lousy fuel economy

[pjsupervt]

Hi all,
first time poster here, I'm hoping you guys are as helpful as other forums I've been on.

I have a vt, supercharged S that has for the last year? been getting really bad fuel economy and I can't figure it out. The car runs well, it's not smokey. It doesn't smell of petrol (no leaks?), I had it put on an analyser but that showed nothing. I keep my tyre pressures up to at least 36psi, I've run fuel doctor through it to make sure the injectors are clean. I'm really frustrated!

Anybody out there got suggestions on where to look?

Thanks in advance,

PJ

[CHARGEDVT]

whats your definition of lousy fuel economy? and what type of driving do you do? and what type of petrol do you use?

[pablo]

G'day PJ, Well, you had better give us lot a hint at what the consumption is, and under what driving conditions.

[pjsupervt]

Hi all, most of the driving is city and my wife does most of it as I'm usually in the Patrol. So it is not driven hard, school runs and to the shops, that sort of thing. At the moment I'd be happy to get 400 k's from a tank. My wife drove it for around 60 ks today and that used nearly 1/4 tank. Not sure what the L/100k is but I'm sure its bad. Usually just use regular unleaded.

Thanks,
PJ.

[88GreenVN]

I'd start with O2 sensors and maybe the temp sensor.

If the ECU thinks the engine is cold it pumps in extra fuel.

[vt_II_senator_sig]

Im sure the specifications with the Eaton Supercharged v6 says only to use Premium Unleaded.
Im not sure about the v6 but in a ls1 If the knock sensor is detecting pinging it will de-tune the engine so no damage is done, in turn you use more petrol trying to accelerate like normal.
but if you are using say 15l for 60ks then you are getting around 25l/100ks which is extremely rich... your mechanic should be able to tell you whats going on under the bonnet.

[VryNeat]

mate id be happy for that much off a tank i wasted a quarter tank in a half hour :/ back streets of course but now im taking it nice n shes doing better but still id be happy with that economy

[howepower]

try looking for a vacume leak as the anyliser has good numbers or lean when the engine is drawing air after the maf sensor has calculated air volume

[fitz_vt]

mate you have a SUPERCHARGED S V6 ......
your gonna get lousy fuel economy is u use regular petol........
try a tank of premium and see how she runs

[blwnvt]

out off the factory they got quated at i think 14.2 per 100kms with 98 and u should only use 98 in the l67 with a gold 98 memcal and k & n high flow filter im down to 12.2 on average...