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Old 11-28-2012, 01:40 PM   #9 (permalink)
Joeggernaut
EcoModding Lurker
 
Join Date: Nov 2012
Location: NC
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Quote:
Originally Posted by Old Tele man View Post
Let me add that todays' modern engines try to maintain 14.7:1 mass air/fuel ratio, not for economy or power, but rather for EMISSIONS COMPLIANCE.

That's *why* individuals have to 'circumvent/trick' the engines normal "closed-loop" operational mode to make them "more efficient," by getting the ECM to operate closer to "lean" A/F ratio (16-18:1) than the 'chemical correct' stoichiometric (14.7:1) ratio needed for EPA requirements and catalytic converter "longivity."
Yes thanks for clarifying. I was aware of this already as I know stoich does fluctuate and sometimes other air fuel ratios are targeted but other readers will find this useful to know.
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