BP Ultimate

Is that a typo? 42 to 53mpg is a significant improvement, equivalent to about 17p a litre.

cheers, clive

42.33mpg @ 75p/litre = 12.42 miles per £ 53.75mpg @ 79p/litre = 14.97 miles per £

Stick with Ultimate.

Nope - no typo. As it is, I'm going to keep going with ultimate for another month and see if it continues or if it's just a fluke. AIUI Diesels are usually not too fussy about their fuel, so I was a bit surprised at the result. Call me Mr. Cynical, but I'm waiting for the 'fooled you' light to come on the dash and the mpg to drop...

Tom.

Have you tried going onto the Shell diesel stuff as the Ultimate might have just cleaned your system out a good bit, as ive found has to be done about once a year or two in teh Xantia(same engine as yours) to keep it fighting fit as you could say :)

I've been having similar but not quite so dramatic results on a BMW 330d estate.

Normal diesel on a run = 43mpg. Ultimate seems to be coming in at 48mpg.

Tim

I think diesels can be fussy about fuel. Its been mentioned a few times on various motoring groups about how much better mileage people get on diesel when they fill up in France. Apparently it's to do with us having low sulphur diesel while the continent doesn't.

I might have a go with the BP stuff too, I'm justing finishing a tank of normal stuff with a litre of ATF in it to clean things out first though. Not too sure how much improvement I could hope for though as the last tank did 25.8 to the gallon, which is about right for the engine.

Haven't tried it yet - I'm going to run with the BP for a couple more months and just see what happens before experimenting with other stuff. Interestingly enough, my last car - Citroen BX with the 1905cc petrol engine (scarily similar) used to turn its nose up at BP petrol. The mpg was horrible and it didn't run smoothly, but was happiest with Total petrol. Strange considering it should be all the same stuff and probably from the same refinery, just with differing amounts of fairy liquid[1] in.

[1] Remember the Shell ads - "Cleans your engine with detergent"? That's probably what was in it.

Tom.

And the detergent is cheeper than diesel???

i found the shell new stuff to be no different to normal diesel

No, the detergents and other additives are rather expensive. With car engine oils, the additives in your average gallon of oil costs more than the oils...

-- James