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Old 11-10-2013, 10:57 PM   #8 (permalink)
Master EcoModder
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spyder2 - '00 Toyota MR2 Spyder
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One has to also remember that from the factory, to get good emissions scores transmissions are designed to downshift rather than increase load. Higher load increases NOx, which is the hardest to eliminate with the catalyst. Manual transmissions don't have automatic downshifting, so the top gear needs to be less efficient to not only allow more passing power, but also to reduce emissions on the EPA cycle.
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