Audi A4 Avant 2.8 quattro - converted to LPG

**Leoness** · 04-05-2007,10:08 PM

Ok so I wanna buy this car as I am hoping the LPG will give me more economical driving.
I would like your advice please.
Is there anything I should know?

**Leoness** · 05-05-2007,08:27 AM

Come on then any one feeling helpful???

**buster** · 09-05-2007,10:09 AM

Originally Posted by Leoness

Ok so I wanna buy this car as I am hoping the LPG will give me more economical driving.
I would like your advice please.
Is there anything I should know?

My 2.7T A6, tiptronic quattro does an average of 26.4 mpg on petrol at a cost of just over 16p per mile. (at 93.9 p litre)

On LPG it does an average of 19mpg at a cost of 9.6p per mile at 39.9 p litre.

However, make sure it works ok with the conversion.

Make sure it starts from cold and changes over to LPG on its own, make sure you can boot it on an uphill incline and it doesn't missfire, make sure it has a certificate from the lpga, and make sure the registration document states it runs on gas.

Mine runs like a dream, but I have seen lpg cars with major problems.

To get 9.6p mile on 93.9p/L it would have to do just over 44 mpg.

The 2.8 should run even better as gas prefers high compression engines like yours and it shpould do more to the gallon. My old 2.8 A4 used to average 33mpg on petrol

**Leoness** · 09-05-2007,10:28 AM

That sounds like good news then, Thanks Buster.

**Singlespeed** · 09-05-2007,10:30 AM

If you ever feel the need...You won't be allowed on Euro tunnel with a gas powered car.

Check the condition of the engine oil. I have had 2 LPG cars, both suffered from emulsion build up in the oil. Caused by running slightly cooler than when on petrol.

**buster** · 09-05-2007,10:37 AM

Originally Posted by Singlespeed

If you ever feel the need...You won't be allowed on Euro tunnel with a gas powered car.

oohh good point, I forgot about that.

Good idea to have a surf around and get some more info too.

These are the guys who did my conversion www.greenfuel.org.uk

Bear in mind they will be biased though LOL

**Leoness** · 09-05-2007,10:46 AM

Funny you should say that we wanted to go on the tunnel to France in September and my Mum pointed this out. It's not the end of the world for us as we have a baby and if the sea's not too choppy it might be better to get him out of his car seat on the ferry for a bit.

With regards to the oil - should I get it checked/ changed more often than the annual service? Or is there a 'thinner' oil that won't be as affected by the cooler running temperature?

I've been on the lpg forum a bit tried to get up to speed with LPG. I think it's essential that the Bigas system is tuned by the right technician to get the best out of it.

Thx guys

**jp_paul** · 09-05-2007,06:39 PM

Originally Posted by Singlespeed

Check the condition of the engine oil. I have had 2 LPG cars, both suffered from emulsion build up in the oil. Caused by running slightly cooler than when on petrol.

I always use a semi-synthetic oil, dropped every 6k miles and it comes out golden in colour, almost like new. This is due to lpg having no additives (potassium, sodium and phosphorus) to care for your engine and valve seats so the oil doesn't get stained by them. However, it still requires changing because it simply isn't as good at removing heat and lubricating as before. Leaving it in will cause it to emulsify, just like it would if you never changed the oil in a petrol engine. So the fact that lpg burns at 1990 degC rather than the mighty 2030 degC developed by petrol is not a reason to cast any doubt on a fuel with 20% CO2 savings and is simply twoddle.

Jp

**Singlespeed** · 09-05-2007,07:37 PM

Originally Posted by jp_paul

I always use a semi-synthetic oil, dropped every 6k miles and it comes out golden in colour, almost like new. This is due to lpg having no additives (potassium, sodium and phosphorus) to care for your engine and valve seats so the oil doesn't get stained by them. However, it still requires changing because it simply isn't as good at removing heat and lubricating as before. Leaving it in will cause it to emulsify, just like it would if you never changed the oil in a petrol engine. So the fact that lpg burns at 1990 degC rather than the mighty 2030 degC developed by petrol is not a reason to cast any doubt on a fuel with 20% CO2 savings and is simply twoddle.

Jp

To be fair, both mine were Astras with factory fit systems and oil changes caried out at 8K. The emulsion cleared when run on petrol for a couple of weeks. The setting up of the LPG system probably left a lot to be desired, when asking about the mayonaise in the oil filler cap, the answer of 'They all do that sir' probably meant that they couldn't be ***** to set it up properly.

The cost savings of LPG will more than cover more frequent oil changes if required. Just that I hated the cars and therefore wouldn't treat them to any compassion.