Converting 996 Carrera to LPG - Practicalities NOT Opinions

Hi Here is something that has interested me, from a purely technical point of view. Please do not post comments re: opinion of merit of doing it, or along the lines of "why would you do this to a porsche, buy a smart car if you want economy" etc, I do not intend to do so, just would like to know if it was possible, and if one would get the same/similar performance etc. I contacted a local LPG specialist Envy Motors in Chelsea, London (they are selling the new £100k+ fully electric Range-Rovers http://www.envymotors.co.uk/liberty.html ) to see if it was possible just as an enquiry, they said they had looked at the 996 and decided it was NOT possible, however would not say why. I have since seen on http://911uk.com/viewtopic.php?t=30169&highlight=lpg that there may be a LEGAL issue, not just a practical one, with putting the tank either in place of rear seats, or in the front boot. Does anyone know any hard facts on this, and any effect on performance, I beleive that the MPG decreases a bit, however its so much cheaper that this is negliable? Kind Regards edward

Don't know specifically about a Porsche, but LPG has a lower calorific value than petrol, so will reduce performance slightly and, as you say, have a significant impact on fuel consumption (typically up to 30% worse). Don't know why, but all the LPG convertors that I could find will not quote for a 911... I suspect there is a legal implication of having an LPG tank ahead of the occupants, and it would have to be sealed and vented outside the car if fitted in the rear passenger space (and you can't vent it into the engine compartment for fairly obvious reasons!) In fact, I wonder whether you can have the tank ahead of the engine at all? As it would not be clever to have a gas leak going anywhere near anything hot or with a spark! :?:

Thanks Wattie, anyone else know anymore re: the legal side, and/or any extra technical points?

My brother has just had his Cayenne Turbo converted to gas. It was done by a company called gas4cars in Milton Keynes. The owner is a chap named Stuart Grey, and he owns an early 996. He's a very switched-on bloke, so it might be worth giving him a call. http://www.gas4cars.com HTH

It may simply be a question of space. There may not be enough room to get a tank in to go any distance. Even a big tank doesn't have a great range.

My experience with aftermarket LPG hasn't been good A neighbour had a range rover with LPG, the tank took up all the boot space, I had a BMW 320 with LPG, conversion 2 years old, no instruction book but a sticker with fitters name and no, on contacting him he said it had never worked from day one!!!!!! Eventually cost me £800 to fix after selling it to someone who specifically wanted lpg, having spoken to other chums in the trade, there opinion everytime was if you buy a car with LPG, take it off or dont buy it it only means grief!! Also i'm told that the lack of lead in lpg means you can in some cars burn wear the valve stem seals prematurely and burn the valves out I know some volvos and vauxhals and saabs have it as a factory option, You can get 30mpg on a run withoiut too much trouble on a 996, so why bother, I'd spend the money on a Sports Exhaust, now petrols back to 99p a litre, dont worry and enjoy , porcshe is about enjoyment, they do 30 mpg most are low mileage so were not hurting the planet anyway Am i really on a Porsche forum or is this citroen estate lentil munching sandals.com????????

The baisc numbers do stack up if it works, as saving circa 50p a litre means a potential £1k saving a year on however the engine consquences, car value mean you'll probably loose a lot more as it will be a complex and pricey conversion

Not sure if it helps, but a few years ago I had the chance of doing the Palmer Sport Trackday at the Bedford Autodrome. All their cars ran on LPG including the 996 GT3s! I'm not sure if they still have the cars but it might be worth giving them a call. http://www.palmersport.com/ or Tel: 01403 733999

This is very interesting, I have seen the JP3 GT3's but did not realise they were LPG By chance i have just started reading the November 2008 issue of 911 & Porsche World magazine, page 10 has an article entitled "Porsche Owners turn to LPG", where Stephen Frickers of Gas Power UK states it should be possible to convert a 911 because the front boot is large enough for decent sized tank Still no mention of legalities etc

We were bombarded with calls from LPG conversion companies a few years ago to change our fleet/taxis to LPG. I would of considered it but I didn't see enough people doing it so wondered why :?: :?: anyway we get the red diesel off the Gypsies now :floor: :floor: :floor: