2026 Cadillac OPTIQ tire size

Most common factory size

P245/50R20

Tire sizes by trim

Source marks: one source

2026 Cadillac OPTIQ tire size by trim
Size	Trims	Width, mm	Sidewall, % of width	Rim, in	Diameter, in	Sidewall, in	Revs per mile
P245/50R20	Luxury RWD, Sport RWD, Premium Luxury AWD, Premium Luxury RWD, Premium Sport AWD, Premium Sport RWD +2 more	245	50	20	29.65	4.82	680
P275/40R21	4dr OPTIQ-V AWD	275	40	21	29.66	4.33	680

What P245/50R20 means
Part	Number	Meaning
Type	P	Passenger car tire.
Width	245 mm	Tread width. 9.6 in.
Sidewall	50	Sidewall height is 50% 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 P245/50R20
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
275/40R21	21	29.66	+0.1%	60.0 mph
225/60R19	19	29.63	-0.1%	60.0 mph
245/45R21	21	29.68	+0.1%	59.9 mph
245/55R19	19	29.61	-0.1%	60.1 mph
275/45R20	20	29.74	+0.3%	59.8 mph
275/50R19	19	29.83	+0.6%	59.6 mph
265/50R19	19	29.43	-0.7%	60.4 mph
265/45R20	20	29.39	-0.9%	60.5 mph

Sizes within 3% of P275/40R21
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
245/50R20	20	29.65	-0.1%	60.0 mph
245/45R21	21	29.68	+0.1%	60.0 mph
275/35R22	22	29.58	-0.3%	60.2 mph
275/45R20	20	29.74	+0.3%	59.8 mph
285/35R22	22	29.85	+0.7%	59.6 mph
265/45R20	20	29.39	-0.9%	60.6 mph
265/40R21	21	29.35	-1.1%	60.6 mph
285/40R21	21	29.98	+1.1%	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.