LPG update, mpg figures

[badger]

Well, after my recent LPG conversion on the Hemi
(see LPG conversion on 5.7 Hemi )
I thought I'd post my findings regarding mpg now that I've done a few miles.

Local driving, lots of cold starts,
Petrol :- 18.5 mpg
LPG :- 16.0 mpg (86.5% of petrol figure)

Longish run at steady 50-60mph with 2 towns to go through (stop/start)
Petrol :- 26.8 mpg
LPG :- 22.8 mpg (85% of petrol figure)

These figures were achieved during fairly steady and sedate driving with no violent or hard accelerations (well, bar the convoy of 3 lorries that I overtook on the way back from Inverness, I couldn't resist, lol) and with a lot of cold starts for the local figures, but already warmed up for the longish run figures.

Here's the best bit though - with LPG at 59.9ppl and disiesel at 118.9ppl, LPG is 50.38% cheaper, so if we do a direct "miles per pound" conversion, the "equivalent-to-diesel" figures now become
Local :- 31.76mpg
Run :- 45.25mpg

With the twin LPG tanks holding 17gall usable LPG, that gives me a predicted range (cruise, on gas) of just over 380miles, my aim was to be able to do 340miles without looking for gas.

I am obviously extremely happy with these figures, although they will no doubt reduce slightly given time as the novelty wears off and I stop watching the mpg display in the EVIC. Having said that, I feel there is every chance of an even better cruise figure when going a longer distance without having to slow down to go through any towns!

to diesel,
to Gordon Clown,
Oy, Chancellor, kiss my hahahahahaha.

[watsonofearnock]

As far as the last sentiment to the Chancellor is concerned I am sure you speak for the vast majority of the British public. The panda should be kept behind bars (and not the ones at Westminster). Good results though but it will take a while to overtake the installation costs - even for you DIYing it.
Cheers John

[badger]

John, assuming an average of 20 mpg on petrol at £1.15 per litre over the year and 10,000 miles, cost on petrol would be £2610.
Same miles but at the LPG 85% mpg figure (17mpg) and 60ppl, cost is £1600.
Total fuel saving per annum, £1010. The cost of the kit to me (trade) was £1100, so payback will be 13 months! Even for a customer's vehicle and similar mileage, payback would be around 21 months. Less obviously if the mileage is greater. (18 months at UK average of 12k per annum)

Oh, and all mpg figures have been confirmed by brim-to-brim filling, before anyone asks. EVIC figure was proven against actual values on petrol, to prove it read in UK gallons not US ones. (strange that, the U.S. of A. has so much that is bigger than our equivalent - roads, burgers, steaks, cars etc etc - but we have bigger gallons!)

[watsonofearnock]

Did there not used to be a government "bribe" to convert to LPG - does that no longer apply. In my case I will only do about 5 or 6K in the Chrysler per annum (plus 3K in the Stag) so it would never pay me given that I change the car after 3 years But the maths is good and for anyone covering the miles it certainly would be worthwhile looking at.
Cheers John

[devilmaycare]

The problem with government "bribes" - like the £1000 bribe they originally introduced for hybrid cars - is that they are quietly dropped once the take up becomes significant. I fear the same thing will happen with alternative fuel duties and, in fact, the recent budget excise duty changes confirm this policy. Don't forget, the name of the game is to constantly increase overall tax revenues by whatever means are opportune. I sometimes wonder what would happen if everyone drove around in electric cars which were re-charged at home using windmills and/or solar cells. My guess is that road pricing schemes would then be introduced with a vengeance to ensure continuity of tax revenue.

[badger]

devilmaycare, I fear you have hit the proverbial nail on the head! I've been running vehicles on LPG now for more years than I care to remember, but it's allowed me to stay one step ahead of the game. People who all said to me 7 or so years ago "but the duty will go up then I won't make the savings" have all been proved wrong, and had they converted then, they'd be quids in by now. In most cases it's fear of the unknown that prevents people converting, and whilst it's the nature of my business (and a personal necessity) to make profit, it suits me just fine that the uptake of LPG has been slow in this country, as that allows those that have commited to it to reap in the financial benefits.
John, there was a grant scheme called "Powershift" once upon a time, but the muppets in power/london only put in a certain ammount of money and when the pot was empty, that was that. They also ensured that it was only modern, already efficient and lower emissions vehicles (by virtue of age, not size) that were on the register for grant approval, instead of helping to clean up older vehicles!