Chris Hogg wrote:

I always thought the smell of the exhaust of high-performance engines
such as in sports and racing cars at hill climb meetings etc was due
to the use of 'Castrol' somewhere in the fuel mix (whatever Castrol
was), but I'm probably wrong.

"Castrol R", it was the classic engine oil used in early racing
engines, do a web search and you can read all about it.

--
Chris Green
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