[tirwin]

The air density is going to be less, but other than pulling over and adjusting the idle screw when you get to altitude, I don’t know what else you could do to compensate. Especially on a temporary basis since you’ll be coming back down.

I’d pull over at a gas station, raise the idle and check your tire pressure.

You’ll need to dial the idle rpm back down of course when you get back to sea level.

PS - I’m assuming the car is in good tune. No vac leaks or other issues.