Hey guys, I have been happily driving my 2006 Evo IX since august, and loving everything about it. The car has 90K on the odometer and a good history of maintenance from 30K. I use the car for a easy commute to work, about 15 miles one way, mostly highway, and occasional city driving for running around and such. I have done the following maintenance since I got the car (In order of date):

New clutch Exedy Stage 1 HD Clutch, Installed at ER
New Boost pills vac lines, Mitsubishi
Allignment
Spark Plugs, NGK
Short Ram Air intake, Buschur Racing
ER retune (300 awhp)
Rear Diff LSD fluid, Lucas
Tranny Fluid, Redline

The car already had a Greddy 3" Exhaust with a 3" down pipe

I have done some long drives, all freeway, and stayed out of the boost completely, and it only seems to struggle to return 25 mpg. I was hoping I would get getting 27 mpg. Before you all get upset that I am expecting too much from the poor car, let me explain. My friend in college built an Evo for a friend that frequently got 27 mpg HW. with a full load of people, And I have read a number of post of people getting 27 mpg HW, with even more than 300 hp. Many guys who had their car tuned at ER have also reported getting up to 27 mpg HW.

Is there any thing else I should check on or replace that may be reducing my mpg.
The only issue the car seems to have is that the power surges on cold starts with no warm up period, I don't know if that is any indication of anything.
Is this just wishful thinking?

Thanks.

 

What are your tire pressures?

 

i was at 355awhp and only managed to get 18mpg on the highway soooooo 25mpg is damn good lol

 

Its the tune, I too get about 25-26mgp on the hw but in the past I have seen 27--several older threads on this-- think SD will be my next choice and direction for the increase. Good Luck!

 

I have an intake and TB about to get tuned. I have heard that 25mpg is essentially the goal for daily driving. Cold starts also get you terrible mileage and are bad for gaskets/seals in the motor. Wait until your car is at operating temperature preferably or until the thermostat opens and your idle drops (In the morning I always let mine run for a minimum of ten minutes and run back inside to finish whatever) Right now I am getting about 17mpg without a tune. So it is something that is happening soon.

BTW, I live in Snohomish!

 

I myself am getting such low mileage. What type of are you putting in? I've used many different gas stations with 92octane and chevron was my best outcome. They all have 10% ethanol mixed in, but chevron gives such better gas. It's because they use seperate nozzles which means it doesn't mix like all the other gas stations. Therefore, i got an increase of 3mpg just off of a different gas station.

Additional info:
15-17mpg street (most other gas stations)
19mpg street (chevron)

-i drive an evo ix mr staying out of boost with 3" tbe and 4" intake, no tune yet

 

Raptord: 32psi on a cold day, so I am assuming it might go up a couple of PSI when then are warmed up.
meckert: Sorry I don't know all the lingo yet, what is "SD"?
DiamondsR4_Evo: I avoid cold starts when ever I can, but lucky, all the roads are 25 mph before any major high ways. I drive really slow, short shift and basically idol until the temp comes up before I give it any boost. This winter I did frequently let it warm up for 10 mins as well, it was very cold in Lake Stevens
essej: Chevron every time, almost the same station every time as well. My second choice is Shell.

Thanks for all the info everyone, I will keep checking and see if anyone else has any comments.

 

SD= speed density. couple of recent threads

 

I run upper 30's cold tire pressure so that might be worth a few %'s of mpg.

Gas mileage will be worse in winter, I lose ~3mpg in the winter vs summer. Winter blends of fuel get worse mileage, and more time idling while waiting for the car to warm up affects it too. 25mpg highway in winter is pretty good, that's about what I'm getting. My all-time best is 29.3, that was in late spring.

 

Okay, that makes sense then, I had heard that about the winter blend gas as well. So if 25 mpg is above average, I won't worry about it then. I guess I will have to do some more testing in the summer and see if it goes up. I have also thought about running the PSI higher to help offset it. Does anyone one know what the highest PSI they would run on the Evo's suspension set up would be?

 

It mainly boils down how you drive but it seems your driving it right, for more mpg that is. But like some ppl here said it's your tune, heck if you want you can tune your car for 87 oct, if high mpg is what you want. On my evo ix with basic bolt ons and tune at 305 I barely get 16-17 hwy. but I drive with a heavy foot sometimes. Let's not mention what I get on e85.......13-15mpg hehehe, it's worth it!

 

Suspension is regardless for this. Just depends on what the max pressure the tire is rated for. My winter tires are only rated to 43ish PSI or something like that. I set them to about 38 when it was +5°C so it's probably around 35-36 now. In the summer I run 38psi cold for street use.

 

Actual tire pressure is splitting hairs for better gas mileage unless you are running on flat tires....

 

I agree with what most people are saying, when I had my talon tuned for my FP red it was making horrible gas mileage but safe power. Have you thought about switching maps to one thats more mpg friendly?

 

lol, I'm barely getting 21 hwy on a stock 05 with very low miles