Why do big engines like cool & wet?

[lloyd3]

I've driven the car a couple of times since the suspension repair last week and I noticed lots of good things. No clanking and banging when I go over bumps, noticeably better handling overall (surprise!) and....the cooler (& wet) weather of late really seems to make this old stock block very happy.  I used to notice this back in the "old days" as well. Cooler spring and fall weather made for a noticeable uptick in performance on my various big-block cars.

Is the answer obvious or is there more to it? You wouldn't think just a few degrees and a little humidity would make such a noticeable difference. It never seemed to be a factor on any other cars that I've owned & driven, just my muscle cars. 

[Cncguy]

Because in cool weather the fuel has more time to reach the cylinders before it vaporizes?

[Alaskan_TA]

Cooler air is denser than warm air, so it aids with combustion.

[Lennard]

An engine is a big air pump.  Cooler air is denser than warm air so more air fits in the cylinders and more air and more fuel = more power.

[myk]

Driving at night it's like a different car...

[cbrestorations]

Turbo cars are pretty Consistent, turbo just has to work a little harder in the heat

[Chargerguy74]

Deleted. Lennard nailed it.

[lloyd3]

I think Lennard did nail it, but I was wondering if the humidity was a factor as well. We're normally pretty dry out here, and on the rare occasions when the roads are dry but the air is damp(!) it seems to help a little too.  Sort of like how water injection helps with controlling flame-front propagation?

[plum500]

This might interest you...

http://www.madsci.org/posts/archives/2000-04/955052253.Eg.r.html

[Chargerguy74]

That's interesting. Water can expand in volume 1700 times when it flashes to steam.

[68X426]

What happens to steam engines on a hot humid day? 

[6spd68]

Driving at night it's like a different car...

Is there really a better time to drive a nice/fast car?