Louvered hood sides

[Learpilot]

I got a question. Is there any difference in cooling of your engine or under hood temps  with smooth hood sides or louvered sides. I have always have run louvers or no hood sides.
Thanks, Rick Harris.

[enjenjo]

From my experience, yes, the smooth sides hold in more heat.

[timkins]

I got a question. Is there any difference in cooling of your engine or under hood temps  with smooth hood sides or louvered sides. I have always have run louvers or no hood sides.
Thanks, Rick Harris.

My car ran about 25 degrees warmer on the way to the Syracuse Nat's with the hood side on, and that was at 65 mph on the NYS Thruway.