How do you use pit stops?

[ObiQuiet]

The simple answer:
When your car meets the conditions, there's a banner at the top of the screen that appears asking if you want to do a pit stop. Buttons for yes or no.

[Xtoff06]

You have to stop your car in Gear 1 and it's automatic if you need (changing weather or mechanic problem )

If you need ? People said that you can stop without need. (Because sometimes you want to end in speed 0 rather than 1)

"If you need" is understood as inclusive of "if you want"

if you need is if the car need not if you want
like say Obiquiet :
"When your car meets the conditions" is a good wording
there's a banner at the top of the screen that appears asking if you want to do a pit stop.
Buttons for tire or mechanical or both