PerthGQ replied:

MightyQ,
My thought is that it's relative to the engine size and what you're currently getting as against what you would like to achieve. I have a '96 4.2EFI LWB auto and get 17L/100km around town, and around 14-15L/100km on a country run, sometimes a little better. I dont think about economy when in the soft stuff etc. I'm reasonably happy with the economy but considering putting extractors on along with a K&N air filter as these appear to be the two changes that will give the biggest changes (I hope!). At the end of the day it's the money you spend against the period it will take to recoup it in saved fuel, unless you're spending to buy more power.
Keith

Truckster (Vic) replied:

You can search the archives, there was a thread I started with about 20 replys from GQ owners on fuel economy.

20-25l/100klms in a TB42 Non EFI GQ is common.
Diesel TD42 you can get 14/100klms

You have disgarded the gas and your fuel econ has improved?

Paul1 replied:

MightyQ
I have been through the same issue recently. We are planning a major trip next year taking a few months and covering lots of ks, but when I did a petrol costing against costs of selling and buying a diesel or looking for ways of squeezing a few extra ks per litre I realized it wasn't worth the effort. In the end it was an extra $300 for fuel. It wasn't worth the change over to another vehicle. Transfer costs alone are equal to that. Extractors are a couple of hundred dollars fitted. Hiclone, well I won't go there. Its been done before and costs $180. I have fitted a K&N filter and found a significant improvement in torque, but not in fuel savings.

Estimate your annual ks. Calculate your fuel bill. What realistic fuel consumption do you think you could get and compare the possible savings against expenditure in achieving it. There are a lot of threads about the quality of fuel from different suppliers. You can improve your consumption by choosing your supplier. Discount petrol vs Shell Optimax etc.

If you find the secret to better consumption be sure to post it here for all to read.

Take care
Paul

Rossco100series replied:

Extractors and a good exhaust, K&N filter or a Uni filter, electronic ignition will all help but depends on how far you want 2 go. Like taking off the engine fan and going to a thermo fan ( electric ) and now you can also get electric water pumps ( Davies Graig ) and making the mechanical pump non functional and even full synthetic oil ( Mobil 1 or Shell Helix Ultra ). And a Hiclone well um yeh didnt work for me but I do know of a couple people that it did work for, so try it if it makes a difference great if not get your money back.

Have fun