Running on Vapours

[Mostly Harmless]

Hola Everyone! First post so go easy

I run a BMW e39 540i M Sport Touring. I bought it 18 months ago and had it converted fairly soon after. It's a BRC system installed by guys who usually put them in Landys.

System seems to work fine. Occasionally drops back in to petrol when I floor it, but not always.

I decided early on to use pipercross filters and NGK Iridium plugs - So I was interested to read various threads on plug wear. I'll check mine next week and let y'all know.

I wrote an article for the BMW Car Club Magazine, though when it goes in I don't know. April out soon.

I fill with petrol every 3 months and scour the internet for the best LPG prices I could write a very boring thesis on consumption featuring funky excel graphs. Suffice to say I don't take the OBC digital readout as the word of God! My stats measure fill to fill and so are therefore an average of varying road conditions. Worst unsurprisingly was between two filling stations in Northants and would have probably been lower than 12mpg had I not done several laps on petrol

Best was recently getting 25mpg How did I do that?! Must check the odo

My only grumble / wish would be for a larger donut tank it's 70 litres, but it rarely takes 62, usually I bottle after 30 miles of flashing fuel level warning and fill only 55 (which results in say 230mile range). Somebody asked about 540i lpg consumption. I'll try posts a reply with a graph. Oooooh!

Curious now about suggested variations in fuel. I'll check other posts

[Gilbertd]

Variations in fuel usually only apply from one country to the other. Some independent suppliers claim to put additives in their LPG but whether they actually do and whether they have any effect is not really known. The difference between countries is what gas you get when you fill up at the pumps. In the UK, Autogas is 100% Propane. In other countries it is a blend of Propane and Butane. It can be anything from 90% Propane, 10% Butane up to a 50/50 mix. Butane has a lower octane rating than Propane so it has the effect of lowering the overall octane rating from pure Propane which is around 110 octane. I found, and a few other people have noticed the same, that you get better economy with no noticeable reduction in performance on a Propane/Butane mix. In the UK the best I ever got from a tankful (46 litres) on my old Saab was 262 miles except when I drove across Europe where I managed 280 miles.

[tommo2009]

in the UK it is a mix, and the mix changes throughout the year

[richard_ha]

This is a great site for keeping track of consumption figures....
http://www.fuelly.com/driver/richardha/prelude
That is my now written off Prelude.

Going to pick my new car up tomorrow and will start again!

[Ricey155]

Fuelly is a good system, i myself got a bit bored tracking in the end

here's my early LPG use / petrol http://www.fuelly.com/driver/ricey155/civic

in the end i just decided to pick a figure where id break even and go to there, my EP3 is doing between 200 and 220 drive the same all the time, so must be the mix !!

still bloody great even if its 76p a litre massive smile when people rant about how @!## LPG is REALLY

[bmbratz]

How's the Beema goin it's a beast it shouldn't go to petrol if you put your foot
Down what kind or BRC system is it the twin vaporisers I'm running a cayenne on a BRC system