BMW 325i LPG

BMW 325i LPG

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325iMSport

Original Poster:

326 posts

174 months

Tuesday 11th January 2011
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Hi, im new to the forum and im looking to convert my car to LPG but have a few questions first. Sorry if some of these questions sound a bit dumb, im new to the world of LPG.

I have a 2001 BMW 325i which i have had for a couple of years. I bought it because at the time i did very little mileage but now i have a new job meaning i will be doing much more miles now.

It currently averages 21mpg around town and 34mpg on the motorway. I understand that running on LPG lowers the MPG, so if you take into affect the lower price of LPG, what is the overall MPG i would get on LPG?

I assume this question has been asked many times before, there are many systems around so has anyone got a link/guide to these different LPG systems?

Is it true that the engine will only switch to LPG after the engine has warmed up? If so, getting a conversion may not be that beneficial if i did a 15min journey.

Anything else i need to know?

Thank you

nottyash

4,671 posts

202 months

Tuesday 11th January 2011
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http://www.drivelpg.co.uk/savings_calculator.php

Hi
I was looking at this only 2 weeks ago for my 2001 525. (same engine as yours)
I was quoted £1250 all done and at 20000 miles a year it will pay for itself in just 1 year.
This is at me averaging 29MPG, at £1.30 a litre with LPG at 75p.

You do get less MPG on LPG but its cheaper and the above convertor takes all this into account.
I think its the equivalent of about 23MPG from 29MPG on petrol.

The system I was quoted for started on Petrol and switched itself over, and back again if you run out.

I am unsure on future job/ milage so am not going for it just yet. If you dont do many miles I wouldnt bother and there is always the factor of what if it goes wrong?

RV8

1,570 posts

178 months

Tuesday 11th January 2011
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Modern sequential systems shift to LPG automatically but I have no experience of them. Basically on my v8 I have a three-way switch; Petrol / neither / Gas. I switch to the middle and run it 'till the fuel in the carbs has worked it's way through, then before it pinks switch over to Gas before the revs drop and it dies. No mean feat it heavy traffic.

I use my LPG even if I'm only doing a few miles (cods to running on dead dinosaur juice just to pick up some shopping) I start off in petrol and end the journey on petrol. I switch over to gas after a few yards on starting but in really cold weather I leave switching over until the temp gauge starts to rise - this is because on all systems (as far as I can tell) the system is heated by the vehicles cooling system (via the matrix) and there can be issues with icing although it's rare as the LPG is very cold at atmospheric pressure, exacerbated by cold weather and a cooling system (although effectively because the water gets hot it acts as a heating system) running cold water through it. Lucky for you the system on your modern BMW will only require you to turn the ignition key, the electronics will do the rest because it'll no doubt be an advanced system unlike mine!

Chose a system where the local LPG service companies and installers all either install them or service them, some will be happier to do work on a kit they are familiar with. Just do a search on local LPG companies and ring them up to ask questions to put your mind at rest.
The cost of the kits (and fitting) usually vary depending on how many cylinders your engine has. In terms of MPG I get 18mpg out of the Defender V8 at about 55mph cruising which drops in the city, I get probably similar on Petrol though if I'm honest. If the system is well set up there should be little difference in terms of performance perhaps some reduction in MPG but really you should look at it as MP£. Once you have worked out the cost of fitting an LPG system and work out how many miles you'd have to do to get that money back and start to pay you - say this takes 1 year it's not so bad but say it takes more like 3 years, will you still want the car?

PS. Please tell me your thoughts on the BMW. I was checking the prices of the E46 coupes other day and they are such good value now, to me they look like a proper car in every respect and I always discounted them as I was under the illusion they were much more expensive (being as they were so expensive when new) I know nothing about them really, I know the larger engined ones (like yours?) are straight 6 and that would be the one I'd have given the choice. What would you say about the reliability and running costs (35mpg actually sounds blissful to me)? Is the straight 6 engine timed by gear, chain or belt? Any inherent faults or untruths about them?

325iMSport

Original Poster:

326 posts

174 months

Tuesday 11th January 2011
quotequote all
Thank you both for the replies.

On the calculator there is a good saving to be made. With my details entered, it will take around 18months for the payback which i think is quite reasonable. Plus factor in that my road tax will go down, free congestion charge and the value of my car will go up very slightly seems like all good to me.

In regards to the E46, i have had mine for around 30 months and its been really good. Other than servicing it once, the only other maintanance i have had to do is change both rear shocks and a window regulator. I found parts prices very reasonable too.

Well it does 34mpg when you do around 75ish on the motorway. I did a 200 mile trip recently with the cruise set at 70mph and it did 38mpg, considering the official figure is 40mpg.

Any other views on the LPG idea?

nottyash

4,671 posts

202 months

Tuesday 11th January 2011
quotequote all
My avearge is about 29 mpg but thats everywhere. stop start drops it right down, but I agree I manage 34-36 on motorways.

I never knew it dropped road tax down.eek

325iMSport

Original Poster:

326 posts

174 months

Wednesday 12th January 2011
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Any other views on the LPG idea?

BarnatosGhost

31,608 posts

260 months

Wednesday 12th January 2011
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Get a car that is already converted. Start saving on the first day.

325iMSport

Original Poster:

326 posts

174 months

Wednesday 12th January 2011
quotequote all
That would be idea but i have been having a look on autotrader for the last few weeks and cant seem to find any E46 saloon M-sport LPG frown

BarnatosGhost

31,608 posts

260 months

Wednesday 12th January 2011
quotequote all
325iMSport said:
That would be idea but i have been having a look on autotrader for the last few weeks and cant seem to find any E46 saloon M-sport LPG frown
They'll be few and far between, but definitely the best way to do it. Perhaps only £3-500 more than a standard car.

matt21

4,307 posts

211 months

Wednesday 12th January 2011
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BarnatosGhost said:
325iMSport said:
That would be idea but i have been having a look on autotrader for the last few weeks and cant seem to find any E46 saloon M-sport LPG frown
They'll be few and far between, but definitely the best way to do it. Perhaps only £3-500 more than a standard car.
My car is for sale. a 2000 X 530i SE auto, sat nav, TV, phone, leather, FBMWSH, 178,000 miles and a recent LPG install - BRC 80 litre Stako tank in the boot great system - price? not much more than a decent 6cyl system!

I did 27mpg on petrol, do circa 23mpg on gas which has equated to 45mpg. My tax does not go down as its pre 2001 but I can be congestion charge exempt for a tenner per year.

I converted in April and with the mileage I do should breakeven soon after the year is up.

Overall very pleased, 300 mile range is a bit of a pain and 2 fills per week.

Give me a PM if you need any details, been through the whole process you have so does the research. If not interested in mine please make sure you buy a decent system - warranty is a bonus (I have 15mths left!)