Lpg?

[IT]

LPG is good for high mileage motorway cruising where cruise can press the pedal a little harder on your behalf to make up for the slight loss in power on LPG. On lots of long runs, it does save money, and on long runs you get to know where the stations are and it becomes second nature.

LPG is not good for pootling about, or trying to get high performance out of your motor. Its not good for random adhoc journeys as that will make it harder for the novice to get to grips with the LPG stations and different fitments.

I can see why amar has a tarnished view of LPG, but if he had to do 30K + a year on the roads, he'd quickly see the benefits rack up like some of others have...

It has more subtle benefits too like being able to get your car through an MOT emmisions test no matter what you've done to your cats etc...

[richyb66]

Not strictly A8 related but bear with me. I've got lpg on my 2000 S6 and I'm very pleased with it so far. Due to the mileage I do I was after an lpg car and was looking at and S8 or and S6 that was already converted, I did consider Singhs S8 at the time but was having some issues with insurance due to it being modified so in the end I got an S6 Avant.

I do 70 miles a day travelling to work and then another 300 every weekend going from the Midlands to North Wales where I live at the weekend so probably 650+ miles a week. My only minor gripes are the tank is 70 litre but will actually only hold around 52 litres (80% capacity max to allow for gas expansion), I can do about 200 miles normally or up to 220 if I take it really easy before I need to fill up again. As others have said, the gauge is pretty useless but at least if the gas runs out it switches over to petrol automatically so it's not a major issue. The DIS shows just over 24mpg average overall and I can get up to 27mpg if I drive with a feather foot on my commute to work (mostly motorway).

The other issue is the location of fuel stations - I've got some of the sat nav downloads but they temd not to be that up to date so I don't rely on them. As most of my driving is the same journeys, I tend to use about 4 regular places depending on where I am. I plan ahead to make sure I have fuel before a long trip up to Wales, filling up before I start and then I fill it again up there before returning to the Midlands which will also get me to work and back on a Monday. This is now a regular routine, with me putting gas in pretty well every 2-3 days but I'm used to it now.

I tend not to thing about the equivalent petrol mileage but when I was doing the same journeys in a 1.9 td VW T4 van (that was doing 38mpg), my fuel bill was about the same.

For me the benefits more than outweigh any extra inconvenience - my fuel bill is still pretty colossal but I'm doing over 30k miles a year and this is my only car so there's no way I could afford to do this if I was putting in super unleaded.

The system on my car is Bigas, made in Italy like most of them seem to be. The system could probably do with a service which I'll get done soon - everything else on the car I'll do myself - until it needs a cambelt lol. It's got an ITG filter (the original airbox had to go to make way for the lpg vapouriser) and it's got a go faster stainless exhaust just to make it sound a bit better - no point in having a V8 if you can't hear it.

Great forum btw - some very useful information on here that still applicable to me. Would a Revo remap be worth me considering?

[IT]

Thanks for input, which given you're running the same block and electronics as most of us, is quite valid.

I had exactly the same with LPG, a regular route and knew where to get the fuel so all was well. Filled up at the top of the M1 to get there, and filled up at the bottom of the M1 to get home. Easy.

One slight difference between the D2 A8 and the C5 A6 is that you could have chosen a diesel, these guys cannot. Audi UK in their wisdom only brought petrol varients into the UK, so if you want to drive an A8 pre 2004, you get petrol. Hence why LPG is so prominent amongst A8 owners.

The fact that you had a choice to get diesel, and went for an S6 anyway makes you probably an even bigger petrolhead...

I cant comment professionally on the remaps, but I think with LPG its more complicated as you can only have 1 map, but you have 2 fuels, requiring 2 'optimal' settings. If you optimise it say for economy on LPG, then it might be pants on petrol.... Maybe Ben or Mike will comment.

[richyb66]

Yes, I suppose a remap would only apply to the petrol ECU, but I suppose this would be like having cake and eating it. I could keep the current map for lpg and have more performance orientated map for the occasional "play" on petrol.

I think the Bigas system is actually mapable and at the moment it's set in a more economy mode but can be mapped for more performance so there may be scope there but to be honest it's probably already quick enough, it's not like I'm doing trackdays in it and even on lpg the performance is pretty impressive.

The only other thing I forgot to mention is the smug factor when you're filling up at £0.72 a litre and see someone alongside paying £1.40

[FireStorm]

bumpski

[A8 Doc]

Wahey an LPG thread

Background - Running the stuff for 6 years now on around 12 different cars. So feel I have a good comment on it.

Biggest downside for me is the range of the tank.... 260miles really give or take. But it gets you down the country one way!

The biggest problem in LPG is the variety of systems out there. Most these days are sequential. So they take the output from the petrol injector, apply a conversion figure and inject the equivilent of gas into the car. If the ECU requests more from the petrol injector, the gas injector also allows more gas into the engine. And vice versa.

I firmly believe there are only 2 contenders in the LPG field. BRC and Prins. I've had most of the others including Stag, Bigas, Romano, Zavoli, Landi-Renzo and (Spit) Stargas.

The cars I have these fitted to are A8 (D2), A8 (D3), Range Rover 4.6, BMW 745i, Range Rover L322 4.4 V8, Jaguar XJR, Mercedes CL600...

The A8's wise, I had a D2 running a Romano kit. In all honesty if worked and ran. Fine for high miles, but could not supply gas at higher RPM and switched over harshly. At over £2k installed, it was poor in my opinion.

My first A8 2003 had a 2006 BRC kit on it. It was fantastic. That car covered 40k+ miles on the kit and didn't have one fault. There was no loss of power, the switchover to LPG was undetectable and the system was reliable. I loved this car....

My 2nd A8 2003 model had a Prins system. Equally as good as the one above! Sadly written off.... No issues with the gas system when heavily rear ended. Everything did as it should.

My 3rd A8 2003 model had the Landi Renzo system on it. Fitting was ok, but the kit was no where near the quality of the above 2 contenders. It ran fine, I had a good few miles under the old girl but it was just not as good.

My current car is a late Range Rover L322 4.4 Vogue SE with the BRC kit (Newer version) and it is just as good as the first kit. Very very impressed.

LPG, it's cheap in refuelling. It can be seamless between petrol and gas and you cannot tell, but the installer needs to understand the best places to tap into the coolant systems as well the wiring.

Only go with one who is LPGA certified. They meet certain standards (And you can tell). Nathan's one above is clearly certified as is the ones who have done my RR and A8. Everything looks OEM and is tidy. All holes drilled are smoothed and have rubber linings to avoid chaffing of wires. All wires are soldered and heatshrunk to avoid moisture getting in.... Etc. etc...

Anyway, it isn't cheap. But the thirstier the car, the quicker the payback. I'm still running LPG now and had the Rangie converted, worth every penny