Actually, if less air = less fuel, it wouldn't be lean, it would just make less power...

but overall, yes, cold air is more dense, which means more air overall in comparison to hot air...

 

Not starting a war, but on an LH-Jet system, PCM can compensate the fuel trim. But on an L-Jet system, yes you will lose power because it can't compensate for the loss. In addition, a car going up to higher elevation, you get less air so it will get less fuel, that's why the car pings because its running lean.

 

You are talking about the old school vane type, movable flap air meters... those things were/are terrible... that system should have never been used on a passenger car... (funny that the Europeans were the ones to use it more than anyone else)

On a normal car (mass air flow either karman vortex or hotwire, or map based with a temperature input) the system can account for the higher elevation or lack of air and still provide the appropriate amount of fuel so that the system does not run lean. Even then, the O2 feedback would show, even if it was running lean, and the PCM would add fuel to compensate. I've never had any vehicle ping or knock at high elevation...

 

good read...thanks for the info as this applies to the 3IS as well

 

Good information to know. Thank you.

 

nice to see that not everyone buys into the BS narrative that a short and "cold" air intakes actually provide any cold air.... Common sense and 101 engineering level examination of a car engine bay reveals that that idea will only work if that CAI is mounted OUTSIDE of the car. when it is stuck inside of the bay sucking in hot air warmed by the engine, there will be nothing cold about it by the time it hits the cylinders...