Thread: What kind of range should a 3.9v8 be getting on LPG? (mine may have problems)

That's about what I get on the hwy. Usualy get around 33l per 100km combind hwy and low range driving when out for the day. Gives me a range of 150 to 170 out of 55L. It's lucky I still have the full size petrol tank to give me some range. I run 31" tyres and have a bit of bar work front and rear and roof racks putting a bit of weight on. It's a good thing it's not my everyday driver.

hey mate i have a 94 series 1 3.9 on gas too, i have a 45 litre tank and on highway i get 400 k's havent really tested out the fuel cause the gas is too cheap at moment. you have got a similar set up to me under the hood but i have a defender air intake not the rectangle one you have.

I have a 96 v8 5spd with the twin tanks in place of the fuel tank and i get 400k's.
my under hood setup is the same as yours.

So something isn't quite right. Would the advanced timing have anything to do with it? (10 deg BTDC)

I have a 60 lt tank and after a year of running it in the city and in heavy hills in a 94 disco with a 4.6 in it with an auto gearbox I get 250km per tank.

Having said that Busy Bee just tuned it for me after I had it done at a "reputable" landrover specialist about 4 months ago, the difference is spectacular so I will have to do it again to see what it is now.

My advise is ring around and find a LPG service specialist because if you have had the timing set back to 'standard' by the people who last did it for you, then they don't know what they are doing when it comes to LPG

Well I can set the timing myself if need be but from everyone's findings it sounds like my LPG economy should be a fair bit better than what it is currently. I just filled up for the first time today after having it tuned and I got 220km out of 65 litres...from what I've heard everyone else gets that sounds like pretty rubbish economy.

The place that tuned it claims to be LPG specialists, and a dedicated Land Rover place to boot (Range Rover Automotive in Vermont) so I don't see why they wouldn't have it all under control but surely there must be more to it than that, even without going all out with a dyno tune and oxy sensors or whatever else I've heard people doing.

Any suggestions for LPG specialists who people have had good economy results from after a tune?

Hey why don't you try adjusting it yourself. The main mixture is on the mixer right by the 1 inch gas inlet hose. Look carefully and you will see L and R marks. Move the adjuster 1 notch towards the L and try again.

I take it L is for lean and R for rich?