Watered petrol

[peterc]

Roger,
I thought one of your other postings had suggested that 98 Super was better than the standard 95 because of less ethanol. I was trying to indicate that the Shell web site suggests that they have the same ethanol content. E.g. Both 5%
Has this changed over the last 10 years as I was advised at the time my engine was built that it would be perfectly OK on standard unleaded.
Peter C

[Paul Blore]

I think there are two factors to consider Peter. The first one is the octane level, which is dictated primarily by compression ratio, but other factors like the head design, material etc. have an influence. The second one is ethanol content, which seems at best to be variable up to the current 5% maximum.
One of the issues being cited against fuel with ethanol is the separation of any water, but I can't see why a modern vehicle wouldn't be equally affected by this.
Trying to locate fuel with low or zero ethanol would appear to be something of a lottery, even with the major premium brands.

Paul

[Roger King]

One of the issues being cited against fuel with ethanol is the separation of any water, but I can't see why a modern vehicle wouldn't be equally affected by this.

Have a look on the FBHVC website for the list of compatible materials - that's the difference.

Yes, I agree, it's a total lottery. But the odds for low ethanol are higher for the higher octane-rated fuels.