Andy Dingley wrote:

A mile of gentle driving just isn't going to hurt anything terminal.

I dunno - I've seen holes in pistons after only a few minutes
running a diesel on petrol.

That's not gentle driving though. That's some serious detonation going
on, and driving on despite it.

Possibly - all I saw was the end result, and a driver who was
adamant it was only a few minutes before she realised what had
happened.

--
Grunff