Switch Pitch

[Gary Derian]

Reducing pumping losses at cruise is a key element in improving fuel
economy.  Some tricks like V-8,6,4 were complicated and had many control
problems.  Taller gearing achieved some improvements but dropping cruise rpm
into the slip range of torque converters negated much of the improvements.
At first, reducing converter stall speed was used but performance really
suffered.  The next development was a TCC which permitted a higher stall
speed when needed but little or no slip during cruise.  Once TCCs were
available, overdrive automatics could be used to improve economy even more.

Gary Derian <gderian at cybergate.net>

>sounds like the new tc's have much more slippage, is that a correct
>assumption?? and the lockup tc is an attemp to restore what was lost
>( I was a mechanic at a bmw,saab,subaru dealer in the 80's and live in
>car hell -> salted roads so I never got my hands on one of these)
>
>Pat Ford                           email: pford at qnx.com
>QNX Software Systems, Ltd.           WWW: http://www.qnx.com
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