My lpg tank takes...
75 Litres per tank (16.5 Gallons) for 200 miles = 12Mpg in my 4.2 '07 L322 FullFat Supercharged. Approx £40 worth.

53p a litre lpg = 53x75 litres= £39.75 per tank = distance 200 miles @ 12mpg
120p a litre petrol = 120x100 litres = £120 per tank = distance 350 miles @ 16 mpg

Its works out for me every 10,000 miles I save £1587 (ref: https://www.drivelpg.co.uk/about-autogas/savings-calculator/) Range Rover Vogue SE 2007 L322 4.2 Supercharged 121k. Engine rebuilt @ 120666 Miles

Wanted to say thanks for the tip about Brisk plugs. We’ve had our 2002 4.4 Range Rover for about 3 months now. Plenty of teething problems sorted by my local indy, and then the CEL and a misfire appeared last week.

I took out all the plugs, it was fitted with bkr6equp multipoint plugs. All looked ok except for the rear plugs on either side that are suffering with oil down the plug holes. The gaskets are a job for next weekend!

I tested the primary and secondary windings on each coil. Easy with a multimeter. Followed the tip on the hella website to test the secondary windings. You have to use a battery in series to test the secondaries. https://www.hella.com/techworld/uk/Technic...coil-2886/

Odd thing was that the 8 on the car were all 0.5-0.6ohms on the primaries but only 10.2v on the secondaries. Whereas some spare used ones off eBay gave the same for the primary windings, but 11.5v for the secondary windings. I wonder if the multipoint plugs put a strain on the coils in the car, which led to them giving trouble?

Anyway a new set of Brisk DR15YS silver single point plugs fitted, gapped to 0.9mm and replaced the coils with some used ones. Just got back from a test drive, the misfire has gone and the CEL is no longer flashing. So thanks once again for the recommendations on this site.

I've read on other LPG specific sites that when gapping the plugs you should set them with a smaller gap for LPG. Has anyone got any experience of this?

I have a Jaguar 4.4 V8 incase it makes any difference

I have jaguar 4.4 ajv8 with lpg, and with original spec ngk plugs (iridium) it works better on lpg, it is much smoother in idle than on petrol. This is with original spark plug gap out of the box, why would it need smaller gap setting? RR HSE 4.4 2006 LPG

As above use the petrol spec iridium plugs and leave the gapas for petrol, no issues whatsoever

maric995 wrote:

I have jaguar 4.4 ajv8 with lpg, and with original spec ngk plugs (iridium) it works better on lpg, it is much smoother in idle than on petrol. This is with original spark plug gap out of the box, why would it need smaller gap setting?