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Old 03-30-2012, 07:45 PM   #10 (permalink)
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spyder2 - '00 Toyota MR2 Spyder
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Ah I see you're talking about a turbo diesel. I'm not too clear on how different a diesel's powerband looks, but if you shift down, it doesn't hurt economy as long as you're operating the engine near peak efficiency right? Shifting down reduces the load requirement anyways.

I guess the turbocharger + diesel combination changes the rules a little since diesels pass a larger volume of air through at low load than gas engines, and would build up boost fairly quickly. I suppose I didn't think of the fact that higher rpm on a diesel means a lot more gas going through the turbine.
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