is it just me or does cars run quicker when cold?

[R9 PUG]

maby its in my head but after say driving around the town for a while the throttle responce seems a bit sluggish compared to when u first get in the car that day, aceleration and so seems alot sharper when the cars cold is it in my head or is this realy hapening lol

[kenich]

I dont tend to rag my cars when there cold myself... Or do you mean outside?

[R9 PUG]

i dont mean the air temp and i dont mean thrashing it when stone cold, i mean like 10 mins or 15 after ur newly in it it

[jon_ox]

cold air temps are better for the car it creates a better mixture i think, i could be wrong though!

[Dave Y]

some boffin will come on and explain exactly but jon is right.

[VTR turbo]

colder ai ris denser so the colder the air the more air you get in the engine at combustion giving a bigger bang, hench why bigger intercoolers are better for turbo cars and its the same principle for nitrous

[cobblers]

When cold, there are more air molecules per litre, so the car puts more fuel in and basically gives you the equivalent of a slightly larger engine.

If I had more time on my hands, I would work out exactly how much difference it makes.
The altitude you are at also makes a difference, so at 9000 feet on a hot day your car is barely going to move, but drive into a valley in on a freezing day and it will shift.

http://en.wikipedia.org/wiki/Density_of_air

[Jimmers]

Plus, theres the simple fact that colder inlet air will stay cooler in the engine, is more dense, as stated above, and thus, more fuel can be injected, ergo more power!

Thats why I like my new dynofiend gasket kit, inlet is usually stone cold on motorway runs! :veryhappy:

[Dobber Sport]

i dont mean the air temp

yeah cars have a cold start mode which puts more fuel into the engine, (also know as a automatic choke)) but you should NEVER boot a engine from cold, it dramatically reduces their life.

in addition the cheap "chips" you get on Ebay etc just trick your car into thinking its always cold so it always adds more fuel.

[G-Dub]

I've been thinking the exact same thing recently, and I also think my car sounds better when it's cold outside