>The point is automatics generate more heat and heat is destructive, plus
>adding an additional cooler offsets the reliability increase (to some
>degree) by adding additonal components to fail. Automatics are more
>complex and more sensitive to contaminants than Stds, Run an automatic
>hard when it's 2 quarts low for any length of time and you'll be
>visiting Aamco soon. Granted it won't do a std any good either but it
>will survive much longer.
Actually, automatics are far simpler, if you count only the torque-
bearing parts. The hydraulic controller (that rats maze) is the
complicated part. And I expect in 10-20 years a computer and servo-
controlled valves will replace that.
An automatic is a series of planetary gears, with a hydraulic coupler
(the torque converter) driving it so the shifts are smoother. A manual
transmission has multiple gears sliding on shafts, with the friction
of the synchronizers controlling how smooth the shift is.
As to contaminant sensitivity -- it seems to me the most sensitive parts
are the wet clutches in an automatic (which also smooth shifts). There
aren't too many wet clutch manual trannies anymore -- I suspect because
they're not as reliable and efficient as dry clutches. Maybe someday
we'll see dry-clutch automatics too.
All-in-all, I don't think autos would account for 70% of cars sold if
they weren't pretty darn reliable.
Jim
The PC 2nd Amendment: A well regulated population being necessary for
the security of a police state, the government's right to ban and
confiscate arms shall not be infringed.
-- attributed to Vin Suprynowicz, 1995
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