Hi.

I just bought a Evo 5 recently and it seems to be using alot more fuel than expected. I spend $40 NZD each time I top up my fuel which gets around 17L of 98 and that goes after around 100kms of driving average.
The car is running 22psi external wastegate for which it is road tuned to. I'm thinking of lowering the boost to around 14psi as that much power is unneeded for just street driving in New Zealand.
To do this I'm thinking of running a boost tap to 14 psi, will I need a retune after this or can I run everything the same? And would I be seeing a huge increase in fuel economy compared to the current?

It was doing around 70kms off 17L from the day I bought the car till a week ago where I fixed a problem in the power steering pump and it started doing 100kms on 17l. I've had it scanned a few times and had no errors show up so not sure if it is the oxygen sensors putting out a wrong afr.

The car used to boost hard you could feel a big pull but now it seems as if it has gone alot slower I'm not sure what's up with that.



(First turbo car so I don't know as much, still learning)

Modifications include:

- Jasma full exhaust
- Tial external wastegate plumbed to exhaust
- HKS RS intake kit
- Walbro fuel pump
- Stage 2 Heavy duty clutch
- Super sequential blow off valve
- Sard fuel pressure regulator
- BC Gold adjustable suspension
- Bigger intercooler kit

Thanks!

 

Hey man, how are ya? Where in NZ are you?

Evos are thirsty. 17L/100km gives you about 14 MPG which is lower than what you should expect (I get 20-25). To accurately gauge your fuel mileage, fill up, zero your trip meter then when you are nearly empty refill again and record precisely how much it takes to refill and what your trip meter was at.

Lowering your boost won't do much, it only affects how much boost you are running at full throttle, so unless your launching and racing light to light you won't see any change.

Have you had your evo long? You can get used to the power and it does begin to feel average after a while. At the moment my 350whp (23psi) evo 9 doesn't impress me a hell of a lot at full throttle.

If you have the resources, try to check your AFR to see what your ratios actually are.

 

Post some pics of your car

 

My thoughts exactly! Sorry I can't help you with your problem.

 

Thats normal fuel use to me, it was more with my Airtrek, but my Evo I haven't worked out as its a dedicated race car

 

Hey. In Auckland, hbu?

Yeah I always fill up and reset the trip meter, gets around 100kms average off $40 of 98.

Have had the Evo over a month now, so expensive to run, I hardly take it anywhere and have already spent over $900 on fuel.
Don't have any resources to check the AFR unfortunately so not sure what I should do about that as I don't want to go out buying new sensors and find out the current ones are fine.

@Nemsin & BWS EVO




Will look bit better once the spot lights are in tomorrow
Haven't done much to it so far since getting it since all my cash has gone on running it, but once I've sort out the fuel efficiency I will start working on it some more.

 

Nice man! I love yellow Evo's. I wish mine was!

 

did you sort it out as i own a evo 4 in nz as my dd and i fill up and reset my odo each time its costing me $100 nzd to fill (40-45L) of bp98 and im getting about 280kms from a tank is this right?

 

Yo need to do a boost leak test, to see if u have a leak somewhere

 

Don't vent the BOV if it's on stock tune. I had it vented for about 1 hour of moderate driving and fuel efficiency plummeted. Also Replace your wastegate with a Kinugawa stock replacement for a evo 8, should get you boosting right again.

I get ~500km motorway driving off a tank in my 6.