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2021 Alfa Romeo Giulia GTA / GTAm Wheels & Rims: Bolt Pattern, Offset & Sizes
Fitting Alfa Romeo Giulia GTA / GTAm wheels? This page gives the 2021 Alfa Romeo Giulia GTA / GTAm bolt pattern (5x110), centre bore, factory rim size and the offset range for aftermarket and forged Alfa Romeo Giulia GTA / GTAm rims: the same spec sheet ANKUSI uses when machining forged wheels for this car.
Quick answer: The 2021 Alfa Romeo Giulia GTA / GTAm uses a 5x110 bolt pattern with a 65.1 mm centre bore and M12x1.5 lug nuts. Factory wheels: F: 20x9.0J R: 20x10.0J. For aftermarket wheels, 20x9.5J ET25 front / 20x10.5J ET30 rear sits flush and 20x10.0J ET20 front / 20x11.0J ET25 rear is the most aggressive fit.
Forged wheels for the 2021 Alfa Romeo Giulia GTA / GTAm — drilled 5x110 with a 65.1 mm centre bore, built to the offset you choose. From $220 per wheel, made to order in 20–25 days.
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Alfa Romeo Giulia GTA / GTAm (2021): 5x110 bolt pattern, 65.1mm center bore. Factory wheels: F: 20x9.0J R: 20x10.0J. Reference fitment ranges.
Bolt Pattern5x110
Wheel Bolt/NutM12x1.5 Nut
Center Bore65.1mm
Wheel Load Rating700–850 kg/wheel (Performance / Sports Car segment reference)
Year2021
CategoryTrack Sedan
✓ Data check: the bolt pattern and center bore on this page match an independent fitment reference. Last reviewed September 18, 2026. How we verify
Wheel Size & Offset at a Glance
| Configuration | Wheel Size & Offset |
|---|---|
| Factory (OE) | F: 20x9.0J R: 20x10.0J |
| Flush Fitment | F 20x9.5J ET25 / R 20x10.5J ET30 |
| Maximum Aggressive | F 20x10.0J ET20 / R 20x11.0J ET25 |
Forged Wheel Designs for the Alfa Romeo Giulia GTA / GTAm
Every design below is forged to order, so it can be machined to the Alfa Romeo Giulia GTA / GTAm's 5x110 bolt pattern and 65.1 mm center bore, with the width and offset calculated for your setup.
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How to Read Wheel Offset & Measurements
Use these two references before ordering: the left diagram shows where each spec (PCD, center bore, offset, width and diameter) is measured on the wheel; the right diagram shows how positive, zero and negative offset shift the wheel face relative to the hub centerline.
ANKUSI Engineering Expert Advice
The Alfa Romeo Giulia GTA / GTAm's factory wheel spec reflects a deliberate balance between comfort, steering feel and durability that the engineering team tuned for. Forging lets ANKUSI match that same strength target while trimming rotational mass — the part of a wheel upgrade that actually changes how the car drives, not just how it looks.
The Alfa Romeo Giulia GTA / GTAm runs a 5x110 bolt pattern, 65.1mm center bore, and a F: 20x9.0J wheel from the factory. Our Flush Fitment reference is F 20x9.5J ET25 / R 20x10.5J ET30, which tucks the tire under the fender lip on a stock-height Alfa Romeo Giulia GTA / GTAm. Our Maximum Aggressive reference is F 20x10.0J ET20 / R 20x11.0J ET25 — beyond that offset, expect rubbing against the inner fender liner under compression without further trimming.
Alfa Romeo Giulia GTA / GTAm OE Wheel Specs
The 2021 Alfa Romeo Giulia GTA / GTAm (Track Sedan) uses a 5x110 bolt pattern with a 65.1mm center bore. Factory wheels are F: 20x9.0J R: 20x10.0J.
Why the factory spec works for most owners:
- Balances ride comfort with everyday drivability
- A commonly used size for this vehicle class, supporting parts and tire availability
- Maintains clearance for the factory suspension and brake components
- Provides stable, predictable handling across normal driving conditions
ANKUSI builds these wheels — we are the forging factory, not a reseller. For the Alfa Romeo Giulia GTA / GTAm (2021) we drill the 5x110 pattern and cut the centre bore to 65.1mm on our own CNC line, so the wheel hub-centres on the car with no spacer rings, in whatever diameter, width and offset you specify.
Converting these ET figures to backspacing? Use the wheel offset and backspacing calculator.
The figures on this page are part of our open wheel fitment dataset — 10,093 vehicles, free to download, CC BY 4.0.
Offset & Backspacing Reference
Backspacing is calculated as wheel width (in) ÷ 2 + offset (mm) ÷ 25.4 + 0.5 (flange allowance):
- OE: F 20x9.0J ET34 → ~6.34″ F backspacing, R 20x10.0J ET38 → ~7″ R backspacing
- Flush: F 20x9.5J ET25 → ~6.23″ F backspacing, R 20x10.5J ET30 → ~6.93″ R backspacing
- Max: F 20x10.0J ET20 → ~6.29″ F backspacing, R 20x11.0J ET25 → ~6.98″ R backspacing
Want to check a different width or offset before you order? Use our Offset & Backspacing Calculator to solve the numbers yourself, or looking for your exact Alfa Romeo spec, or want a wheel built to a custom offset for your Alfa Romeo Giulia GTA / GTAm? Contact ANKUSI with your bolt pattern and offset target and we will confirm the correct forged wheel spec for your build.
Vehicles With the Same Hub as the Alfa Romeo Giulia GTA / GTAm (5x110, 65.1 mm Bore)
In our database, 139 other vehicle entries from 19 makes use exactly the same 5x110 bolt pattern and 65.1 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.
5x110 is used by 2.2% of the vehicle pages in our English fitment guide (145 of 6,503); 96.6% of those also use a 65.1 mm center bore.
Hub-Centric Rings for a 65.1 mm Center Bore
A wheel with a center bore larger than 65.1 mm needs a hub-centric ring. The most common combinations:
| Wheel bore | Ring size |
|---|---|
| 66.1 mm | 66.1 → 65.1 mm |
| 66.6 mm | 66.6 → 65.1 mm |
| 67.1 mm | 67.1 → 65.1 mm |
| 70.1 mm | 70.1 → 65.1 mm |
| 73.1 mm | 73.1 → 65.1 mm |
ANKUSI forged wheels are bored to exactly 65.1 mm for this vehicle, so no ring is needed.
Frequently Asked Questions
What bolt pattern (PCD) does the Alfa Romeo Giulia GTA / GTAm use?
The 2021 Alfa Romeo Giulia GTA / GTAm uses a 5x110 bolt pattern.
How many lug bolts does the Alfa Romeo Giulia GTA / GTAm use?
The Alfa Romeo Giulia GTA / GTAm uses a 5-lug bolt pattern (5x110), so you need a 5-lug forged wheel to bolt straight on.
What is the center bore size on the Alfa Romeo Giulia GTA / GTAm?
The Alfa Romeo Giulia GTA / GTAm's center bore is 65.1mm. If an aftermarket wheel has a larger center bore than this, hub-centric rings are recommended so the wheel centers on the hub itself rather than relying on the lug bolts alone.
What size are the factory (stock) wheels on the Alfa Romeo Giulia GTA / GTAm?
Factory wheels on the Alfa Romeo Giulia GTA / GTAm are F: 20x9.0J R: 20x10.0J.
What is the biggest wheel size I can fit on my Alfa Romeo Giulia GTA / GTAm without rubbing?
The most aggressive fitment we recommend without fender work is F 20x10.0J ET20 / R 20x11.0J ET25. Going beyond this typically causes rubbing under compression unless you roll the fenders or add camber correction.
What does a flush wheel fitment look like on the Alfa Romeo Giulia GTA / GTAm?
For a flush look with minimal to no rubbing, we recommend F 20x9.5J ET25 / R 20x10.5J ET30 as a starting point on a stock or mildly lowered Alfa Romeo Giulia GTA / GTAm.
Do I need wheel spacers for my Alfa Romeo Giulia GTA / GTAm?
No. ANKUSI forges each wheel to your exact target offset, including the flush or max specs above, so you get the correct fitment without stacking spacers. Spacers are typically only used to push out an existing OE-offset wheel without replacing it, which isn't necessary when you're ordering a custom-offset forged wheel.
How do I calculate wheel backspacing for my Alfa Romeo Giulia GTA / GTAm?
Backspacing (in inches) = wheel width (in) ÷ 2 + offset (mm) ÷ 25.4 + 0.5 (flange allowance). For example, the flush spec above works out to roughly 6.23" backspacing up front and 6.93" in the rear.
What's the difference between wheel offset and backspacing?
Offset is the distance in millimeters from the wheel's true centerline to its mounting face (positive offset pulls the wheel in, negative pushes it out). Backspacing is the distance in inches from the mounting face to the back edge of the wheel barrel. They describe the same fitment from two different reference points, which is why ANKUSI lists both above — some shops and tuning guides quote offset, others quote backspacing.
Can I run staggered wheels (different sizes front and rear) on my Alfa Romeo Giulia GTA / GTAm?
Yes — the Alfa Romeo Giulia GTA / GTAm's factory and our recommended flush/max fitments already use staggered sizing (different width front and rear), and ANKUSI can forge matching staggered sets to your target offsets.
Sources and Last Update
Data checked against: avtoreference.com.
This record is part of the open ANKUSI Wheel Fitment Dataset (DOI 10.5281/zenodo.23241521, CC BY 4.0).
Other cars on the same factory size: 20x9 wheels · 20 inch wheels.
Compiled by the ANKUSI Wheels engineering team, an IATF 16949 and ISO 9001 certified forged wheel factory in Guangzhou.