The LTD isn't on LPG, It runs 98 only.
I should have said which car I was referring too.

I have an EB XR8, stock throughout with 3.27 gears and Gas Research. I hoped for 400klm with such an expensive system.
It only pinged on Petrol so I cleaned the system out.
Haven't put enough petrol in to see if pinging has gone.
Timing is set to the standard 30.

1991 Ford Fairlane Ghia V8 (302 windsor)
65 Litre LPG Tank

Country trip 426 KM on LPG
Country trip 440 KM on LPG/ Hydrogen

City Driving on LPG 305 KM
City Driving on LPG/hydrogen 3o8.9

City and country driving on petrol
Haven't got a clue, I can't afford petrol.

Doc

gra system,7-8km\ltr and 3.08 diff---cruse 120-130ks,lpg. get your exhaust checked,you may have to re jet vac lines,as to ks\ltr im in hills most of the time and small flats,and a brick foot.