Bad gas mileage!!!

[slow6]

Re: Bad gas mileage!!!

im not talking about just fluids, plugs, and wires

[rhouse21]

Re: Bad gas mileage!!!

There are so many threads in here with people trying to find and arguing about little tricks that may or may not have any effectiveness in increasing mileage. Here are the facts.

1. Make sure that your car is really in as good of running order as you think it is. You have to look a bit beneath the surface here because strange little things start to go bad as you creap closer to 100k (or 200k in my case). Look for things like clogged vacuum lines and air filters, dragging brake calipers, worn bearings, bad o2 sensors, blocked cats, etc. My upper manifold gasket was leaking coolant into the inards of my engine for at least 100k miles, having god knows what effects on my motor, but I had no clue because there were no external leaks. Sometimes big issues can go undetected for a long time because they aren't obvious.

2. If you care about mileage, drive like a grandma. This is a tough one. Most grandmas don't drive f-bodies, but shifting into high gear and setting the cruise control at 55 (or 65) will actually save a lot of money (on gas and speeding tickets... if it doesn't bore you ro tears first). I personally got into a long, drawn-out debate on this forum a while back about cruising in high gear vs low gear, but remember the dreaded 1-4 skip shift in the v8's? It was put in specifically to force guys to shift into higher gears sooner to keep their revs low and raise GM's average fleet mileage to comply with government requirements. Think about it. If forcing F-Body and Corvette owners to go from 1st to 4th at low speads was enough to offset gas guzzling full size pickups and raise GM's average fleet mileage, it just might save you a couple of bucks at the pump.

3. Don't run anything but regular unleaded unless you've tuned your computer to require more octane. Running any octane level higher than required by your engine is just throwing money away. "Top Tier" gas companies (like Exxon, Chevron, Shell, etc.) are require to put the same cleaners/detergents/additives in their regular grade as their premiem. I like to baby my car as much (or more) than the next guy, but this is one area that you really can spare the cash and not feel bad. Like I said, the extra octane won't buy you any extra power unless you've specifically reprogramed your computer to require the costlier stuff, and it won't make your engine last any longer either. I've been using good old 87 octane for 10 years and >200K miles. Save your cash.

4. Lighter cars burn less fuel. Most of us aren't willing to strip out our stereos or interior trim to save a tenth of a mpg, but cleaning out the trunk and not hauling your weight set will give you a little boost.

Hope this helps.

[badinfluenceRS]

Re: Bad gas mileage!!!

My upper manifold gasket was leaking coolant into the inards of my engine for at least 100k miles, having god knows what effects on my motor,

and it still runs?
did you not check the oil for 100k miles?

[99pewterv6]

Re: Bad gas mileage!!!

hm, maybe I should make a sticky on when parts should be changed (tuned up).
Wouldnt mind doing it if I'm guaranteed a sticky

PLEASE do. Too many people ask about this, this would be good for a quick reference. However the sticky list is getting long.

[screamin86]

Re: Bad gas mileage!!!

i think im still gona change my plugs and wires this weekend and make sure my cat/exhaust has no clogs or anything. i can actually tell a diff in the pickup now since the brakes are fixed not a lot but some. so far the best mileage ive gotten with this car since ive owned it was 28mpg interstate on a trip w/ windows down for 3hours and on the way back i had two more passengers and more luggage nad ran a/c coming back up mountian and got 26mpg. worst ive gotten is prob around 14 or so ut like i said lately it has been 16-18/19 at best and im on interstate everyday with cc set usually on 70 and just cruise

[99pewterv6]

Re: Bad gas mileage!!!

Hey screamin86 whats the easiest way to tell if your calipers are locking up? Also I average from 18-22mpg and thats 30% city 70% highway. This spring i'm going to try the seafoam to see if that helps with the mpg. Have you tried seafoam yet? Theres a sticky at the top of the forum on the steps to do that.

[slow6]

Re: Bad gas mileage!!!

uh, jack up the wheel, turn it by hand (does it drag?)
(unless its a rear wheel)

[99pewterv6]

Re: Bad gas mileage!!!

I think it did drag a little last time i check but that was before i changed my pads and rotors. I will have to check when i change my oil next time b/c its all snow and slush here right now. So any drag at all is bad?

[screamin86]

Re: Bad gas mileage!!!

yes drag=bad i love this car its very pretty but im ready to get rid of her :( poor mileage and only decent performance eh... time for ls1 or a CTD :) but yea any drag is bad im going to do what i can to see if i can get any better mileage i did notice a lil better ive gone 260miles as of now and just abut to hit empty so its better

[v6mOtOrhEAdftOp]

Re: Bad gas mileage!!!

I go about 280-290 per tank, but that's with ti full and me driving 30 miles each way to work and back.

[screamin86]

Re: Bad gas mileage!!!

i got about 18mpg on my last tank i did real good on the first half but i will admit on the second half i did do a lot more city driving since they were cruise nights so the stop and go didnt help but there is a great differance. although its actuallyt starting to snow here so letting it run for 5-10mins to help thaw it out a little prob doesnt help my mileage much either plus me sitting in parking lots with car running for 20-30mins so the heat will work

[Camarorulz]

Re: Bad gas mileage!!!

Good thing you got the problem fixed. Brake failure is a scary thing. :O

I have a cam and high stall converter and managed 250 or so from my last tank driving in normal conditions. It worked out to be a little over 18mpg, and that was purely city driving. Always calculate your mpg when you fill up, don't just go by how many miles you got. I think my gas gauge is a little whacked, because I can drive when it reads far past empty.

Driving at slow speeds will also affect your mileage. I've been driving around in the snow lately and it KILLED the mileage on my last tank, not to mention the colder engine operating temps. It takes forever to warm up.

[screamin86]

Re: Bad gas mileage!!!

im easy putting 600miles a week on my car and its a lot of mixed driving especially when the weekend comes since everyone goes out friday and satyurdaynights but during the week i try to take interstate more than anytthing just because its quick and easy for me and everywhere i need to go is right off the interstate usually. on friday or saturday nights i can fill up around 7or8 and only drive like 15miles till like midnight or a little later and use more gas than usual just because of stop and go and occasional hard take off:spank:

[John G.]

Re: Bad gas mileage!!!

**** i wish i could get somewhere around 230 to a tank...when mines at 90,XXX miles and gets bad gas...yea sum of it has to do with a heavy foot but i dont like floor it or anything like all the time...jus evry now n then.160 miles to one tank is terrible! :( cold air intake-flowmaster 80s-no Cat-and mid grade octane

wow, 230 per tank (16.8 gallons?) is really bad...
:eek: