FRENES

Wheels from Cadillac Seville on Pontiac Firebird: compatible?

Yes, with hub centric rings

Same 5x120.65 PCD, but the centre bore of the wheels from Cadillac Seville (78.1 mm) is larger than the hub of Pontiac Firebird (70.3 mm): you need 4 hub centric rings 78.1 → 70.3.

Rings 78.1 → 70.3

Cadillac Seville1975–1979Pontiac Firebird1982–1992
PCD5x127 / 5x120.65 / 5x1155x120.65
Centre bore78.1 mm70.3 mm
ThreadEcrous - 1/2 - 20 UNEcrous - 12x1.50
Original wheels ≈6.5Jx14 ET43
≈6.5Jx15 ET10
≈7Jx16 ET51
≈7.5Jx16 ET51		 R
≈6.5Jx14 ET12
≈7Jx16 ET45

≈: width estimated from the original tyre size.

Wheel by wheel: offset and tyres

Each original wheel from Cadillac Seville is compared with the one from Pontiac Firebird of the same diameter: how much closer the wheel gets to the shock absorber or how far it sticks out of the wheel arch, and whether the tyre keeps the same overall diameter.

  • ≈6.5Jx14 ET43 · 205/75R14 — Check on the car

    Compared with the original ≈6.5Jx14 ET12 on Pontiac Firebird: shock absorber side +31 mm, wheel arch side −31 mm, tyre diameter +0 %. Comparison for guidance only (estimated width). Check in detail

  • ≈7Jx16 ET51 · 225/60R16 — Check on the car

    Compared with the original ≈7Jx16 ET45 on Pontiac Firebird: shock absorber side +6 mm, wheel arch side −6 mm, tyre diameter +1.8 %. Comparison for guidance only (estimated width). Check in detail

  • ≈7.5Jx16 ET51 · 235/60R16 — Check on the car

    Compared with the original ≈7Jx16 ET45 on Pontiac Firebird: shock absorber side +12.4 mm, wheel arch side 0 mm, tyre diameter +3.6 % : fit it with the original tyre size of Pontiac Firebird (215/60R16), not that of Cadillac Seville. Comparison for guidance only (estimated width). Check in detail

  • ≈6.5Jx15 ET10 · 205/75R15

    Pontiac Firebird has no 15-inch original wheel in our data: check the approved fitments and caliper clearance.

Before fitting the wheels

An identical hub is not enough: offset, width and diameter change the position of the wheel, and larger calipers can touch a smaller wheel. Original wheels often use bolts or nuts with a specific seat: keep the fixings intended for the wheel, with the thread of Pontiac Firebird (Ecrous - 12x1.50), tightened to the torque shown on its vehicle page. Finally, check that the size is among the approved fitments for your vehicle. This comparison is for guidance only: have the fitting approved by a professional.

And the other way round: wheels from Pontiac Firebird on Cadillac Seville?