First bought this truck about 1 month ago, was averaging around 16L/100km which I thought was kind of strange, I have heard of these trucks being thirsty but this much, nah can't be right. So I fiddled around a little bit and got much help from this site and a few other sites and managed to get my fuel consumption down doing exactly the same amount of city driving, stopping and starting etc. From 16L/100km I am now averaging 13L/100km by doing the following:
1. Cleaned the K&N air filter with the K&N cleaning kit
2. Removed the MAF sensor, cleaned it with Mass Air Flow sensor cleaner
3. Cleaned the throttle bay with throttle bay cleaner
4. Replaced the 02 sensors
5. Replaced the spark plugs to high quality NGK Platinum plugs from sprint auto
6. Removed the rear muffler that had a hole in the joining pipe and replaced with a brand new genuine Holden muffler
7. Replaced the fuel filter
Not only has the trucks performance enhanced significantly but getting much better fuel consumption has made it worth all the work done.
Cheers