Quote:
Originally Posted by t vago
Furthermore, you neglected to mention that TCD schemes generally work transparently - if a driver needs more power than the engine can provide with half its cylinders shut off, the engine computer will automatically and seamlessly activate the remaining cylinders.
Multiple stages...
Sounds needlessly complicated to me. The auto manufacturers seem to have licked this problem with modern computer controls.
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The fact is driver always needs more power than the engine can provide with half its cylinders shut off, so TCD could be ALWAYS OFF. ONLY ON AND OFF!
LOOKS VERY CHILDISH. This is only 2-way entery level control.
TCD diactivates a fixed 50% of the cylinders, which is a number trend to over-deactivation under most of common driving conditions. As a result, TCD could only be activated within a very narrow range to avoid over-deactivation under fixed 50% deactivation. Therefore, its utilization could become very low, as one of its user commented at end of [#] that “The 4-cylinder option (Active Fuel Management) only works when coasting or driving down slope. (It) does not engage or remain ON for level road.” In contrast, DCD could make deactivation ratio variable and well optimized between 0% and 50% to match various driving conditions, being activated most of the time and 100% of the time during city driving mode, yielding very high utilization. Higher utilization means more chance for fuel savings.
Multiple stages... means advanced control and better performance, resulting
higher fuel savings. Why needlessly complicated? Ridiculous!!! You prefer
entery level technology than advanced technology? Then you may wish to
go back to play with steam engine that thermodynamics well applies but
don't need control electronics!
[#] Bill Siuru, Variable Displacement for Better MPG, greencar.com, 10/01/2007
http://www.greencar.com/articles/var...better-mpg.php