Tman wrote
One 80-year old stick here has a nice 172. No hangar. When planning
the next start to be in cold wx: Shuts the thing down, drains a full
GATTS jar of avgas and pours it in the crankcase. Starts it back up
for
1-2 mins.

I share a 1959 C-172 with a friend, and although we have no need for
it here in Florida, the following is from the Cessna Owner's Handbook:

Oil Dilution System
(Optional Equipment)
To permit easier starting in ex-
tremely low tempertures. an optional
oil dilution system is available. Used
immediately before the engine is shut-
down. this system injects fuel into the
engine oil and reduces its viscosity.
When the engine is agin operated,
the fuel evaporates and is discharged
through the breather so the oil re-
sumes its normal viscosity.
The oil dilution system consistS of
a solenoid valve on the engine fire·
wall. connected to the fuel strainer
outlet, and to a tapped plug in the
end of the low pressure oil screen on
the engine. The valve is opened by
pressing a push-button switch on the
instrument panel.
Detailed operating procedures for
the oil dilution system are contained
in section III.

When I flew P-2V Neptunes in Maine during the early '60s, oil
dilution was a common precedure during winter months on those
large R-3360 radial engines.

Bob Moore