Low Fuel Economy

[Cadmoon]

I get about 450k's or for a real comparison 10L/100k, front mount, 3" turbo back and stocko 5/7 psi boost.

[high_hp]

he guys i did a fuel test with my 33gtr on the m1 i was shocked when i found out im using 1litre of fuel every 5km just normal driving i took it took the gold coast a few weeks ago and got 135km to a full tank that was having a few runs and general driving i do have t88 3 fuel pumps and 4" exhaust

[coaster]

out of my semi stock cars(intercooler, exhaust 12psi) i normally get 10 to 11l per hundred. sometimes even 9 on highways. i had a 350kw one that got only 280- 350km out of around 50-55L depending on driving. That didnt stop me getting a smile on my face every time i drove it

Do a full service, injector cleaner and 02 sensor and see what happens then. A well maintained healty motor stockish car should get to about 10/L

[coaster]

he guys i did a fuel test with my 33gtr on the m1 i was shocked when i found out im using 1litre of fuel every 5km just normal driving i took it took the gold coast a few weeks ago and got 135km to a full tank that was having a few runs and general driving i do have t88 3 fuel pumps and 4" exhaust

id get a new tuner! Unless you were on boost the whole way...

[mad082]

Thought I'd spend the doe and get a compression test done aswell. Booking that in with Pete at rpm.

I'm running 18" wheels with low pros federal/Heros.

I'm thinking it's bc my tank is not 65 ltr as u guys keep saying it is . don't ask why, it was like that when I bought her.

Thanks for the replies, several minds are better than 1 so I thought I'd check.

~ash

I don't run mine down under the E, ever

and that is why saying "a tank" when talking fuel economy is pointless

as for your tank being smaller, is it actually an aftermarket tank, or is it that you've got an aftermarket fuel pump that hasn't been fitted low enough to allow you full use of the tank?

either way, i'm down to halfway in my tank, done over 400kms, trip computer saying about 500kms left till empty, and even then there will still be 10 to 15L left in the tank. but it's a crappy old commodore with a 75L tank.

[high_hp]

id get a new tuner! Unless you were on boost the whole way...

na cant get any better my gtr has 710hp atw with a fully worked rb engine

[116.hks]

Shit dude that's pretty bad. My not be the running of the car, could be something as simple as the sender unit in the tank giving an incorrect reading as well. The wife's 33 doesn't do to bad on fuel considering she only works a short distance from home, usually gets over close to 250k's to half a tank and thats driving back streets. So as you can imagine it's a lot of slow corners and acceleration in short spurts.

While on the subject of fuel economy, took the 32 out to toowoomba the other week, full car, 317kw, and got just under 400km to 3/4 tank. Hasn't been on a desent drive like that before. A few years ago, we use to have some crazy late night runs down the highway towards the NSW border, giving her a really good flog, and made it back to the northside before putting fuel in her. Pete, RPM, really nows how to get the most out of a tune thats for sure.

[skyline32sup]

My old R32 used to get around 300-400 per tank, ran a bit rich but was still pretty shit lol.

[beemae30]

My 32 gets around 500km to the light on highway and around 400 around town. Frontmount, 3" turbo back, 10psi,

[RandomHero83]

Shit dude that's pretty bad. My not be the running of the car, could be something as simple as the sender unit in the tank giving an incorrect reading as well. The wife's 33 doesn't do to bad on fuel considering she only works a short distance from home, usually gets over close to 250k's to half a tank and thats driving back streets. So as you can imagine it's a lot of slow corners and acceleration in short spurts.

While on the subject of fuel economy, took the 32 out to toowoomba the other week, full car, 317kw, and got just under 400km to 3/4 tank. Hasn't been on a desent drive like that before. A few years ago, we use to have some crazy late night runs down the highway towards the NSW border, giving her a really good flog, and made it back to the northside before putting fuel in her. Pete, RPM, really nows how to get the most out of a tune thats for sure.

+1 for Pete @ RPM.

My 34 is 360hp at the wheels and I get about 350k around town ( no highway k's ) to a tank. When I do take it on a long trip I get between 500 and 600k's out of a tank depending on how many people are in the care and if I am just cruising.

[116.hks]

Thats awesome Clint. Good crusier with power to punch.

[510-KAZ]

Thought I'd throw my own experiences in as well, 5 speed R34 GTT sedan getting about 34ok's for a tank of BP 98. Basic mods, cold fed pod filter, 3" turbo back, FMIC, stock ecu, 12psi. Engine and transmission conversion through a number of less than qualified workshops (including 'Nizzpro' when they were at Ashmore). Thought it must have been a wire or 2 not connected as I got the car back and the speedo, air con wasn;t working and was running only 5psi and felt real flat. Turned out was a knock sensor not connected (thanks Chiptorque) Made 164kw and ran a lot better so I thought fuel economy would improve as it was no longer running on a 'safe' tune.

NOPE, 320/340 a tank so no change at all. AFR's continually bounce between 13.5 and 15.8 cruising on the highway (AEM UEGO gauge).

But on a positive some gas rebates still apply and liquid injection technology is getting good gains over petrol.

[89CAL]

Thought I'd throw my own experiences in as well, 5 speed R34 GTT sedan getting about 34ok's for a tank of BP 98. Basic mods, cold fed pod filter, 3" turbo back, FMIC, stock ecu, 12psi. Engine and transmission conversion through a number of less than qualified workshops (including 'Nizzpro' when they were at Ashmore). Thought it must have been a wire or 2 not connected as I got the car back and the speedo, air con wasn;t working and was running only 5psi and felt real flat. Turned out was a knock sensor not connected (thanks Chiptorque) Made 164kw and ran a lot better so I thought fuel economy would improve as it was no longer running on a 'safe' tune.

NOPE, 320/340 a tank so no change at all. AFR's continually bounce between 13.5 and 15.8 cruising on the highway (AEM UEGO gauge).

But on a positive some gas rebates still apply and liquid injection technology is getting good gains over petrol.

I can't see where you listed an after market ecu/piggyback?

But sounds like your map is tuned for fuel economy but o2 feedback is still on if its cycling between lean and rich on constant light throttle

If you still have a stock ecu with no mods I don't see how it is tuned?

[chubs]

my S2 33 gtst was getting 600ks per full tank before the light came on. Mods- 10psi, front mount, 3inch turbo back exhaust and a pod.

Put it in got new timing belt and bearings, and a service and now suddenly im getting 500kms max. Ecu is standard so not sure whats happened that with parts in bad need of replacement i was getting more kms.

[coaster]

wonder if its oil related? did you change your oil brand or type? i couldnt possibly see it having that much of a difference. maybe a bit more stick given to the car once everything is in tip top condition? i always love going for a good drive once iv got everything back in tip top shape!

[chubs]

feels much better yeah. guess could be the power difference

[510-KAZ]

Hey 89CAL, there are no aftermarket/piggy back computers in my car. I meant I had bought a manual 1/2 cut and transferred everything from the cut to my sedan. Computer, some looms, trasmission and so on.

The safe tune I was referring to is similiar to a safe/limp home mode but not as severe. It was caused by the knock sensor not being connected, it really retards the timing and runs on a much more fueled up map.

And I had a quick chat to Lochy at Chiptorque and was suprised the fuel map will cycle back and forth rather than stay as close to 14.7 as conditions allow.

[pipster11]

one thing a lot of people overlook is the coolant temp sensor

i use an ecutalk display so i can see whats going on and it gives l/100km too (you just input your injector size and it works it out)

best i've ever seen in the stagea was 9.6 l/100km driving from melb to qld, i think that tank was v-power actually

around the town sees 12-14 so if i can get that fuel consumption in a 1650kg wagon then others should be able to get the same or better from a 1500kg whale

oh, and the guy that has the t88 gtr, i'd get your tuner to tune for low throttle input cos that fuel useage is retarded, unless you were on boost the whole way

[89CAL]

Hey 89CAL, there are no aftermarket/piggy back computers in my car. I meant I had bought a manual 1/2 cut and transferred everything from the cut to my sedan. Computer, some looms, trasmission and so on.

The safe tune I was referring to is similiar to a safe/limp home mode but not as severe. It was caused by the knock sensor not being connected, it really retards the timing and runs on a much more fueled up map.

And I had a quick chat to Lochy at Chiptorque and was suprised the fuel map will cycle back and forth rather than stay as close to 14.7 as conditions allow.

ah ok i get it now

sounds like similar situaton to what happens when you set your target AFR higher then what the narrowband can read and it dumps more fuel in to bring it back within range then starts over again. This is with Power FC, when I had o2 feedback on. It wasnt a problem as soon as i turned o2 feedback off, just have to tune the target AFR's

[mad082]

i recently changed the wheels on my vt commodore from the 18's it had on it when i bought it to a set of 15's i had sitting around (hit a rock on the highway and damaged a rim and tyre, so just bought new 15's instead of new 18's and getting the rim fixed). anywho, going from the 18's with 235 tyres to 15's running 205 tyres has knocked about 0.5L/100kms off my fuel usage. i'm now down to under 8.5L/100kms