Fuel consumption

I had an FJ62 Sahara on gas/petrol (auto), 350k on it when I sold it. Was getting around 22L per 100k on gas, or 4 to 5 km per litre. It had extractors and 2 1/2 inch exhaust, still not overly powerful but will plug away all day. Was quite reliable.

WYRSS,

I had an FJ62 Sahara on dual fuel for many years and it was one of the best 4by's I've ever had.
I towed a 1500kg trailer every day of my life for work when I had it as I was a builder then. I also had other interests which generally meant I was regularly towing heavy loads such as 2500kg boats, tandem car trailers etc...
I just checked some of my old consumption figures and the worst I ever got either when labouring in heavy sand or towing in the mountains was 25L/100km or in your figures is 3.5km/L. This was when running on gas and was a bit better than this on petrol.
When I first purchased the truck and before I bolted on bullbar, driving lights, roofrack and another 500kg of accessories (140L Gas tank, 125L Fuel Tank, 6/15x11 steel rims with 33x12 tyres etc.) I actually returned some very good figures of 8.5km/L (11.7L/100km). But each time i added more weight or did something that affected aerodynamics the figures dropped to the point where the best I could get when it was empty and on the highway was 6km/L (16.6L/100km).

I agree with you that your consumption figures seem excessive and dual fuel vehicles with a carby are always going to have to be tuned as a compromise on one fuel or the other but I think if you take it to an LPG specialist for a good tune up you should be able to get some better consumption figures than you are currently getting.

Best regards,
Brett

I had a 3F in my 73 series until I converted it to a 1HZ . My fuel comsumption varied from 15-20 litres per 100 klms.

It does not have fast acceleration and extractors are more of a placebo effect in my book.
The engine is based on a 50 year old chev 6 cyl when fuel was 15 cents a gallon in the US.
I would get it looked at by someone who knows about LPG conversions.
The spark from the distributor is naturally weak and some say an aftermarket kit will improve peformance.
My 1HZ conversion cost $9000+ for a rebuilt engine ,gearbox doing much of it myself.
It get about 13 ltres per 100 and will take a long long time to get my money back but I am very happy wih it