Cadillac · STS · Bar

Cadillac STS tyre pressure in bar

Drivetrain: front-wheel drive
Body: passenger car
PSI F / R: 32-35 / 32-35
Bar F / R: 2.2-2.4 / 2.2-2.4

bar

2.31 / 2.31

32-35 / 32-35 psi · 231 / 231 kPa

32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa

2.3 bar is not 23 psi. On this STS 2.2-2.4 bar converts to about 32-35 psi. Use the table, not a guess. Under-inflation cooks the shoulders of a STS; over-inflation wears the centre rib and bangs every cat’s eye.

Bar, PSI and kPa

Bar-led conversions around the Cadillac STS. 2.2-2.4 bar is not “32-35 divided by ten”.

Bar	PSI	kPa
2.07	30	207
2.21	32	221
2.28	33	228
2.31	33.5	231
2.41	35	241
2.48	36	248
2.62	38	262
2.76	40	276
3.03	44	303
3.45	50	345
4.14	60	414

Cadillac STS placard versus sidewall

Sidewall PSI is a carcass maximum. Recommended operating pressure for this STS is the pillar sticker, near 34/34 psi.

Estimated pressure by tyre size (205/60R16 and others)

205/60R16 is the first planning size here. 225/45R17 is usually the plus-size or LT step. Keep load index at or above original equipment.

Tyre size	Front PSI	Rear PSI	Front bar	Rear bar	Front kPa	Rear kPa	Note
205/60R16	34	34	2.34	2.34	234	234	Taller 16-inch
225/50R17	35	35	2.41	2.41	241	241	Touring 17-inch
225/45R17	35	35	2.41	2.41	241	241	Sport 17-inch
215/55R16	34	35	2.34	2.41	234	241	Slightly wider 16-inch
185/65R15	33	33	2.28	2.28	228	228	Small / older car
195/65R15	34	34	2.34	2.34	234	234	Very common compact
205/55R16	34	34	2.34	2.34	234	234	Typical mid-compact OEM
215/50R17	35	35	2.41	2.41	241	241	Plus-size 17-inch

Load notes

Load moves the rear of a passenger car first. If the factory placard already has a “laden” column, use that instead of these sketches.

Condition	Front (est.)	Rear (est.)
Driver only	34 psi / 2.34 bar	34 psi / 2.34 bar
Full occupancy	35 psi / 2.41 bar	36 psi / 2.48 bar
Motorway + luggage	36 psi / 2.48 bar	37 psi / 2.55 bar

How to set the STS

Measure before the school run, not after the M25.
Write LF / RF / RR / RL. Do not keep STS numbers in your head.
Add air in short bursts toward 34 psi (2.31 bar) front and 34 psi rear.
If one corner is 4 psi down, hunt for a nail before you blame the weather.
Log date, ambient temperature and the four readings.

Temperature drift

Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this STS.

Ambient	Gauge (front mid)	Bar	kPa	Note
−5 °C (hard frost)	31 psi	2.14 bar	214 kPa	Gauge reads low; do not overfill once warm
0 °C	32 psi	2.21 bar	221 kPa	Gauge reads low; do not overfill once warm
8 °C (UK winter morning)	33 psi	2.28 bar	228 kPa	Gauge reads low; do not overfill once warm
20 °C (set cold here)	34 psi	2.34 bar	234 kPa	Baseline
30 °C	36 psi	2.48 bar	248 kPa	Do not bleed a hot tyre
38 °C (heatwave tarmac)	37 psi	2.55 bar	255 kPa	Do not bleed a hot tyre

Cadillac notes

No special Cadillac exception: the STS uses the door-pillar placard. Size estimates on this page only help if you have left the original load index behind.

Spare and inflator kit

A matching full-size spare on the Cadillac STS usually follows the higher axle (often the rear, near 32-35 psi). A space-saver is commonly 60 psi / 4.1 bar — read that tyre’s own sidewall. An inflator kit is not a spare; check the sealant date.

If the Cadillac sticker and this page disagree, the sticker wins.

Other Cadillac models

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Questions about this STS

What is that in bar and kPa for the STS?

Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.

What PSI if I plus-size toward 225/45R17?

Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 205/60R16, 225/50R17 and 225/45R17 as a planning band.

How often should I check a STS?

Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.

Is the sidewall number correct on a Cadillac STS?

No. Sidewall PSI is a maximum. The STS placard is the operating target, near 32-35/32-35 psi.

What tyre pressure should a Cadillac STS use?

Catalogue reference is 32-35 psi front and 32-35 psi rear (2.2-2.4 / 2.2-2.4 bar), cold. Confirm on the door-pillar placard.

Handbook: placard · bar vs PSI · front vs rear · cold inflation