1978 Cadillac Seville tire and wheel sizes, bolt pattern and tire pressure

Bolt pattern 5x127 on every 1978 trim.

Tires for the 1978 Cadillac Seville

Sizes most trims come with first. Open your trim below for its exact size.

215/75R15 Best-rated standard on 2 trims

Check price on Amazon · 215/75R15
235/70R15 Best-rated optional on 2 trims

Check price on Amazon · 235/70R15
235/65R16 Best-rated optional on 2 trims

Check price on Amazon · 235/65R16

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Trims sold in 1978: 2
Generation: K-body I
Other years: 1975
1976
1977
1978
1979
1980
1981
1982
All years (1975–2004)

2 trims sold in 1978

Open a trim for its tire and rim sizes, bolt pattern and tire pressure. Trims with the same tires and wheels share a row.

Cadillac Seville K-body I

1975–1979 2 trims

Seville 5.7 +1 variant 174 hp · V8 215/75R15 99S 4 fitments

Same tires and wheels on: 5.7D

Generation: K-body I · 1975–1979
Power: 174 hp
Engine: V8, Petrol
Center bore: 78.1 mm
Bolt pattern: 5x127
Thread: 1/2" - 20 UNF

Check price on Amazon · 215/75R15 Wheels 15x6 ET13 · 5x127 · 78.1 mm on Amazon

Tire size	Rim size and bolt pattern	Pressure, psi
215/75R15 99S	Rim 15x6 ET13 ~~5x127~~	32 psi
235/70R15 99S	Rim 15x7 ET10 ~~5x127~~	32 psi
235/65R16 97H	Rim 16x7.5 ET5 ~~5x127~~	35 psi
255/55R17 95H	Rim 17x8 ET0 ~~5x127~~	36 psi

How to read 99S: 99 is the load index (up to 1,709 lb / 775 kg per tire) and S the speed rating (up to 112 mph / 180 km/h). ET13 is the wheel offset: how far the mounting face sits from the rim centre, in millimetres. Compare offsets in the wheel offset calculator.

What these columns mean

Rim size: Rim diameter × width in inches, and the factory offset (ET) in millimetres, e.g. 18x7.5 ET25.
Bolt pattern (PCD): Number of studs and the diameter of the circle they sit on. It must match exactly.
Center bore: Diameter of the hub hole. Larger aftermarket bores need hub-centric rings.
Pressure: Recommended cold inflation pressure for that axle, in psi.
Thread size: Lug bolt or nut thread — needed when buying aftermarket fasteners.