Best Petrol for economy

[bcr5784]

I've never been one to find anything "reassuringly" expensive, so I tend to use the cheapest petrol I can get. In my case it tends to be Tesco Momentum. I was somewhat reassured that it's octane rating was higher than many of its competitors. That said, over the years, many people have said that supermarket petrol is inferior. Most have been people who are of the "reassuringly expensive" pursuasion - whom I generally ignore. However one or two are of a more analytical mindset and have actually done back to back tests - so I did so myself - using Shell Vpower rather than Momentum in my 981 Cayman S (PDK)

It's always difficult for Joe Public to do genuinely objective economy comparisons - traffic, wind, temperature all make it difficult. Over a few weeks of mixed motoring I'd come to conclusion that VPower definitely did give better economy - but wasn't sure how much. Last weekend I was able to come to more definitive conclusions. I often make a 200 odd mile trip to the West Country, predominantly motorway but with a mix of dual and single carriageway too. Traffic generally limits speed to vaguely legal so it's mostly with PDK in Normal, but odd bits of manual and a fair number of overrides. I normally expect to get around 37 - 37.5 mpg in decent conditions, never more. This weekend, with only light wind I got 39.7 and would have got over 40 had it not been for a mile of stop start traffic.

So I'm pretty convince that VPower has a couple of mpg advantage over Momentum on a long run, and, if you can get it for even near the same price, is a much better buy. Can't say I noticed any performance or smoothness advantage though.

I also tried a similar test with my wife's car - a Seat Ibiza 1.4 Ecotsi. Even though it's a turbo with a 10:1 compression ratio it only requires 95 octane fuel. On that car VPower did give an economy boost over 95 octane Tesco Petrol (as does Momentum), but we couldn't detect any advantage with ordinary "FuelSave" Shell. However the short journeys it makes make definitive conclusions more difficult. In any case VPower or Momentum wouldn't be cost effective, given the price differential to regular petrol.

Anyone come to similar/different conclusions?

Edited by bcr5784 on Tuesday 15th August 09:30

[bcr5784]

Koln-RS said:

I do think Shell have done a very good marketing job with their V-power, in the same way that Mobil did with Mobil 1, but I honestly don't believe there is a detectable difference between fuels in most modern cars for road use.

It would be nice to think that the extra cost brought some benefits, and there may be a placebo effect, but I'd be interested to see scientific evidence that it confirms a measurable difference in normal use.

I think the test I did does confirm measurable evidence at least on long runs. Haven't done back to back with Shell vs Esso vs BP, but I'm 100% sure VPower gives better economy than Momentum.

[bcr5784]

engineermk said:

. All the tests in Europe are run to CEC procedures and several independent labs run the tests; check out Millbrook, ISP, etc. Its all closely regulated and if the oil company claims its will give you 1mpg more, they can prove it.

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It's what the 1mpg more is relative to that is significant. I'm not interested in the fact that shell diesel gives "up to" 3mpg more relative to their own fuel without any additives, it's how it compares with the opposition that is important - and I haven't seen anything which gives that sort of information, hence the limited tests I made, albeit under conditions that aren't anything like as controlled as I would wish.