Wet grip and pressure

A correctly inflated tyre puts a designed patch on the road. Under-inflation grows the shoulders and can let the centre ride high, which is the opposite of what you want in standing water.

Over-inflation shrinks the patch to a skinny centre rib. On a wet roundabout that rib is the only thing steering. Neither extreme is “more rubber on the road” in a useful way.

Tread depth still matters. Pressure will not invent sipes on a 1.6 mm tyre in an October downpour.

Aquaplaning speed falls when pressure is low because the tyre cannot clear water as designed. If you must drive standing water, placard pressure and sensible speed beat a guess.

Winter compounds at the correct bar will outperform summer tyres at a made-up low pressure in the wet cold. Fit the right tyre, then inflate it properly.