I read recently, on a trade advice manual [online] that it was deemed inadvisable to go squirting WD-40 around any components in contact with petrol [with ethanol mixed in]?

On the assumption the WD-40 mentioned would be the original stuff, how accurate is the above assertion. please?

I am not sure why you would want to add WD40 to petrol, E10 or not. I researched the issue you menition and found nothing to suggest this would cause a problem. I have even run some tests:

1. Alcohol and WD40 do not appear mix. This is not suprising a WD40 repels water so any in the alcohol appears as "globules" on the surface.
2. Petrol containing ethanol and WD40 do mix. Again not suprising as WD40 is an oil based product.

In both cases there appeared to be no "ill effects".

Perhaps the following articles on WD40 are of interest:

• WD-40 Myths & Fun Facts Facts
• WD40 suprising uses and places where it should not be used