Page 1 of 3

Wrexham LPG prices

Posted: Wed Aug 29, 2007 6:21 pm
by clanless
Well, ever since I had my car converted I have been buying LPG at 42.9 p per litre. The 'Texaco' garage in Wrexham put up their price to 46p so I voted with my feet (tyres?)and went to another garage. There is only one LPG garage which is local to Wrexham so it looks suspiciously like profiteering to me.

I filled up with 'Shell' LPG, again at 42.9 p per litre and the car RUNS MUCH BETTER. So from my experience there is a marked difference in LPG quality even from the major retailer. I'll being filling up with shell from now on in. 42.9 is the cheapest I have seen LPG.

Re: Wrexham LPG prices

Posted: Wed Aug 29, 2007 11:24 pm
by mak-uk

Do Countrywide Autogas have an installation anywhere near there? ... ntentbasic

In relation to the quality of LPG:
There are 4 major differences in LPG that can effect the performance and mileage:

1 Type of gas(es)
2 Amount of heavy ends
3 Solvent
4 Combustion differences

1 Type of gas(es)

The LPG is available in different mixtures, from pure propane upto a mixture of 70% butane and 30% propane.
The 70% butane and 30% propane mixture gives the highest performance and mileage. This mixture gives less tank pressure than pure propane and therefore can't be used in winter. The oil companies adapt the mixture to the time of year.
In some countries the LPG is all over the year pure propane.
The propane will give less mileage than the butane.

2 Amount of heavy ends.

When you fill the tank of your car you will not only get the liquefied propane / butane but also some heavy ends.
The heavy ends are oil based fluids. These heavy ends are normally harmless and will grease your vaporiser.
Only when the amount of heavy ends comes above a certain level they build up in the vaporiser.
The result will be that the membranes can't operate proper and the engine might run lean.
The problem can be solved by draining out the heavy ends or cleaning the vaperiser internal.

3 Solvent

Sometimes there are (accidentally) aggressive solvents in batches of LPG.
These solvents are capable of destroying the membranes and valves in the vaporiser.
Some of the solvents are so aggressive they will decompose the membranes in a few weeks.
If you had a fill with aggressive solvents contact your LPG supplier and show him the membranes.
Your LPG supplier must contact the oil company and inform him about the problem.
The oil companies usually pay the costs of the membranes and the labour.

4 Combustion differences

LPG must combust like petrol. The percentage of oxygen regarding to the amount of Co in the exhaust gases has to be the same as on petrol.
If this is not the case a lambda controlled LPG system might run very rich or very lean.
A rich mixture will result in a higher fuel consumption.
A lean mixture will result in a drop in power and a very high fuel consumption and might even damage your engine.

Testing of the LPG quality can be done in a simple way:

1- calculate the mileage you get from different batches (suppliers) of LPG.
2- install a vacuum gauge and look for the vacuum at a certain constant speed on a certain road.

It is also possible with an EFI engine by switching between LPG and petrol and comparing the needle position of the vacuum gauge.
If the vacuum rises the LPG is probably of a higher quality, if the vacuum drops the LPG is probably of a lower quality.

If the needle position is the same, the engine will not run too lean, the engine might run rich. You can test it with a Co-tester pre-cat. If the Co is over 1%, the quality of the LPG is probably higher. By re-adjusting the main flow adjuster you can profit by the higher quality of the LPG.

Re: Wrexham LPG prices

Posted: Thu Aug 30, 2007 3:47 pm
by clanless
Thanks for the info - an interesting read.

Unfortunately there are no 'Countrywide' places within driving distance - which is a shame as I understand that they are very reasonably priced.

Whether shell or texaco or whatever, I tend to get around 33 - 35 mpg which is acceptable.

The difference was in the cars drivability - by this I mean it was more responsive and less jerky when accelerating hard. My car has an older type single injection petrol engine, so it has a single point LPG conversion with the mechanical stepper motor. The stepper motor cannot respond quickly enough on hard acceleration so I get a slight jerk as the stepper motor opens up. Not a problem as most of the time I drive sedately so don't notice anything. I'm not sure if the injection systems are any better as they may also rely upon a mechanical stepper motor.

Just to be clear - the installation itself is very professional - the single point system was cheaper than multipoint - and was the system most suited to my engine - so I do not in anyway regret the conversion. I actually much prefer driving on LPG.

It is the Romano system, and I must say looks much better quality than the one shown in the pictures on your website - I have also heard that the older single point systems are more reliable than multipoint (this makes sense as they have been around far longer and any problem will by now have been ironed out.)

Re: Wrexham LPG prices

Posted: Thu Aug 30, 2007 9:50 pm
by mak-uk
Well, first system I had installed was that it was a Romano N - third generation, multi-point sequential - not that you could tell it is 'quality' from the components. It was a combination of the system and the way it was installed (badly) which is why it did not work right.

With LPG systems, so much depends on the quality of the installation - as I have discovered! :shock:

Re: Wrexham LPG prices

Posted: Fri Aug 31, 2007 8:14 pm
by clanless
For fear of going off topic - you have hit the nail on the head - the only way to select any tradesmen, garages, double glasing companies etc. is to ask for a personal recommendation from someone they have done work for and who you know and trust. I'm not just saying this -my bungalow extension is being undertaken by a builder who was recommended by a friend. I didn't even bother looking at anyone else.

Flashy web sites, glossy brochures - mean nothing.

Re: Wrexham LPG prices

Posted: Wed Sep 05, 2007 7:04 pm
by clanless
Well, there's a surprise, the cost of the Wrexham LPG has gone down to 45p. Perhaps too many people were going elsewhere? They need to cut off another 4p before I go back there again.

Re: Wrexham LPG prices

Posted: Fri Sep 14, 2007 8:14 pm
by entwisi
I use two different places, A Farm shop just off J19 M6 (Holly Tree Fram) and teh local Shell. Both are identically priced. TBH I've never noticed a difference in performance across either site and mileage has been consistant from a tank full give/take my heavy right foot from it.

Re: Wrexham LPG prices

Posted: Sat Sep 29, 2007 8:18 pm
by Knightkiller
Hi Clanless, have you ever looked at Smithy Garage on Acton Road? They're my local refuel station in sunny Wrexham, and even if the service isnt always the best, theyre LPG price is usually good. Also on the Gresford Road, going past MFM, place with the van hire, theyre usually cheap too. :D

Re: Wrexham LPG prices

Posted: Sat Sep 29, 2007 8:22 pm
by Knightkiller
Oh, by the way clanless, they're is a countrywide place close by. Not advertised but its on the Wrexham Industrial Estate, just past the recycling centre (opposite side to Kelloggs).

Sorry for the double post.... late brainwave.... as always :roll: :lol:

Re: Wrexham LPG prices

Posted: Sun Oct 21, 2007 1:19 pm
by clanless
Thanks for the info.

The station past MFM was the one I was talking about - they have bunged on the 2p per litre increase as well.

ASDA in Queensferry are still selling at 42.9 per litre - the other garages that I goto have increased by 2p.

The Countrywide place on the industrial estate - do they have an lpg filling pump? What are the prices like? Sounds like it might be worth a visit.