2005 Pontiac Grand Prix GXP tire and wheel sizes, bolt pattern and tire pressure

Bolt pattern 5x115 on every 2005 trim.

Tires for the 2005 Pontiac Grand Prix GXP

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

255/45R18 front + 225/50R18 rear Best-rated standard on 1 trim

Check price on Amazon · 255/45R18 front Check price on Amazon · 225/50R18 rear
265/40R19 front + 235/45R19 rear Best-rated optional on 1 trim

Check price on Amazon · 265/40R19 front Check price on Amazon · 235/45R19 rear

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Trims sold in 2005: 1
Generation: W-body
Other years: 2005
2006
2007
2008
All years (2005–2008)

1 trim sold in 2005

Open a trim for its tire and rim sizes, bolt pattern and tire pressure.

Pontiac Grand Prix GXP W-body

2005–2008 1 trim

Grand Prix GXP 5.3i 303 hp · V8 255/45R18 97V / 225/50R18 95V 2 fitments

Generation: W-body · 2005–2008
Power: 303 hp
Engine: V8, Petrol
Center bore: 70.3 mm
Bolt pattern: 5x115
Thread: M12 x 1.5

Check price on Amazon · 255/45R18 Check price on Amazon · 225/50R18 Wheels 18x8 ET40 · 5x115 · 70.3 mm on Amazon

Tire size	Rim size and bolt pattern	Pressure, psi
Front255/45R18 97V	Rim 18x8 ET40 5x115	38 psi
Rear225/50R18 95V	Rim 18x7 ET55 5x115	35 psi
Front265/40R19 96W	Rim 19x8.5 ET40 5x115	39 psi
Rear235/45R19 94W	Rim 19x7.5 ET55 5x115	36 psi

How to read 97V: 97 is the load index (up to 1,609 lb / 730 kg per tire) and V the speed rating (up to 149 mph / 240 km/h). ET40 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.
Staggered: A wider tire on the rear axle than the front. Front-to-back rotation is not possible.
Thread size: Lug bolt or nut thread — needed when buying aftermarket fasteners.