Classic cars forum & vehicle restoration.

[pigtin]

I came across this on an American website:

'Today’s fuel manufacturers generally start every grade of fuel they produce at or below 87 octane. They then “boost” the octane rating by adding alcohol to the fuel in the form of ethanol to achieve the desired octane level. The higher alcohol levels in fuel can certainly cause some running issues that are very undesirable. Symptoms that may arise are engines that are hard to start when hot or cold, engine dieseling (also called run-on), vapor lock, or just poor overall performance. By using 87 octane fuel, you will be assured that you are using a fuel with the lowest possible alcohol content, thereby lessening the chances of the above mentioned problems. We also recommend the use of a good fuel stabilizer such as Sea Foam engine treatment. Regular use of this product will keep the fuel system clean as well as keeping the fuel from deteriorating and causing your fuel system problems and the poor performance issues mentioned above. Alcohol blended fuels begin to break down within three weeks of the refinery process. Likewise, alcohol blended fuels also attract moisture that will eventually decrease the octane of the fuel, and cause your engine to perform poorly. So if you have the same fuel sitting in your tank for a period of three weeks or longer, the fuel is starting to separate and will likely be causing you some problems very soon thereafter'.

This does apply to two-stroke mix and I know very little about the petrol I buy and whether it has alcohol in it, but the deterioration rate rang alarm bells withe me as it may do with anyone who has cars that stand unused for any amount of time.
Are UK fuels boosted with alcohol? I don't seem to be able to find out.

[Uncle Joe]

I cant really say what applies to modern fuel, but didnt Cleveland that used to be on sale in the UK in the 50's/60's have alcohol in it to boost the octane rating? I dont remeber any problems back then.

Dont forget that in the US, its 87 ROZ octane, roughly the equivalent of the 95RON octane that is sold in the UK.

UJ