Today's silly question - but I thought I'd ask

I think I probably know the answer to this, but I thought I'd check with you more knowledgeable folk.

The man clearing out (and demolishing) our old shed has unearthed a 20ltr metal jerry can which I recall Mr. F'smum buying and filling with diesel some years ago (by 'some years', I mean probably 8 at least). It's never been opened since it was filled and the can itself is in perfect condition.

As we no longer have a diesel vehicle I was thinking of offering it to my neighbour but, before I do so, I'm wondering .... will the fuel actually be any good? The last thing I want to do is mess up his engine big time.

 

Debatable. I would say it may contain water from condensation. Others have said it can contain a fungus, the engine wont mind the fungus, the injectors will (They block) some have said they have used 15 year old diesel no problems.
Best thing, ask your neighbour would he like it. But do tell the age, his choice then.

 

Tell him wot you have told us!!!! LET Him make up his own mind im sure he would be over the moon with the jerry can they fetch good money :WINK1:

 

I don't know about diesel, but if it had been petrol, I'd have said most definitely no good for use in a car now.

When petrol has been left to stand for too long it starts to separate into a waxy jelly (basically vaseline). Run and engine off it and first the valves would over heat because the runny bit is lower octane (the higher the octane rating, the more controlled the burn inside the engine), then the whole thing would conk out anyway because it would be a race between the fuel pump failing, the fuel filter clogging, the injectors clogging, or the lambda sensor in the exhaust being fouled.

Diesel might be different. I know it is far less refined than petrol (which incidentally is why diesel used to be much cheaper than petrol before diesel cars gained popularity). So maybe diesel engines are less fussy. I know you can run a diesel off vegetable oil for example, but not long term.

 

To continue the silly question process:-
Clueless - how come that Diesel is less refined, therefore cheaper to produce and was much cheaper than petrol, is actually MORE expensive these days.
I can't be because there's more Diesel cars - there are still far more Petrol models.
My guess is the Manufacturers spotted a profit potential and the Govt. rubbed their hands at the thought of all that extra tax, therefore there is no incentive to ask a Regulator to investigate profiteering.

 

Diesel is a by-product of the refining process that produces petrol. Its probably a bit more complicated than this but this is my simplistic understanding. You take crude oil, and you evaporate it and condense the vapour. The captured liquid is fuel grade oil, something like parafin if I understand correctly. You then evaporate that and condense the vapour, and you get a small quantity of stuff that goes on to be petrol. The 'waste' is a much larger quantity of stuff that goes on to be made into diesel.

For ever, diesel was cheaper because it is cheaper to produce. Diesel engines were rubbish, useful only for insanely large engines that needed lots of torque but where smooth running, clean burning, and higher horse power at a wider range of revs were attributes that didn't matter. I.e. lorries, diggers, boats, or anything else where the engine was to deliver a high torque within a very narrow rev range. Diesel was therefore cheap as demand was limited to those that would buy in bulk.

Car manufacturers starting rolling out diesel powered options, mainly for the caravan pullers, who's choice of car was about torque at lower speed rather than comfort and performance.

People quickly realised that diesel cars worth having if you did a lot of motorway miles (sales reps, couriers etc) where you didn't need much power to sit at 2500 rpm rumbling along mile after mile of monotonous motorway, so demand grew.

Eco laws came into effect, meaning car manufacturers were compelled to make their cars use less fuel, but they still had to compete. It didn't take them long to realise that the only reason diesel engines were so dirty was because half the fuel was spat out unburned, and that with simple tricks like exhaust gas recirculation and more precisely measured fuel injection they could achieve a much cleaner, more efficient burn. Incidentally, the same is less true of petrol, the unburned byproducts of petrol do get sent back round nowadays, but you can't get the same high efficiency of burn with petrol because the excess heat produces nitrous oxide which can make the exhaust pipe pop off and is very bad for the environment apparently.

Soon the car manufacturers further realised that with lots of clever electronics, plus a turbo, you make a diesel perform as well as a petrol engine, but with much lower emissions and of course a superficially reduced running cost (I say superficially reduced because in real terms, a diesel engine is more expensive to maintain than its petrol counterpart).

That brings us to nowadays. Yes there are still more petrol cars than diesel cars, but diesels are less 'marginalised' than they used to be. For example, VW's 'hot hatch' has always been the Golf. Forever it was the Golf GTI (their flagship petrol model). Now its the TDI (diesel powered).

I believe fuel companies apply the laws of supply and demand as much as anyone else does. Work out the pence per mile to fuel a given car, and make sure that that's what it costs. Diesels do slightly more miles per gallon than their petrol counterparts, so you charge slightly more per litre for their fuel. Not enough more to make them equal in running costs (that would be daft, why kill off the market of people buying your waste by-product), but enough to make it slightly worthwhile for people to buy cars that run off a previously difficult to sell waste product.

 

Diesel is no longer less refined due to the emmisions law and less Sulfur
The tax is identical to petrol £2.63 per gallon plus 20% of total cost VAT
52p per gallong for red agricultural diesel same stuff dyde
As there is less diesel sold, it is more expensive, as less crackers used and the emmisions now have to be lower than ever before the producers say it costs them Sooooo much they have to pass it on Believe that if you wish

Jack McHammocklashing

 

All I know about diesel engines is that when, almost daily, I had to drive a 120-odd mile round trip enjoying the scenic delights of the M25 (accidents, roadworks, Clackett Lane, spillages, loose horses and non-specific queues permitting), given a full tank, my beloved Golf Match 1.9 TDi would give me over 700 miles.

That was until some idiot Polish driver, in a Renault Magnum (the blurb for which says ".. an HGV famed for it's all round visibility ...") said he didn't see me , ran slap into the back of me and wrote my Golf off. Fortunately, it was built like a tank and absorbed the impact but by the time the insurance companies had extracted their collective digits, I no longer needed to do that journey and thus couldn't really justify a like-for-like replacement.

Which still leaves me with an 8-ish year old jerry can of diesel and no idea whether it's any good or not.

 

Don't flog it. VATman will want his pound of flesh.