LPG - Less Point Guys

Combustion is a funny old thing. I was talking to a mate of mine this week who has just changed his V8 3.9 litre Land Rover Discovery for the diesel variety. His old V8 had an after market LPG conversion but it was still too expensive.

Matt explained that the octane rating of LPG is 112 but the flame front is so slow he had to advance the ignition by 12-15% to get the bang in the right place. Any later and by the time the piston was going down the bore the exploding air/fuel mixture was stumbling down the bore after it when the fireball should have been forcing the piston down there.

Despite advancing the ignition, his Disco was noticeably more sluggish and returned no more than 15 mpg. It seems that LPG doesn't burn very well. Maybe a more sophisticated engine management system would improve performance and economy but it's unlikely anyone will engineer bespoke systems for what are often quite old engine designs.

Since LPG can cost up to 63p/litre and his new diesel Disco does at least 25 miles to the gallon (if we still have gallons) there wasn't much saving. And that's before taking the cost of conversion into account.

Coincidentally, another mate of mine, John, told me of his neighbours who have a Subaru Imprezza. They love this car. When they first got it they explored its full performance potential - and got 4 mpg. They have now shelled out on an LPG conversion, which makes the car much slower. That's a judgement call, though. A slow Imprezza is still fast.

The conversion has also de-valued the car for re-sale.

(Matt tells me that Discoveries like his are so cheap nowadays they are unlikely to depreciate any further.)

John and I reckon his neighbours should have kept their Scooby stock and spent the cost of conversion on a Nissan Micra or something.

Dipping diesel tanks

Back from my travels to Edinburgh, I was shooting the breeze with my neighbours. Around here tractors are a great source of pleasure. I'm not into them but a lot of my mates are. One or two could be Vintage Things.

Most of my tractor fan mates are called Andrew. You'd think this would make life more convenient but it doesn't. More on that another time.

Anyway, I'd just bumped into Andrew in town buying some "proper job" aluminium number plates for one of his Fordson Majors. He said how much he was looking forward to the forthcoming vintage shows despite the price of fuel. He was determined not to let anyone "piss on my firework."

When I came home, Andrew and Andrew were fitting a warning beacon to Andrew's souped up, hot rodded six-cylinder Major. Andrew's got one of these, too. In fact he's got three now and is well into double figures with his tractors.

I told them I'd just seen Andrew and they knew all about what he was up to because Andrew had told them. (That would have been the fourth Andrew - I hope you're following this.)

They then went on to tell me that they are expecting "the Ministry" to be lying in wait outside the vintage show grounds this summer dipping the tanks to see whether they are running their tractors on white diesel or agricultural red diesel.

As their tractors are now preserved and no longer used in agriculture, it is apparently illegal for them to use the much cheaper red stuff. "The Ministry" will be dipping tanks to make sure they are using DERV fuel - Diesel Engine Road Vehicle fuel.

The recent fuel price increases are hitting everyone but it seems a shame to target the preservation movement.

I don't see how dipping the tanks would prove anything. After a life time of agricultural use the fuel is probably a delicate rose. The red dye goes a long way. Just a little in your car or van fuel system would be grounds for a persecution, sorry prosecution, should you be caught.

There are rumours that domestic heating oil is being substituted for white diesel and that you can declare a certain amount to "the ministry" to avoid prosecution. Nobody knows anyone who has tried this, though. The word on the streets - well lanes, seeing as we're in Cornwall - is that common rail diesels are damaged by heating oil so somebody must have tried that.

There are also rumours that if you strain red diesel through slices of white bread the red dye comes out. I don't know how many loaves per gallon you need but this has the ring of truth about it.

Interest in bio-diesel is growing rapidly. I first read about this in the Citroen Car Club magazine about eight years ago. That was when folk began to notice that, having been seduced by diesel's lower fuel price and running costs, the price of their DERV fuel was creeping up beyond unleaded.

So we have the government generating lots of lovely revenue to invade foreign countries, stage Olympics and build domes by taxing fuel, "the ministry" chasing the general populace about because only an idiot would willingly pay the high fuel prices and the general populace searching for cheaper fuel alternatives.

Like LPG. Mind you, I think that's a bubble that's about to burst. Once the infrastructure is in place and enough people are using it, the government will raise the tax on that and invade Iran to make the world a safer place. And protect our oil supplies.

Meanwhile, the Andrews (none of whom would ever answer to Andy) will be turning the clock back even more this summer and showing their oldest vehicles, which typically run on paraffin. And there's nothing (at the moment) that those fun police at "the ministry" can do about it.

It seem that fireworks will indeed be kept dry. In some cases they'll be ceremonially sprayed with red diesel.