[pete c]

this ought to go over like a lead zeppelin over at FRF.

CAI don't work on any gasoline engines regarding mpg. In fact, just the opposite, warm air intakes, improve mpg.

I realize this seems counterintuitive because CAI may improve peak hp, but, it all comes down to pumping losses. Internal combustion engines are inefficient beasts. Part of this inefficiency is due to the means it uses to control power, a throttle. A throttle controls OP by restricting air flow, or more importantly oxygen flow. This is called a pumping loss and it is substantial. Diesels have higher efficiency partly because they control power by limiting fuel, not air. Therefore, they don't have this loss.

A CAI works by supplying colder, denser, more oxygen rich air. The result is the engine makes more power, which means you must close the throttle some for the desired power output. And the result, from an engine efficiency viewpoint is lowered efficiency due to increased pumping losses.

This does not apply to carbureted engines. They ain't smart enough to detect oxygen content. They monitor fuel strictly by airflow, rather than oxygen flow. A CAI will simply result in the engine running a little richer.

CAIs definitely do help diesels. Turbos help diesel efficiency too, unlike gassers. It is why every single big rig on the road today has one.

For those that may dispute this, take a look at your mpg numbers in the winter. Part of the drop is due to pushing your truck through denser air, part is due to the fact that we all run CAIs when it's 20 degrees out.

And yes, "that ought to go over like a lead zeppelin" is how the greatest band in history came about its name. It was said by Keith Moon.