2020 Audi S5 tire size

Most common factory size

P265/30R20

Tire sizes by trim

Source marks: one source

2020 Audi S5 tire size by trim
Size	Trims	Width, mm	Sidewall, % of width	Rim, in	Diameter, in	Sidewall, in	Revs per mile
P265/30R20	Premium Plus AWD, Prestige AWD	265	30	20	26.26	3.13	768
P255/35R19	Premium AWD	255	35	19	26.03	3.51	775

What P265/30R20 means
Part	Number	Meaning
Type	P	Passenger car tire.
Width	265 mm	Tread width. 10.4 in.
Sidewall	30	Sidewall height is 30% of the width.
Construction	R	Radial tire.
Rim	20 in	Fits 20 in wheels.

Within 3% of the stock diameter. A common shop guideline, not a maker spec.

Sizes within 3% of P265/30R20
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
265/35R19	19	26.30	+0.2%	59.9 mph
305/30R19	19	26.20	-0.2%	60.1 mph
225/35R20	20	26.20	-0.2%	60.1 mph
235/40R19	19	26.40	+0.5%	59.7 mph
225/40R19	19	26.09	-0.7%	60.4 mph
235/35R20	20	26.48	+0.8%	59.5 mph
255/35R19	19	26.03	-0.9%	60.5 mph
255/30R20	20	26.02	-0.9%	60.5 mph

Sizes within 3% of P255/35R19
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
255/30R20	20	26.02	-0.0%	60.0 mph
255/40R18	18	26.03	+0.0%	60.0 mph
225/45R18	18	25.97	-0.2%	60.1 mph
225/40R19	19	26.09	+0.2%	59.9 mph
225/35R20	20	26.20	+0.7%	59.6 mph
305/30R19	19	26.20	+0.7%	59.6 mph
265/30R20	20	26.26	+0.9%	59.5 mph
245/30R20	20	25.79	-0.9%	60.6 mph

Checked against 292 factory sizes listed for 2009-2027 US models.

Tire pressure is on the driver door sticker. Not in this data.

Optional wheel packages may differ.