Diesel fuel

My diesel runs the same on any brand of diesel. I did think for a while that Jet wasn't as good on economy as Shell / Tesco / Asda but it turned out that in the end it was just the same.

-- James

Just ask yourself where the supermarkets get their diesel from. I'm not suggesting that it is Shell, but they certainly don't own their own refineries and so it comes from the 'multi's' just like the more expensive fuels.

Kev

That's ridiculous - it's bad enough when this kind of crap gets spouted about petrol, but diesel???

Diesel is a relatively unrefined product, made up of a wide range of chain lengths. Most diesel engines will happily run on quite a range of oils.

My experience is that whatever they put in diesel fuel in the winter causes a loss of power and increased fuel consumption. (Unless it's just down to the cold weather). When I leave these shores and top up with continental fuel I notice that it smells like diesel- not like some scented cat pee, provides more power and fuel is consumed more economically. DaveK.

Some diesel engines can run on pretty much any oil you care to name, military multi-fuel engines will run on anything from petrol to heavy fuel oil (tarry stuff) and are designed to. Modern car diesel engines are a bit more picky on what they run on it has to have a minimum Cetane rating, the correct viscosity and lubricity, but they are nowhere near as picky as a petrol engine.

Vegetable oil is probably more precisely formulated than forcourt diesel, although I don't think mother nature had in mind running diesel engines on it when she forumulated it...

I think you've been filling up at the pink pump...

IME, it's not ridiculous.

I live near Stanlow (Oil refinery), which will deliver petrol to all the local places.

My car (and my wife's car) run _much_ better on Shell 95RON than it does on Tesco or Sainsbury's 95RON. BP 95RON almost causes a mis-fire! Sluggish performance etc.

Pete.

It is rediculous.

no it doesnt. the difference in fuel performance is purely down to the placebo affect.

a motoring magazine did a test a few years back by telling people their petrol was from different garages, eg shell was esso, esso was texaco ect ect.

"shell" branded rated the higest even though none of it was actually shell-it was other brands. supermarket barnd was rated lowest even though it was a top brand.

its all down to people thinking the fuel is better. it isnt.supermarket fuel gives *exactly* the same performance.

with regards to diesel did you know that a mercedes engine will run on molten lard (fact)? peugeots will run on neat vegetable oil with no decease in performance. that's how tolerant their diesel eninges are of fuel types. anyone who says different dieles has an affect is having a laugh, sadly.

harry.

So please explain the difference seeing as it all comes from the same refinery.

SpOnIx

I know for a fact that Sainsbury's in the Northwest, use Stanlow and Manchester refineries for deliveries. They use ALL the major brands of fuel delivered in unbranded white tankers.

By the way, they dont own the filling stations, just provide the staff to run them.

Kevin B

I've been driving petrol vehicles for 42 years and diesel vehicles for 28 years and have never ever noticed any differences between fuel brands. I always just filled up with whatever was available at the time, although for personal use, usually the cheapest. Are you suggesting that the supermarkets are deliberately adulterating their fuel? This would be tantamount to marketing suicide.

Terry D.

There is some truth in what you say. Many continental countries are still selling low sulpher diesel (not ultra low as in UK), which has slightly greater energy content and often produces increased performance and better economy. Difference is normally isn't huge, but is still noticeable. In my experience I get around 5% more out of French fuel.

Alec

Additives, detergents & the like.

It's like saying that _all_ alcoholic drinks from one brewery will all be exactly the same, even if they brew 4 different types. The raw material may be the same, but if Shell add detergents & things to their petrol, and Sainsbury's don't, then the petrol isn't the same.

If all petrol is identical, why did the pre-may 1998 Mondeos sticking valve problems become worse when run on supermarket (I.e. cheap) petrol?

All I know is that my car runs quieter and more economically on Shell petrol than Sainsbury's.

Incidentally, from 'Fuel and Emissions' in HJ's Book of Motoring Answers

The AA has developed specifications for petrol additives based on industry standards for detergent performance. An AA spokesman tells me that the AA is happy both with the quality of detergent and the relative quantity of it in Jet petrol, and also with Jet's procedures for ensuring there is adequate quantity of the right detergent in each delivery of petrol. (While others add it at the refining stage, Jet tanker drivers add it either to their tanker loads or on delivery.) The AA wants its standard adopted industry-wide, but this has not yet happened.

Pete.

So it's entirely down to the placebo effect that BP petrol causes the car to not go when you push the throttle down, and to get s***ty economy?

With shell petrol, I can rev the car straight from idle to 6500rpm, and it's smooth.

With BP petrol, the car runs out of puff at between 5500rpm and 6000rpm, and gives an effect very similar to the "Cylinder 1 HT lead misfire" so beloved of this engine. It just won't go round any faster.

Put a tank of Shell in, and it's back to normal.

Sainsbury's isn't as bad as BP.

Pete.

Don't get me started on beer...

Too late. Your first statement isn't far from the truth. I fall prey to the placebo effect too - I will swear blind that I like Stella more than I like other 5% lagers. But do a blind test, and I can't tell the difference. Yet for some bizzare reason I persist in buying Stella.

They put stuff in to stop it freezing...this in effect dilutes the fuel slightly which gives the effect you noticed.

sPoNiX

Errr....didn't SHELL add something to their fuel that destroyed valves a few years ago?

I've started running on Shell diesel on the basis that its 1.4p/l cheaper than anywhere else at the moment. I can't comment on fuel consumption, but I can confirm that it doesn't foam as much when filling up when compared to the stuff at the local Sainsburys or Esso filling stations.

Personally all this talk of supermarket fuel being inferior is a load of b******t put about by fuel companies trying to maintain margins by getting you to fill up at their gaff rather than messrs Sainsburys/Tesco/Safeway et al.

/john

I don't know about putting stuff in, but the composition of winter and summer diesel is different. There is a higher proportion of more volatile elements and a lower proportion of waxier elements in winter fuel. There are also slight differences in petrol too, more to do with maintaining volatility for easier starting than eliminating the possibility of freezing, however.