I've had my GQ for a month now, and at last all the mods are done and it's ready for its first Grand Adventure in the forests around
Coffs Harbour next week. Until now, it's just been used around town, but I've done some preliminary fuel consumption figures.
It has the 4.2L engine, 5-speed manual box, it's a 12/88 model, and it came with a BRC system with a 90l tank. I have no idea who fitted it, but they seem to have done a very professional job.
I did a measurement a couple of weeks ago and I ended up with a figure of 3.9 km/l. Hmmm. The 60 series LandCruiser I had gave me a consistent 5 to 5.5 km/l on LPG or petrol. I know the Patrol has a bigger engine, but surely 200cc extra can't be responsible for giving me 25% more fuel consumption. I was kind of expecting to get a highway touring range of 400 to 450 km on a tank, but I get the same range as the LandCruiser (300-340km) with 50% more fuel in the back. Not good.
I had a look at the timing, and it was sitting at 15°BTDC at 700RPM. The dwell angle was spot on at 40°. I know the burn characteristics of LPG and petrol are different, but I also remember that I had the LandCruiser tuned to the petrol specs and it ran just fine on either fuel, so I reset the timing on the Patrol to what the petrol specs said, namely 10°TDC at 650RPM.
It's too early to clearly tell what effect this has had, but a first run suggests a figure of only 3.3 km/l. Ooops.
I don't have any consumption figures for petrol running yet as that will show on the trip up north next week, but I've read that you can expect around 4.5 km/l for this engine. It'd be nice if I got that. Time will tell.
So my questions are:
1) What should you expect to see, consumption-wise, for this engine on both fuels?
2) How do you adjust the gas flow rate out of the reducer? I dimly remember when I replaced the Landirenzo gas reducer on the LandCruiser a couple of years ago, the manual said to run the engine to around 3000RPM and then reduce the gas flow adjuster screw until the revs just started to drop, then back off the screw by half a turn. Problem is, I can't find the manual from when I did it the first time, and I'm not sure if that's the right procedure, although it sounds likely.
Apart from the poor fuel consumption, I'm very happy with my "new" GQ. The engine runs like a watch and absolutely trounces over the 60 series I had for power and smooth running. The only thing is it drinks like a V12.