't know something, that more than some...

If your engine is modded, you can expect only more power, and not usually better fuel economy.

Air, fuel, and fire.

Is the air filter clear?
Is the fuel pressure [spec]? (what SHOULD it be for your mods??? no one knows the answer to that question, so that's a crapshoot - all you can look for is leakers)
Is the timing still electrically controlled? Or completely mechanical, with vacuum advance mechanism? Wires? Plugs?

Squeeze balanced in all 8 holes? Static and dynamic?

With mods, as I always say, you're in the dark (unless you have a new vehicle, with baseline specs, and mod baseline specs.

 

[nelson84]

Must be the Renegade creating all of the awesomeness.

That sounds about right. I always get the right answers on CAC.

 

[bb2kksy]

I have a 79 350 , 3spd auto, 3:55 gears. at 10mph or 110 mph I get 13 mpg.. Still love the car.

 

[English Guy]

Hi Nelson, is that a mini clubman in your photo's background? I have'ent seen that sort of mini since I was at a custom car show in the early 80's,real rare car.

 

[Marv02]

When my many O-2 problems just about everytime I got a service engine soon light.

There only $20.00 US and about 10 Minute job to swap it out.

My main problem was the Long tube headers I end up installing a heated O-2 fixed the problems.

What kind of plug readinngs do you have.

I also had a fuel leak before I did the motor swap that was under the A/C Unit you could not see where it was comming from untill you pulled the A/C out the way.

It was the sencond time it did it when I just said screw it just pull the motor out to get a good look at everything.

 

[nelson84]

Hi Nelson, is that a mini clubman in your photo's background? I have'ent seen that sort of mini since I was at a custom car show in the early 80's,real rare car.

Its a 78 mini pickup with a 1300cc engine. Around 110 hp. Chicks dig it. It draws a crowd anywhere you go.