Quote:
Originally Posted by Old Tele man
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.
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My 96 civic with vx drivetrain didn't make enough power in lean burn to maintain 65mph, only about 55-60 with careful attention to the gas pedal. Albeit, a 92-95 hatch had better aero and probably does maintain 60-65mph in lean burn.
Anyways, I drive a jetta tdi now. Aren't all diesels lean burn? Do they have high NOX? And with urea purge injection, could you take a gas lean burn engine and reduce its NOX to a safe level? I think you get direct injection with lean burn and hybrid setup and you're set. ......wait, that's what the first gen insight was right?
