Dave Stadt wrote:
:The
: cylinders themselves have choke (they're slightly smaller bore at the
: top), with the
: thought being they'll expand to be straight when they heat up during
: normal operation.
: Those two things are the primary reasons.... lack of oil and scuffing of
: cylinders.

: Doesn't play. The pistons are aluminium and the bores are steel. In cold
: weather the aluminium pistons shrink more than the steel cylinders and
: clearance actually increases. The rings are steel and follow the cylinders.

True... except the piston is warmed by the first few seconds/minutes of
combustion much quicker than the steel cylinders. It's not the starting so much as
the dissimilar warmup. If the cylinders are pre-warmed, the temperature differential
to be transitioned through is lower. Granted it's engine preheater propaganda,
I believe there's some truth to the research in http://www.tanair.com/article6.html.

If you get high-time from your engine without preheat, then good for you.
Nobody said that cold-starts are the only cause of engine wear, and I'm sure that for
particular engines it's worse than others. As always, YMMV.

-Cory

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