Hey everyone. I have a new EVO IX MR RR and I'm seeing some pretty dissapointing gas mileage compared to the 8's. I have an RMR intake and a Greddy TI-C catback and I get on average 210 miles to the tank. My buddy's got an 8 with a 3 in turbo back... catless and he gets 300 miles to the tank!! BULLS***!!

I'd like to get 3 inches all the way but i'm pretty conservative and think I need a HFC instead of just going catless, especially being originally from a State with emissions inspections. So the question here is...

Am i getting crumby gas mileage because of the MIVEC? And what's better for me: Catless or HFC? I want to improve the performance of the engine while maintaining the best possible gas mileage. Any tips?

Note: Yes, I've already searched the forums and haven't found my answer... what do i do? Any specific parts people recommend like a flash or tune?

 

^^^ not familiar with an RMR intake, but if it is much more than just a drop-in filter, than you probably would benefit from getting the car re-tuned for it. Probably will help the car run more smoothly, and may increase mpg. For sure, a tune will increase the power on an Evo IX noticably.

 

dude....when my car was stock i was getting 180 average to the tank.....so be happy.....and if you want better mileage get a tune

 

im geting 300 on my IX SE and go catless

 

man that better be mostly highway.

I dont get anywhere near 200 on a tank. I do a mix of 50/50 city/hwy driving too. Now with more power, I dont even see 160 on a tank!.

 

i do city/hwy too the best i got it was 346

 

definately go catless

I usually get about 250 a tank....

 

getting tuned does not really help with MPG since our veichles are OBD2 they go into closed loop mode. you will save gas from a tune if you are running really rich when you go WOT.

 

But a tune can raise your voltage crossover so you stay in closed loop that much longer.

 

Me too!

 

I get 280 with mixed city/highway. I got crap mileage before my tune. For those saying it doesnt help, they are full of crap. We all know that NONE of us keep this car completely out of boost at all times. For it to stay in closed loop stoich operation, you cant give the car more then 50% throttle. Good luck with that!

 

Absolutely correct sir!

My car averaged 21 mpg (city/hwy) and then after Chris from AMS tuned me, he flattened out the fuel map a bit so that the car stays in closed loop a little longer...and guess what? I gained 2 mpg (city/hwy).

Not only that but the car pulls much smoother and is definitely faster. Best of both worlds I'd say.

I had a test pipe on the car, and switched to a HFC. The smell, risk of impounding (we don't get fix-it tickets anymore), were enough to trade for the few HP I'd be losing. BUT--I kept the TP so that I could use it at events like autox or drag.

If it's a street car, go with the HFC. Less of a nuisance and you won't notice the difference in power anyway.

 

This MPG talk all over the boards is crazy. You know gas prices are relly squeezing everyone when the forums for a such a high performance car like the EVO has people talking about little tips to get better MPG.

I am catless in my IX and I get about 250 per tank, but more then anything it depends on driving style. I have gotten as little as around 120 per tank if I really get on it alot and if I stay under control and no boost I have hit around 330 I think.

I dont think the cat makes much of a difference, mostly its just your foot that affects your MPG.

 

I now get 330 per tank doing 100% highway but when I first got my EVO I was only getting about 200 per tank. No one has mentioned the fact that a new engine gets crappy mileage until it breaks in and loosens up a bit. Once my EVO hit 15K I was getting much better mileage but when I finally got it reflashed it was better still.

 

Does the cat actually affect gas mileage though? Not having one is better than having one in that respect? I couldn't stand the fumes whenever I was driving around town...friends and family started to complain. The kicker was when I found out the city was going to start impouding cars that had illegal parts on them instead of just citing the driver. EEEK!

Sooo AMS HFC went right on.