Opel Astra GTC Bolt Pattern, Center Bore & Wheel Offset (2005–2012)
Opel Astra GTC wheel fitment: 5x115 bolt pattern, 70.3mm center bore; 5x110 bolt pattern, 65.1mm center bore. OE wheel sizes and offsets for every Astra GTC v
- 5x115bolt pattern (PCD), most common
- 70.3 mmcenter bore
- M12x1.5 Nutwheel bolt / nut
- 2 guidesmodel years 2005–2012
Bolt pattern by generation
- 5x115, 70.3 mm center bore — 2012 (1 variants)
- 5x110, 65.1 mm center bore — 2005 (1 variants)
Opel Astra GTC wheel specs by year and trim
| Year | Model / trim | Bolt pattern | Center bore | OE wheel |
|---|---|---|---|---|
| 2012 | Opel Astra GTC | 5x115 | 70.3 mm | 18x7.5J ET41 |
| 2005 | Opel Astra GTC with Panoramic Roof | 5x110 | 65.1 mm | 16x6.5J ET37 |
Factory wheel sizes on the Opel Astra GTC
Across the 2 Opel Astra GTC trims with a documented factory wheel, the OE diameter is 16-18 inch, width 6.5-7.5J and offset ET37-41. A forged wheel that keeps the bolt pattern and hub bore of your generation (see the table above) and stays inside that offset range bolts on without spacers or hub rings. Going one inch up in diameter with a lower-profile tyre keeps the rolling circumference inside the usual 1.5% tolerance; every extra 0.5J of width moves the outer lip about 6 mm outward at the same offset, and each 5 mm less offset moves the whole wheel 5 mm outward.
Forged wheels for the Opel Astra GTC (5x115)
Shop all Opel Astra GTC forged wheels →
Get a quote for Opel Astra GTC wheels
Vehicles With the Same Hub as the Opel Astra GTC (5x115, 70.3 mm Bore)
In our database, 124 other vehicle entries from 8 makes use exactly the same 5x115 bolt pattern and 70.3 mm center bore. Factory wheels from these cars bolt on and center on the hub without rings; offset and width still have to be checked.
5x115 is used by 3.3% of the vehicle entries in our database (209 of 6,396); 65.1% of those also use a 70.3 mm center bore.
Offset and Backspacing: Factory Wheel vs Options
Backspacing ≈ width/2 + ET/25.4 + 0.5 in. "Inward" means closer to the suspension; "outward" means closer to the fender lip.
| Setup | Size | ET | Backspacing | Inward vs OE | Outward vs OE |
|---|---|---|---|---|---|
| Factory (OE) | 18x7.5J | ET41 | 5.86 in (149 mm) | — | — |
| Flush | 19x8.5J | ET35 | 6.13 in (156 mm) | +7 mm | +19 mm |
| Maximum | 20x9J | ET30 | 6.18 in (157 mm) | +8 mm | +30 mm |
Hub-Centric Rings for a 70.3 mm Center Bore
A wheel with a center bore larger than 70.3 mm needs a hub-centric ring. The most common combinations:
| Wheel bore | Ring size |
|---|---|
| 70.5 mm | 70.5 → 70.3 mm |
| 71.6 mm | 71.6 → 70.3 mm |
| 72.6 mm | 72.6 → 70.3 mm |
| 73.1 mm | 73.1 → 70.3 mm |
ANKUSI forged wheels are bored to exactly 70.3 mm for this vehicle, so no ring is needed.
Sources and Last Update
Bolt pattern and center bore were checked against at least two independent fitment references before publication.
This record is part of the open ANKUSI Wheel Fitment Dataset (DOI 10.5281/zenodo.23241521, CC BY 4.0).
Compiled by the ANKUSI Wheels engineering team, an IATF 16949 and ISO 9001 certified forged wheel factory in Guangzhou.
FAQ
What is the bolt pattern on a Opel Astra GTC?
The Opel Astra GTC uses a 5x115 bolt pattern on most variants we cover with a 70.3mm center bore. Other generations use 5x110 / 65.1mm (2005–2005). Always check the exact year and trim before ordering.
What is the Opel Astra GTC center bore?
The hub-centric center bore is 70.3 mm on the most common generation; see the table for variants. Aftermarket wheels should match this bore or use hub-centric rings so the hub, not the bolts, carries the load.
Do all Opel Astra GTC years share the same wheel fitment?
No. The bolt pattern or center bore changed between generations, so wheels are not interchangeable across all years. Use the year-by-year table on this page to pick the right specification.
Which forged wheels fit the Opel Astra GTC?
Any wheel drilled 5x115 with a 70.3mm hub bore in the offset range shown on the model guide. ANKUSI forges wheels to order for this exact specification, in 14–24 inch diameters, so no adapters or hub rings are needed.