Crap fuel economy. Tried everything... What else?

[LGberlina]

Mate I get an average of 12.8 in my gen3 around town. thats with an exhaust upgrade. Adelaide to Broken Hill I avg. 9.8. your cars not well.

 

[wrx884]

from all the other fuel burn threads around here, about 400-450 ks is about average for an ecotec or any model, vs-vy. i only usually get about 459 outta mine

u have 2 remember the VT/VX's have bigger tanks so i dont think u can compare them on avg with lower model ecotecs i would say avg would b more close 2 the 500-550 (city driving) mark in a VT/VX model wat u said would b more so with the lower models

 

[Tree cutter]

Have you tried using a different brand of fuel. I have found that some of the discount fuels from the supermarkets give you crap fuel economy and quite a few other people on different forums notice the same. I seem to get better fuel economy with BP fuel in my Calais and noticed the same with my VL that only needed normal unleaded. My cars seem to drink more fuel when i use the woolworths fuel and the shell fuel is about in the middle of the two for economy.

 

[mattman]

Keep in mind that some BP's run ethanol in 91 now (look for it marked at the pump). I know of only one in qld, a brand newie, all the others still seem to run ethanol free.

I went to "Matilda" station last week, put their 95 in... towards the end of the week was running rougher and harder to start. Refilled with BP 95 today, trip down to seaworld and back and all is sweet again... remind me not to go to Matilda again :s as a bonus avg is down to 14/100 (didn't reset).

 

[nunny]

I mostly drive short distances say 8 - 20kms at a time with a longer drive say 90km on someweekends. I get about 450kms for this mostly city driving which I thought was pretty lousy. I recently drove Brisbane to Melbourne, mostly highway and got close to 600km out of a tank. I think the stop start driving and low average overall speeds really make for lousy fuel economy.
VT Calais Ecotec.

 

[Troy]

Just using ordinary 91 Unleaded. No need in my view for higher octane fuel.

Try using premium over the course of about 10 tanks and see if there is any difference, there are detergents in premium that arn't found in regular that'll keep you fuel system (ie: filter, lines, injectors, pump-filter) cleaner for a lot longer. What have you got to loose?

You say you shouldn't have to look at your throttle body and IAC valve, you already stated you very particular about things, have a look and you'll be suprised just how much crap can build up on it. Every little bit helps, again, what have you got to loose?

If you want to see a mess of sludge that'll make you cry, lift the lid on your plenum chamber and look at all the black, hard, burnt oil that's in there that's come out of the PCV valve. It can be cleaned off with a bit of patience.

One last thing, are you driving around with the air-con on? If yes, try turning it off and see what difference there is.