2021 Cadillac CT4 tire size

Most common factory size

P235/40R18

Tire sizes by trim

Source marks: one source

2021 Cadillac CT4 tire size by trim
Size	Trims	Width, mm	Sidewall, % of width	Rim, in	Diameter, in	Sidewall, in	Revs per mile
P235/40R18	Premium Luxury RWD, Sport AWD, Premium Luxury AWD, Sport RWD, V-Series RWD, V-Series AWD	235	40	18	25.40	3.70	794
P235/35R19	Luxury RWD, Luxury AWD	235	35	19	25.48	3.24	792

What P235/40R18 means
Part	Number	Meaning
Type	P	Passenger car tire.
Width	235 mm	Tread width. 9.3 in.
Sidewall	40	Sidewall height is 40% of the width.
Construction	R	Radial tire.
Rim	18 in	Fits 18 in wheels.

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

Sizes within 3% of P235/40R18
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
215/50R17	17	25.46	+0.2%	59.9 mph
235/35R19	19	25.48	+0.3%	59.8 mph
235/45R17	17	25.33	-0.3%	60.2 mph
205/45R18	18	25.26	-0.5%	60.3 mph
265/30R19	19	25.26	-0.6%	60.3 mph
275/35R18	18	25.58	+0.7%	59.6 mph
225/35R19	19	25.20	-0.8%	60.5 mph
215/45R18	18	25.62	+0.9%	59.5 mph

Sizes within 3% of P235/35R19
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
235/40R18	18	25.40	-0.3%	60.2 mph
275/35R18	18	25.58	+0.4%	59.8 mph
215/45R18	18	25.62	+0.6%	59.7 mph
205/45R18	18	25.26	-0.8%	60.5 mph
265/30R19	19	25.26	-0.8%	60.5 mph
245/40R18	18	25.72	+0.9%	59.4 mph
285/30R19	19	25.73	+1.0%	59.4 mph
225/35R19	19	25.20	-1.1%	60.7 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.