I'm going to buy and run for the first time a winter rally spiked tyre of 145 80 r13, and I was wondering what pressures do people generally use rallying in low winter temperatures on snowy terrain?
Does running a low pressure increase the grip? Does the air inside increase or decrease volume just like a summer tyre increase pressure inside it as it gets warm?
Note: I am asking about a rally tyre, not a road one
Edit: The manufacturer recommended 1.5bar front and 2.0bar for rear (2.5bar for high oversteer) for my current setup, fwd light car with 75% weight on front