Hey guys I was just wondering what I could do to improve the gas mileage on my 99 Eclipse GS...I'm gettin like 22 mpg city right now. And I'm referring to things besides driving it hard and accelerating fast because I don't do all that too often...at least not until I make it faster. Any help would be appreciated.

 

22 mpg doesn't sound bad. I'd say stick to the basics: change engine oil / oil filter / air filter / fuel filteras scheduled, keep tires at proper pressure, keep exterior clean and waxed, avoid idling.
You may spend a few bucks on fuel system cleaning products, though I doubt they actuallly make any difference.

 

i dunno, i have a gs-t and stock i was getting like 27 mpg.. when i put all my shiot on and put the boost to 15psi... it jump to about 32mpg. of course a lot lower if boosting hard.... so maybe just open it up.. ie: air intake/filter, exhaust.... make sure you got good sparky's. clean the fuel sytem... replace the filter if needed... just remove it and see if you can blow thru it... if no it needs replacing... if hard to it needs replacing, if it is free then it is good.

 

Thats BS. There is no way you are gonna get 32 when you turn the boost up. Are you sure you didnt mean 22mpg cuz that would be more believable.

22 for a gs is definetly a bit low. I would do like the first person said, replace the air and fuel filters. Also do a general tune up (spark plugs, wired, ect)

 

I had a 96 Rs and I got it up to 27 mpg in the city
I put on 4-2-1 hearders wrapped in a fiberglass wrap, I put in a clod air intake, ( Not a short or ram air a cold. It dropped all the way to the bottom of the engine bay. I also put in a new o2 sensor and bosch platinum +4 spark plugs and new wires. Finally I had a muffler put on but I didn't have a complete exhaust.

On my 99 GS-T I was getting 27 or so mpg and then something happened and I have my manifold red hot no matter how I drive the car and I'm lucky to get 23 mpg.

 

I was told that getting rid of my catylic convertor (or however you spell it) would increase gas mileage...but at the same time I've been told not to do it. Any ideas on this??

 

Am I right in my assumption that the Fuel Filter is like most Dodge;s and in the tank?

I see it nowhere under the car.

 

no the fuel filter is out of the tank. It depends if it s a turbo car or not as to the location

Turbo = on the firewall near the battery side
non turbo = located on the fuel pump on topof the tank under the back seat

and about the catalytic converter, youll loose gas mileage if you remove it

 

So on my N/A 420A, its just hiding.
Pesky little bastard.

 

First let's go with the original question. The increase in gas mileage. Start with plugs, wires, fuel and air filters, fuel system cleaner, and an oil system flush (Basically a cleaner you can buy at AZ or whatnot that is mostly kerosene. It will break up deposits and whatnot from the old oil and sludge and liquidify it to drain out with the subsequent oil change). Also think about changing the O2 sensor especially if the spark plugs are black (meaning the engine runs rich). As for removing/gutting the cat... Depends on your states regs on emissions. If they're strict then don't do it. Cleaning it out will give you more power but not necessarily more MPG.

As for 99clipsgt the red manifold could be a problem with the turbo. Does the exhaust housing on the turbo get red as well? Have you tried spinning it by hand? Sounds like you had a lack of oil flow or coolant flow throught the turbo that could possibly have caused things to go bye bye in the cartridge section. Try taking the intake piping off and turning the turbo by hand to see if it feels tough or crunchy (For lack of better terms). Or if the cat gets red as well as the rest of the exhaust you may have a decent size clog in it causing a backup of the heated gasses. Just a few ideas i figured I'd throw out there for you to try to fix the GS-T

As for getting better gas mileage at a higher boost pressure? I think it's absolutely possible. Depending on how you drive and if you're trying to push limits. If you're driving conservatively and not trying to push the car I bet he would get a better gas mileage. Just a matter of finding the best boost pressure to be running for the octane fuel he's burning.