I have a weird question or it seems weird to me, maybe common to you all but my truck runs better and has more power in cooler weather.. It has cooled off here . It's 45 -50 in the mornings and its a big difference in the way it ran over the summer.. I thought i noticed last year and now I'm SURE it has alot more power in cooler weather.. Any ideas......WHY?

 

Cooler air is more dense and has more oxygen in it. The ECM compensates for that and richens up the mix a little to compensate, and what you end up with is an engine making more power. They definitely run better in the cold, no doubt about it.

 

Cooler Air = More power

Thats why cool air intakes are made to add performance to engines.

There was a thread a couple weeks ago that had people debating whether drilling holes in your airbox so it can suck in more air did more harm than good because instead of sucking in cooler air near the headlight it was sucking in 150 degree or warmer engine compartment air.

 

Like the others have mentioned, it is due to the air being more dense in the winter for two reasons...

1) because it is colder (cold air is more dense than warm air)
2) because it is more dry (lower humidity air is more dense than higher humidity air)

The other way to increase intake air density is by increasing its pressure, which is how superchargers and turbochargers help a vehicle produce more power.

Higher density intake air = higher power, why? Because there is more oxygen available for the combustion process, which allows for more fuel to be burned. Same idea as a NOS injection system... it provides extra oxygen to allow more fuel to be burned, which in turn will produce more power.

Another thing to keep in mind though, is that higher density air increases the drag on your vehicle as well, which works against the gains in power the higher density air provides.

Hope this helps.

 

Take the EGR off and experience part of that in the summer
Heat Heat Heat , thats why
Ding Dang Heat

 

Cold air =