Setting the temp at 90 degrees does not cause the truck cab to warm up faster.

On the way up from zero to 90 degrees, when it hits 75 it hits 75. Setting it to 80000 degrees would not get it to 75 any faster.

 

Koolaid:

It sounds to me is like you are describing the AUTO MODE where the thermostat works like one in a house.

I'm not sure how your truck's A/C works but when you set the temp in mine to 90 the air coming out is a helluva lot warmer than if it's set at 60.

So lets see...If the air coming out is warmer...that equals less time to heat the cab.

 

Yes.....Auto Mode.

Are you talking about after the water is already hot?

Mine doesn't start blowing until the water is hot. When it does start blowing, with it set at 70, it takes a matter of seconds, or maybe a minute to warm the cab. The fan is variable speed. It blows fast at first then slows down as the cab warms up.

If the original poster doesn't want the hassle of having to change the temp from 90 to 70, then just leave it on 70.

 

Im with Kool Aid....my temp setting rarely leaves 60. This morning it was 44 outside and I had the climate control on 60....

 

I don't instantly heat up as soon as my cab does.

My hands are often cold and almost numb and it feels better to have warm air blowing on them even after the cab is already at 70 degrees.