Diesel, petrol or GAS?

loubee_3

I bought a new Volvo V40 1.8 Bifuel in 2003
Got a discount from Volvo for being a Member of the Institute of Advanced Motorists
and a grant from HM Gov for buying an alternative fuel car.
Plan to run it into the ground -
my last Volvo did a quarter of a million miles.

Think the grant may have been phased out.

Cheaper to tax and fantastic smugness when I fill up for a tenner!

Sure that that Vauxhall do a range called dual fuel.

landy_nuts

I have been running my 3.9 Discovery on LPG for over two years and it is GREAT. So far this year I have saved over £2000 :j compared with running on petrol having covered just under 10K miles. Don't think about it do it. To find an approved instaler try https://www.go-autogas.com

abomb1969

The key to a gas conversion is to pick a big inefficient engine, and my 4.6 litre Range Rover is the perfect example of a huge comfortable car that does the same MPG on gas as petrol. I also had a Volvo S80 2.4 litre on gas and there was no difference in MPG. Pick up a cheap reliable big engined car and convert that, or preferable buy one already converted although thoroughly road test it to make sure the gas system works and dont expect more than 200 miles on a tank of gas if its mounted in the spare wheel well. You will save on the purchase price of the big car which will be excellent value for money.

That said you can get an lpg conversion for a Smart car.

Cardew

abomb1969 wrote:

my 4.6 litre Range Rover is the perfect example of a huge comfortable car that does the same MPG on gas as petrol.

There is no doubt that running costs with LPG are lower than petrol - at current prices.

However LPG has a lower calorific value than petrol and it is difficult to see how it could possibly give the same MPG.

Every independent test I have read unequivocally states that the MPG on LPG is considerably lower than petrol.

abomb1969

Ok so there might be a little in it, but my Rangie is so inefficient/thirsty (9mpg - 15mpg) a 10-20% loss is neglible, and I think its far less than this. Also my system is a direct injection (SGI) system rather than an "open loop" which dumps fuel just after the air intake and is less efficient. I can live with 40mpg equivalent out of my Rangie on 30p/ltr at 15mpg which is my usual mpg. Mind you the downside is the lack of range of any lpg car, whilst the local supplier might be 30p/l its much more expensive elsewhere and inevitably you run out of gas at the expensive garage not the cheap one or you are filling up every day! A bit different to my TDi which went 600 miles between fills - so to keep topped up on cheap gas (30p/l) I reckon I fillup 4-5 times more often than I did on diesel!

I had a TDi and ran that on veg oil without declaring myself to customs&excise which was incredibly good on mpg equivalent - 100mpg equivalent on 90% veg/derv at 40p a litre from Costco. I think that c&e will only register you if you are producing biodiesel and straight veg oil is not recognised by them.

I note your comment about lpg current prices, I think there is another 18 months protection from duty increase more tham 1p a year, but one of my local suppliers has been edging his prices up for lpg and the others must be following suite soon. I thnk the main danger to lpg in cars is a lack of tank size at garages, I have noticed over the last few years that 1 in 3 garages has run out and as more people convert the problem will get worse, its a right pain when you pull into a garage queue up for an age and then find the tanks are empty.

I should probably buy an Audi A2 tdi and run it on straight veg oil (30,000 miles a year you see) which would give me 120mpg in the summer and veg oil will not go up in price like derv thats for sure. But I like the size of my rangie and 4x4 is essential for towing on wet grass.

BG_Porgy

with the difference in the cost of diesel over petrol increasing, the benefit of additional MPG with diesel is eroded. Has anyone out there done the sums to see which is now best at pence per mile?

OK , I know that it varies from car to car but a rule of thumb would be interesting and it is far too late for my brain to work it out

Thanks to anyone who replies
BGPorgy

Slaphappychappy

I've had my factory built Vauxhall Astra 1.6 16v LPG for about 4 1/2 years now and as much as I'd like a new car I really can't justify changing the car without going to another LPG car. When I first got the car it was difficult to find places that actually sold LPG so I mainly ended up in haulage company depots but now there seems to be LPG service stations everywhere, and at an Average price of aroung 40p/Ltr in in the south it's well over half the price of unleaded. When I fill up It costs me just under £19 and I get just over 320 miles on that and I wouldn't say I drive at fuel efficient speeds if you know what I mean. Also considering that the road tax is the lowest band for being a cleaner fuel and If I go into London the car is exempt the congestion charge, I don't think its a bad deal. Only downsides are the extra cost for LPG services and a very slight loss in accelaration. I know people will comment that the tax on LPG (has been frozen for a few years) will be put up but my feeling is that they froze the tax to encourage use of cleaner fuels (G8 summit and all that) so if they put the tax up on it they will show their commitment is not there to cut pollution.

As far as I know, VW and Skoda also do factory fit LPG cars in their range and I'm sure there are others out there.

This is the site I found the most usefull when researching lpg and they have a good section with the location of all the places that sell LPG:
http://www.lpga.co.uk/LPGA.htm

alanbradley

HI...

I've just been reading through this thread and there are a couple of things that maybe I can clear up as I used to sell LPG and took some time looking into all of the possibilities.

1. You can't run a diesel car on lpg - it has to be cng (standing for Compressed Natural Gas or "town gas") that's used instead. Its far harder to get hold of than lpg and is/was mainly used by companies with large fleets of trucks - I believe Tesco (?) ran a fleet of CNG trucks.

2. Unless it was a developmental engine I doubt it was a Subaru engine in the 356 - as far as I know they've not made a diesel engine...

3.The Person with the diesel Corolla may want to ask about on https://www.toyotaownersclub.com/forums for advice on converting to vegetable oil. This seems to be moderately popular in the states atm so you may want to try a couple of web searches. That said they (Americans) only seem to do it to VWs (the only diesel thing they can get...). https://www.tdiclub.com may help...

Umm, yeah. I think that's all.

Personally, I drive a Yaris d-4d and as I can get over 60 to the gallon without trying (and with a lead foot) I don't think its worth me considering any of these conversions. That said, I would use bio-diesel if I could

Cheers,

Alan

PS Wow... Long first post!

PPS If I'm wrong then feel free to correct me...

landy_nuts

Hi
Alan I must disagree you can run cars and trucks on LPG I have seen both in action, in fact an HGV pulled up behind me yesterday as I filled up at my local Calor gas site.
A friend of mine runs a VW camper on diesel / LPG with great affect.

gazza099_2

please excuse me for throwing a spanner in the works!!!!
but i spoke to customs and excise and if you put the oil straight into the tank as (as i was going to do) as apposed to having a two tank system then you are making a diesel substitute which means you should pay about 0.47 pence per litre,
please feel free to check this out your selves