Ive been doing some reading to try and make myself a little smarter.. but i think ive just confused myself a little more.. theres loads of questions and technical stuff ive got buzzing around in my head but im gonna make it simple so i dont get even more confused!!

Cold air intake: Increased air density means that more fuel can be added to equalize air:fuel ratio = More power

Warm air intake: Decreased density which intentionally depowers the car meaning the throttle will be opened wider therefor reducing pumping losses (which im guessing means that the engine has more efficiency per stroke) = more MPG

This is just a guess based on what ive read...

tell me if im wrong and please do enlighten me on the subject, i understand its under some controversy and has been for a while now...

heres my arguement: CAI would give more power meaning you wouldnt have to accelerate as much to get the same power therefore increasing efficiency and MPG?

i dont know much about WAI and have no idea what pumping losses are (like i said i had a guess at what it was above)

GO!!!!

Just come accrss this. WAI ? not really seen it termed like that. But no big stumbling block. Warm air into the engine usually decreases perfomance and economy , cold air usually increases performance and economy. It's all about air on the inlet side of the engine. Colder , denser air has more oxygen , than warm air. So in colder air you get a bigger bang , than warmer air. All the engine is doing is igniting air and fuel. This is all in simplistic terms of course , it can get really complicated when other factors are concerned. Buy don't need to worry about it.

You might have noticed yourself if you drive on warm day , your car feels o.k. Then later in the colder evening the car feels a little more energetic , a bit quicker. That's the effect of colder denser air.

As regards the WAI and reduced pumping losses and wider throttle openings is a contradiction as with wider throttle opening usually means more fuel , with more fuel comes poor economy as more fuel needs more air ( more oxygen in fact ) so it does not add up. The only time warm is ever good is on the startup cycle of an engine in cold climates.

There is a thing called the stoichiometric ratio , or more commonly know as air to fuel ratio ( for this instance ) this determines how efficiently fuel is burned in air. It's trying to maintain this ratio that we strive for for both econommy and perfomance. It's massive area of debate and a lot of science.

So simply for us mere mortals , cooler air usually better for your engine than warm air. Hope i have not confused you more.