Red Lining

[Water Warrior 2]

Originally Posted by Nightsbane

I wanted to add that outside the wind as a resistant, the roads are 99% totally flat. Right now my main concern is the sudden change in engine sound. It is much cooler outside tonight as well for the first time in two months. Just trying to figure out if I have a problem or if I broke something with highway driving...

I think you have the answer in front of you. Much cooler air will make a difference because it is denser air. You have denser air going into the engine and you are hearing with denser air around your ears.