dewman1999

iTrader: (1)

My lancer stock got about 27 mpg, which was about 4 miles less than the Eclipise i traded for. I added an RRM intake an mpg increased to 28 mpg. My thoughts were that with the addition of a custom catback exhaust that the mpg would again increase, and with some searching that is the agreement of most threads in this forum. But after that initial couple of weeks of hammering the pedal to hear the roar of the exhaust i set aside one tank of gas to test the mpg, the results were 24 mpg.

What could be the cause of this loss of mpg? I drove the car just as a did stock, and with the intake. I set the cruise at about 60 mph to and from work which is about 15 miles each way. I tried my best to resist the temptation to stomp the gas b/c i wanted a good reading. I have since done this again with 23 mpg.

When installing the exhaust the cat was not touched the guy just removed the stock piping and welded a 2.25" piping to the cat an ran it to the Magnaflow at the other end. Any help on this would be appreciated. At $1.95 a gallon i need all the help i can get.

gregivq

iTrader: (5)

I think it's normal to have a bit worse gas mileage after getting a catback exhaust. There is less back pressure. Get a piggyback or something and you'll get back your MPG. Get a header and kiss your MPG bye bye.

lookslikeanevo

iTrader: (23)

wow 27mpg, im getting about 23-24mpg with intake exhaust, fuel rail, and a lot of abuse all city driving...

KillahB

iTrader: (7)

Damn, I used to feel bad. I used to get 30 - 33 mpg in the Mirage. Now I am down to 19 - 21... but that is boosted. I dont feel bad anymore.

WADADLIG_OZ

iTrader: (9)

I can't believe this.

Out of 10 to 10.5 gallons of gas I get at least 270-280. The only way I get less is if I drive like an ***.

This is with I/H/E

Drive the car less aggressively if you want to save gas.
WADAD

CenCoastOZ

iTrader: (4)

I'm with I/E and get 31 avg. Car has 35k on it.

yellance

iTrader: (16)

may want to check tire pressure as well it does effect gas milage not a whole lot but every little does help my .02 cents

dewman1999

iTrader: (1)

If the responses there is a mixture of answers, but the majority are of you are getting ~27 mpg with mods. Could there be anything wrong with my car that would cause this low of a mpg? The 24 mpg that i recorded was driving non-aggressivly i calculated driving aggressivly and got 22 mpg.

imajinmyfx

iTrader: (8)

i get like 250 on a full gallon... i guess ur losing gas mileage cuz u wanna hear the sound of ur exhaust. when i first got my intake installed i lost a lot f gas b/c i wanted to hear the intake

uranium9v

iTrader: (3)

I think I'm around 20-21 mpg. Intake and exhaust really mess with the stock airflow sensor and the a/f ratio is all over the place. A tune may help you get it back in line. (like piggyback or afc)

rhyzin

iTrader: (1)

some kind of afc should help. with all the odd crap i have installed, i get at least 32-34 mpg. 36-38 mpg if it's all freeway. i once milked her for all she had and was able to hit 420+ miles on the tank(scary, almost didn't make it to a gas station and i really topped off the tank before that). when the gas needle is aligned with the last mark on the gauge, i'd have gone 380 miles.

you can check if the vacuum hose from the intake manifold to your fpr is damaged. if your fpr vacuum hose is open to the atmosphere, you'll be dumping the max fuel your fpr can handle into the engine. i think that's around 46 psi(don't quote me) whereas stock fuel pressure at idle is 38 psi and probably won't see more than 44 psi while driving. something like that. it's an idea.

edit: as a matter of fact, check all your hoses. one bad hose might be able to have the same effect.

WADADLIG_OZ

iTrader: (9)

I like what you are saying Rhyzin. When I had my PB on it stretched out the vaccuum hose going to the FPR to where it did not sit tightly. I am going to see if I can replace that hose and see how it affects my gas mileage.

You must have run the tank to the last drop to get the 400 plus miles. I know the most I have refilled is 11.3 gallons. The cars I think are rated at 12 gallons tanks. I think I manage 36X highway miles on that tank.

WADAD

MuslimEvoFreak

iTrader: (39)

I had the same problem when i installed a greddy TI exhaust in my evo. I installed a fuel pump and rail and now i have no problems. Good Luck

N1te

iTrader: (12)

You aren't the only one. I have an 02 ES with Intake, Exhaust, and a piggyback and I'm getting 22-24 mpg.. most of that is highway

Melaz425

iTrader: (23)

ive got, cai and catback exhaust and im getting 21-23mpg