2020 Porsche Cayenne tire size

Most common factory size

P285/40R21

Tire sizes by trim

Source marks: one source

2020 Porsche Cayenne tire size by trim
Size	Trims	Width, mm	Sidewall, % of width	Rim, in	Diameter, in	Sidewall, in	Revs per mile
P285/40R21	Turbo AWD, Coupe Turbo AWD, Turbo S E-Hybrid AWD, Coupe Turbo S E-Hybrid AWD	285	40	21	29.98	4.49	673
P255/55R19	AWD, E-Hybrid AWD, S AWD	255	55	19	30.04	5.52	671
P275/45R20	Coupe AWD, Coupe E-Hybrid AWD, Coupe S AWD	275	45	20	29.74	4.87	678

What P285/40R21 means
Part	Number	Meaning
Type	P	Passenger car tire.
Width	285 mm	Tread width. 11.2 in.
Sidewall	40	Sidewall height is 40% of the width.
Construction	R	Radial tire.
Rim	21 in	Fits 21 in wheels.

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

Sizes within 3% of P285/40R21
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
255/40R22	22	30.03	+0.2%	59.9 mph
255/45R21	21	30.04	+0.2%	59.9 mph
255/50R20	20	30.04	+0.2%	59.9 mph
285/35R22	22	29.85	-0.4%	60.2 mph
285/45R20	20	30.10	+0.4%	59.8 mph
235/55R20	20	30.18	+0.7%	59.6 mph
275/45R20	20	29.74	-0.8%	60.5 mph
235/50R21	21	30.25	+0.9%	59.5 mph

Sizes within 3% of P255/55R19
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
255/60R18	18	30.05	+0.0%	60.0 mph
255/50R20	20	30.04	-0.0%	60.0 mph
235/65R18	18	30.03	-0.1%	60.0 mph
285/45R20	20	30.10	+0.2%	59.9 mph
235/60R19	19	30.10	+0.2%	59.9 mph
235/55R20	20	30.18	+0.4%	59.7 mph
275/55R18	18	29.91	-0.4%	60.3 mph
275/50R19	19	29.83	-0.7%	60.4 mph

Sizes within 3% of P275/45R20
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
245/45R21	21	29.68	-0.2%	60.1 mph
275/50R19	19	29.83	+0.3%	59.8 mph
275/40R21	21	29.66	-0.3%	60.2 mph
245/50R20	20	29.65	-0.3%	60.2 mph
225/60R19	19	29.63	-0.4%	60.2 mph
245/55R19	19	29.61	-0.5%	60.3 mph
285/40R21	21	29.98	+0.8%	59.5 mph
255/45R21	21	30.04	+1.0%	59.4 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.