Need a bit of advice to fuel consumption..

[munted]

Hi guys,

i've noticed lately that my car seems to be using a lot more petrol than usual...

my current mods are; turbo back exhaust, fmic, apexi avc-r, and 18's... ive noticed it more after having the boost controller installed, which is the most latest mod ive done to my s15.

ive been given various reasons as to why, some are that i need a new ecu or some sort of engine management system, or maybe that i need a new fuel pump or that my car needs a good tune.

any comments or sugestions are appreciated..

thanks in advance guys

 

[Nicely]

What boost are you running?

Main causes for a sudden increase in fuel consumption is a boost leak somewhere or the air flow reading being stuffed-up somehow. Yes, upping the boost will have an effect, but only if its quite a bit more.

Check all the clamps are tight on the IC circuit.

Give the air flow meter filament a clean with brake cleaner.

Get your Lamda sensor checked-out.

Also, believe it or not, the type of fuel you use. If you are still using 95RON, try changing to 97/8RON.

Oh, and welcome :wave:

 

[Vandal]

Have you checked the plugs recently?

 

[Ansch]

I think first of all, do you know exactly how much more fuel the car is using? eg. L/100km. My car does around 11L/100km depending on how heavy my right foot is. a tune eg. remap or power fc will give better fuel consumption because the std ecu will run quite rich on the mods you have so far.

 

[S15R]

fuel consumption = driving style

 

[Nicely]

Yeah, but guys, his driving style isn't going to suddenly change to the degree that its going to affect the economy that much. Its not been happening all the time. Its just started.

 

[Ansch]

oh yes it might... :nod: I notice that when ever I do a mod eg. EBC, I tend to drive the car harder to "test" out the new mod and fuel consumption goes down the drain.

But I think it's a good idea to monitor your fuel consumption at each fill up because you know how hard you drove on the last tank but if all of a sudden consumption goes up without any major reason then you know something is not right.

 

[Nicely]

My fuel consumption has been 24-27mpg (about 10.5-11.5 L/100Km) for quite a while. It was 26mpg (10.8 L/100Km) last week, and that included the 200 mile round trip to and from Silverstone for D1, when much of the journey was at 100mph (160kph). My consumption hardly varies much regardless of how I drive. The only time it really dips is on track days.

I agree though that you need to ACCURATELY monitor fuel consumption to get a good idea if you have a problem. To say you are only getting x miles or Km to a tank is not very accurate...

 

[Ansch]

I'm actually still quite impressed at how fuel efficient the s15's are. For the power that they put out and even with basic mods the fuel consumption stays reasonable... as oppose to cars like the RX8's which are big drinkers

 

[S15R]

never liked rx 8 lol

 

[Topper]

The rotary engine also drink Oil :nod:

My fuel consumption has gone down a fair bit one i fitted my boost controller & atmospheric Bov :nod:

 

[silviac]

i was shocked by last fuel economy.
i normally go around 9.5km/L but my last tank showed me only 8.7km/L
I didn't do anything special but the only thing changed was tank lasted 3 weeks instead of 2 weeks.
Did some of my petrol vaporate or something???

 

[Nicely]

Its possible that some could evaporate in hot conditions, when the cap releases pressure. Not that much though. Its possible that octane degradation occured. Higher octane fuels, particularly Optimax will degrade over a surprisingly short period. A drop in octane rating can cause worse fuel consumption. Obviously, using the air con quite a bit also has an effect.

 

[S15R]

try fill it up at a busy station, higher octane tend to decrease in octane quickly

also dont leave a full tank of fuel but not using it

 

[Topper]

.............also dont leave a full tank of fuel but not using it

My car has been sitting for 2 weeks now with almost a full tank

 

[I-nearly-bought-a-batty]

my car's a guzzler. I've just learnt to live with it

Nicely, I still have no idea how you get the milage you do with the power I have.

I get three sessions to a tank at the track (100ks odd). This guy in 20B NA batmobile uses 60 litres a session. His plate is "FURSTY". I felt better after hearing that :thumbs:

 

[Nicely]

I don't do loads of urban driving to start with. About 5-10 minutes in a average 45-50 minute journey. Another reason is that I've had a remap for the power.. So althought the map isn't up to date, its a hell of a lot better than standard.

 

[I-nearly-bought-a-batty]

ahh - long distance driving - gotcha.

I recalled you saying a few months back when I joined that you got better economy on the track than I got on the road

That's been reverberating in my head ever since

I trust you get better than 100k's per tank at the track :wave:

On my second outing - my tank ran so low on my third session I had to drive miss Daisy for the last 3-4 laps. Everyone must have thought I was a chicken sh1t driver

 

[Nicely]

I trust you get better than 100k's per tank at the track :wave:

I'll let you know in August when I've got a full day at Castle Combe