My C63 is bone stock (except for some minor exhaust work with secondaries and resonator), but otherwise stock.

Lately, it has been 95+ with high humidity and the car still feels powerful here and there, but it is noticeable enough to notice the power loss.

Does anyone else experience this? Is it constant or just on extreme heat days? I never noticed it until recently this summer (had car ~9 months).

I doubt the exhaust work has anything to do with it, it is a noticeable power loss like the motor doesn't want to go like it did in the cooler months.


Thank you for any feedback,

You're experiencing something called physics and it's completely normal.

2 things. 1) your car is making less power as stated above. No way around that. 2) your car has more grip and feels slower. In the winter when you car does the opposite, it definitely feels faster when the back end is more willing to dance around.

Yep, this is completely normal.

I'm in Hong Kong, so, it's humid as all hell and hot as ***** during the summer. The car definitely doesn't run as powerful as it does when it's in the Fall/Winter.

The cooler the temps, the more dense the air. The physics mentioned above. More air in the combustion cycle creates a better fuel burn which enhances engine performance.

lol here in London we don't have that problem.

It's miserable and dreary and grey here all year round, bar a few days!

Also I'd add that if it's that hot you probably have the AC running which is known to drain some of the power in spurts.