>In previous threads on this topic the chemically inclined answered that PTFE
>breaks down at high temperatures to form highly corrosive acids which then
>damage the metal it is supposed to protect.  So, while there is a noticeable
>benefit at first, there is a terrible end result.  The breakdown temp is
>somewhere around 400 degrees Fahrenheit I think.  While the oil is not at that
>temperature all the time the cylinder walls are often hotter and the PTFE is
>being applied to them and washed off again with every stroke of the piston.
>The corrosive by-products build up in the oil and damage everything it touches.

Aha! So we'd better put teflon-containing additives in the same file as
Motor Up...the round file...

Andrew Grebneff
Dunedin, New Zealand
VW & mollusc nut
1969 Kombi with Corvair 2.4 & Powerglide
1975 Kombi derelict ex 3.6 Toyota V8
1984 Caravelle 3.8 Holden V6
1984 Mitsubishi Galant Sigma 2.0 (FWD)
1986 CE80 Toyota Corolla 1.8DX diesel
1989 CT170 Toyota Corona Select 2.0 diesel