mjr24

I have heard this.....but not sure if it's just a myth or not?

joshthorsc

I've heard this as well. My cars feel less sluggish on cold days compared to hot days like during summer.

~Josh

rominl

iTrader: (4)

technically that's true coz' air is cooler so it's denser

really? i don't feel that much of a diffference between hot summer and cold winter here

AJ

I feel it everyday since the weather jumps from 78F(6 am) to 118F(noon) .

Och

iTrader: (3)

Shouldn't be a major difference. Maybe a quicker responce in cold weather, but the acceleration at WOT should be around the same. One thing to keep in mind, when its hot out most people are running AC, which robs away a few horses.

O. L. T.

iTrader: (17)

ummmm.... anyone ever heard of a cold air intake?

mmarshall

That's because SoCal, at low elevations, doesn't HAVE a winter.


Most engines will in fact create more HP and torque in the winter due to the colder, denser air containing more oxygen for combustion and the computer feeding in more gasoline to maintain the correct air-fuel ratio. However, you will notice this more after the engine warms up a little.....cold oil ( conventional oil more than synthetic ) will put a marked drag on the engine, transmission, and differentials. ( and you don't want to run a cold engine hard anyway ).

This is one of the ways a turbo or supercharger works....at warm air temperatures, it artificially makes the engine perform like one at colder air temperatures by force-feeding the engine with more fuel and air that it would normally burn at that air temperature and pressure.

Same with altitude.......rising altitude has the same effect as warmer air temperatures despite the colder air, because the air gets thinner as you go up.....3% for each thousand feet on the average. So a good turbo keeps the engine operating as it would at sea level up to a certain altitude...known as the critical altitude. This is a factor in the design of airplanes.

plex

iTrader: (11)

There is a noticeable difference with my car in the cooler temperatures. The turbos love cooler air.

GSsnarl

Sound like a job for the Myth Busters?

Lexmex

Anyone ever hear of an intercooler? There is a reason it exists.

Not a job for mythbusters. Every weekend I put my little RX down on the track and run it, we have a little weather station (see below) that measures air temp, air pressure and humidity. The lower the air temp and humidity and the higher the pressure, the faster my little RX will go, however the air temp has the biggest effect.

When I run my RX, I always check and note the readings on this little device we sit on the windowsill of the control tower.

Now, I also feel the effects of high altitude, 7,411 feet is the track elevation, and we generally have 23% less oxygen up here than at sea level.

rosskoss

Power is a function of airflow. Cold air is more dense and there are more air molecules to combine with fuel to generate more power.

rominl

iTrader: (4)

well, if you say 30s isn't cool enough for winter

rai

It is not open to debate, lower temp means more power as has already been said.

But lower temp means tires do not grip as well, so you may find if it's too cold you won't necessarly go any quicker.

Also it is very dependent on the type of car and engine and what type of power you are making to begin with.

I can also feel the difference in tire grip in very hot weather. When it's 100 degrees out the car feels like it's stuck to the road.

I can tell here in MD, some winter days it's below zero and summer days it's over 100 degrees that's a huge temp difference. If you are in a temperate climate you may not even notice the difference.

But def, yes when it's super cold the car will have ++ HP no question about it.

4TehNguyen

iTrader: (1)

its faster because im not using the A/C

doug_999

I can't believe we are even discussing this. Worse, I can't believe there are people who think it doesn't make a difference!