What's the difference between derv and gasoil (red diesel) ?

It all depends on the exact spec of the gas oil. In the uk you can get low quality gas oil that is perfectly ok for use in an oil burner for a central heating system, this has a low cetane rating but may not have the right lubricating properties for a diesel injection engine, you should not use it in any engine you care about. At the same time you can buy ultra low sulphur gas oil that is perfectly ok in all engines and will also run your central heating ok. So ask your supplier is the answer.

So, you are both right, you just need to define the parameters and you will agree.

As he says, central heating oil's got no requirements for lubricity & way larger tolerances for water contamination than road fuel. Red Diesel however should be road fuel with dye in it.

The garage chap is talking out of his arse!

As you correctly point out many Diesel engines fitted to agricultural vehicles like tractors and combines are also the very same as those fitted to lorries.

If anything red Diesel is kinder to the fuel system because it is not ultra low sulphur. Ultra low sulphur Diesel has much less lubricity and causes more pump wear.

Red Diesel also has a chemical marker. You can remove the dye with Fuller's earth/sulphuric acid etc (ask the IRA how to do this!) but the chemical marker remains.

Forget the other reply regarding central heating oil - that's a different thing - 28 second kerosene (for domestic apparatus) and shouldn't be used in modern vehicles. Old engines like the XUD will run on it if you add a splash of lub oil however!

Julian.

your talking out of your arse , as mcheerful as already said there are different grades of gas oil , some suitable for engine use other not they have different cetane values and additives .

The old Pug XUD lumps will run on almost anything, though, including veg. oil straight off the supermarket shelf.

So long as it goes bang when you compress it, an XUD will run happily on it.

The Turbo diesel ones, however, need a certain fuel pump...

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Nick" saying something like:

The garage owner is talking c*ck. The undyed diesel has dye added to it

- up until then it's normal pump full-duty road fuel.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "steve robinson" saying something like:

Red (or green) diesel is perfectly usable in modern Common Rail engines. Do you seriously think Lamborghini, John Deere, Caterpillar and other high-cost agri machinery makers would produce vehicles that would peg out if they were run on dyed diesel? Many of the agri-diesel lumps use CR tech too, you know - or you don't know. Hint - it's the same fuel. In fact, many farmers use a common fuel tank for heating and farm vehicles - dyed diesel.

They don't fill it with heating oil though.

Actually I'm going to have to eat humble pie, since the advent of ULSD the road fuel & red diesel standards have diverged, apparently red diesel doesn't have to meet the lubricity standard.

Gas oil has different grades / additives depending wether its being used as heating fuel or to run engines , whilst you could run your car or lorry on low grade gas oil its not going to do you any favours

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Duncan Wood" saying something like:

Only an idiot would. Actually, Caterpillar issue a tech bulletin about using kerosene if necessary and what to add to it.

You don't have to eat that HP! That's only because the red diesel is automatically well above the minimum lubricity requirements. ULSD had the problem, and a lubricity standard was retrospectively introduced. Some engines suffered pump damage when the ''first generation'' ULSD hit the high street.

Julian.

A twit with half an understanding. Overheard Fred and Joe down the Cat and Fiddle one night?

Red or White, (DERV) it matters not one jot. I'm intrigued by your understanding of Cetane, can you explain, with particular reference to the OP's query regarding the red dyed Diesel and the white DERV.

Julian.

Snag is there's no requirement for it to do so, so unless you know who made it you've no idea whether it does or not.

Road derv has a cetane rating of at least 51, red diesel has a cetane rating of around 45