When it's cold - Why do car's perform better...?

Virdi

Virdi

Virdi

Soldato
Joined
11 Jun 2004
Posts
4,232
Location
Middlesex, London
Hi all,

As we all know - when it's cold outside - An engine responds better, hence, giving you more performance..

But what is the actual real scientific reason behind this?

...is it because the air is cold - hence the air being at low temperatue, gives you faster combustion? or better combustion?

....or is it because cold air is more dense - hence giving you more oxygen in the same amount of space - Hence making combustion more efficient?



Thanks
 
Generaly engines work better when kept cool but dont mistaken this for an engine that isnt warmed up. i woukldnt recoment jumping in your waggon and flooring it first thing in the morning on the way to work or we all know the outcome of that. if you do it to often.

Also Because cooler air has more density for a given volume than warm air. Turbo/Supercharged engines work so much better when the air is crisp aswell.

you will also find that after market Induction kits claim to make a difference whether they do or dont is a different argument but the over all principle is to get as much cold air into the engine as possible.

Hence why your cars air box is like a tunnel and usualy has an inlet point facing towards the front of the car. the faster you go the more airr that is forced in. Hence the term RAM Air.
 
For Turbo's cars with Intercoolers etc... - They probably have even more affect - As not only is the air coming in colder - But also the air hitting the Intercooler is colder as well...
 
DavieCramb01 said:
Hence why your cars air box is like a tunnel and usualy has an inlet point facing towards the front of the car. the faster you go the more airr that is forced in. Hence the term RAM Air.
Click to expand...

They point forward simply to pick up cool air, you don't get any "ram air" effect until you hit speeds that most cars aren't capable of. You can get the generate about 0.18 PSI over atmospheric pressure at 100mph, and you have to be doing over 200mph to generate 1 PSI. Useful in an F1 car, not so great for your average road car.
 
Presumably (perhaps to a lesser extent) the fuel is denser as well and so you would get a greater amount of energy per unit of fuel.

Isn't that why its best to refuel in the early morning when the fuel is at it's most dense?
 
I think, as mentioned, it's because the air is more dense, hence more oxygen by volume, which means more fuel can be added, and a larger explosion ensues.. as simple as that!
 
Dogbreath said:
You can get the generate about 0.18 PSI over atmospheric pressure at 100mph, and you have to be doing over 200mph to generate 1 PSI. Useful in an F1 car, not so great for your average road car.
Click to expand...

Helps a nice bit on the bike though as over 100mph is where the bike's aeordynamics suck big time. Every little extra bit of power goes a long way from 100mph up. Of course we're talking about 170mph bikes here so not on par with your average road car. :P
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom