[LeanBurn]

SRI = short ram intake. Sometimes set up like a warm air intake. Its not a cold air intake at all but intakes air usually from directly beside the engine the shortest path. Not sure where the "RAM" part comes into play, probably more marketing than anything else. I have tested these and temperature variations fluctuate wildly as at rest it sucks up hot air radiating from the engine and radiator, then as one gets to speed it begins to fall.

CAI = cold air intake...obviously already covered. The object is not to intake air from air supply down lower than the engine, or any other altitude relation to the engine. It is intended to draw air temps as close to ambient air found outside the engine bay as possible. Often this means putting the intake end as far away from the engine as possible and where a filter will fit if an entire replacement set up is used. Consequently this often means putting the intake opening/filter behind the front bumper under the headlamp. temperature variations are minimal nearly constant as far as the intake tube/tract is heated by surrounding air. CAI Hydro-lock concerns are only realized when idiots roll through water that is deep enough to immerse the intake filter element and it sucks it up like a straw. For the rest of those that avoid water that is 12 inches deep or more as pure common sense, it is never an issue.

Interesting to know that there are quite a few CAI from factory, My 1997 Suburban has one, there are even some ram cold air intakes (which puts the cold air intake directly in the airflow like those found on the new Insight.

Some cars it makes little to no difference with regards to fuel economy whether CAI or WAI (SRI). There is some difference in power in some engines...which has been covered.