Quote:
Originally Posted by Cobb
People want power, lean burn doesnt offer that.
With direct injection coming out the afr is really a moot point.
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Not really, as the Air Fuel Ratio (AFR) is still the ratio of AIR-to-GASOLINE, except with Direct Injection (DI) it occurs *instantly* within the cylinder when the injector pintle opens and injects a specfically-metered amount of GASOLINE into the compressed AIR inside the cylinder...it's still a ratio.
With DI, AFR can become more dynamic, but only *IF* the Engine Control Module (ECM) "brain" is smart enough to make "right" changes rather than just "some" changes...which boils down to intelligent algorithms and software/firmware inside the ECM. Thus,
some manufacturers will have it,
some won't.
The *problem* comes back to what's coming OUT of the exhaust pipe, and DI (as currently implemented) has been shown to INCREASE exhaust particle pollutants...and, particles "plug" catalytic converters.
And, NOx scrubbing isn't currently *up* to meeting current EPA emission requirements, much less, the anticipated FUTURE requirements coming down the pike. So, *lean-burn* (AFR ~ 16-18:1 or more) is not likely to come-back soon, without new break throughs in both DI and catalytic converters...ie: probably something like urea purge injection, etc.