I have never felt my car pull like it did going to work today. I filled up with 93oct citgo, it was 73 deg and overcast it rained heavy the night before. It felt like it was an extra 30hp or more no joke.
Run 89-93 octane and regap those plugs!(For those who might ask, no mods, 87 octane, .025 gap - yes I've tried regapping, but it killed fuel economy and low end power).
High levels of humidity reduce the amount of oxygen in the air.I have noticed the same thing. I posted another thread about it.
The temps and humidity fluctuate a lot here in SF as the coastal fog rolls in and out.
When the fog rolls out, the temps go up into the 70s+ with a nice coastal breeze. The humidity drops, and my Cruze pulls like crazy. I only need to push the pedal down about an inch and it launches forward and pushes me back into the seat.
When the fog rolls in, the temps drop slightly, but the humidity goes up, and my Cruze seems to have less pull. It's still pretty good, but it doesn't launch forward as much when the turbo kicks in.
The first few days after I bought the car there was no fog and low humidity. It actually took a little time to get used to the launch effect. Then about a week later the fog rolled in and it seemed like it didn't have as much pull anymore. I didn't consider the weather, and I actually thought there might be something wrong with the car. I was a little worried that maybe I hadn't broken it in properly.
Maybe I should start logging temp, humidity and turbo pull to see what is ideal.