Been meaning to ask this for awhile...

I remember back in 2008 when I got my 06 TL, I noticed that on certain days, when the outside temperature would be anywhere from 60-65, dry and crisp, the engine would seem to perform better. You could feel it in the throttle response. The throttle and engine torque seemed much more responsive to the point where the car seemed like it was ready to crawl out of its skin. Ready to pounce and go without having to give it much throttle, as opposed to either warmer or colder temperatures.

I've noticed the J engine in the RLX seems to have this exact same characteristic under the same weather conditions. It's spring here in Atlanta and we've had some great weather as of late including the conditions I nentioned above, and the car has been like a rocket ship.

When I asked this question on Acurazine back when I had the TL, someone mentioned something to the effect that it was a known characteristic of the VTEC engine design and that there were optimal operating conditions in which the engine exhibited peak performance characteristic. But I can't quite remember the details.

Any one here know more about this? Just curious to get some insight.

Have a great morning!

 

It has to do with how much oxygen is in the air. That's why people add turbos and compressor to their car engines. To increase the amount of oxygen they can get into their combustion chamber. Likewise for nitrous oxide.

Below is an excerpt from HowStuffWorks? concerning oxygen and the internal combustion engine.

The internal combustion engine in most cars burns gasoline. To do the burning, an engine needs oxygen, and the oxygen comes from the air all around us. But what if cars carried their own and pumped pure oxygen into the engine instead?
The air around us is about 21 percent oxygen. Almost all the rest is nitrogen, which is inert when it runs through the engine. The oxygen controls how much gasoline an engine can burn. The ratio of gas to oxygen is about 1:14 -- for each gram of gasoline that burns, the engine needs about 14 grams of oxygen. The engine can burn no more gas than the amount of oxygen allows. Any extra fuel would come out of the exhaust pipe unburned.
So if the car used pure oxygen, it would be inhaling 100 percent oxygen instead of 21 percent oxygen, or about five times more oxygen. This would mean that it could burn about five times more fuel. And that would mean about five times more horsepower. So a 100-horsepower engine would become a 500-horsepower engine!

 

Yep, you aren't imagining this. It's not so much the V-TEC engine; cooler temperatures act a little like a cold air intake. Cooler air is more dense with oxygen and provides a tiny little bit more HP in the combustion chamber, and this will be true for most modern cars.

So enjoy your cool morning drives!

 

^ makes perfect sense. thanks for the insight guys.

 

It's not just Honda engines, it is basic physics of fuel combustion as noted above. Cold air is more dense. Therefore, more air available for combustion, and so more power.

An extreme case is my CTS-V. It is even more of a beast in cooler temps once the engine is at operating temperature.