AC Schnitzer AC4 Complete Wheel Set (8.5x20"/9.5x20") - BMW G Series Models

Features of the AC4 Flowforming Wheel:
- Engineered in Germany
- Weight optimised
- Heat treated
- Developed exclusively for BMW vehicles
- Equipped with the exclusive AC Schnitzer logo 
- 2-year warranty
- Production monitored according to ISO standards

What's included (No Tyres):
- 2x AC4 8.5x20" Front Wheels
- 2x Front Spacers & Extended Bolts
- 2x AC4 9.5x20" Rear Wheels
- 2x Rear Spacers & Extended Bolts

What's included (With Tyres):
- 2x AC4 8.5x20" Front Wheels
- 2x Front Tyres (235/35/R20 on G20/21/22/23, 255/35/R20 on G26, 255/30/R20 on G29/A90)
- 2x Front Spacers & Extended Bolts
- 2x AC4 9.5x20" Rear Wheels
- 2x Rear Tyres (265/30/R20 on G20/21/22/23, 265/35/R20 on G26, 275/30/R20 on G29/A90)
- 2x Rear Spacers & Extended Bolts
- 4x TPMS Sensors
Mounted and Balanced

Philosophy/Design
A technically modern design combined with a high quality production process, these attributes characterise the AC Schnitzer AC4 Flowforming wheel generation, which is launched in the sizes 8.5J x 20" and 9.5J x 20", in the colour variants Bi-Colour Silver/Black and Black.

The circumferential undercut reflects the high technical standard of the AC4 Flowforming wheel. This is because this design element can actually only be realised if it is machined out of a solid material, such as is required in the forging process, as it is located behind the spokes. The undercut of the AC4 Flowforming wheels is particularly visible on the Bi-Colour version, as it brings out the high quality aluminium with its silver surface.

Material
Only high quality aluminium alloys with the AlSi7 or AlSi11 specification are used. 
Both types of material are additionally heat treated in the production process, which results in higher strength and simultaneous weight reduction. Material samples during the production process guarantee the constant and high quality of the material.

Production
Due to the production process, the new AC4 Flowforming wheels are lighter than conventionally cast alloy wheels and this is measurable: the 8.5J x 20" weighs just 11 kg and the 9.5J x 20" wheel also weighs only 11.9 kg.

The flowforming process is one of the most advanced manufacturing technologies in wheel industry. In this production process, after the actual aluminium casting, the raw product is further processed by rolling it out. This step serves to compress the metal, which guarantees greater stability and impact resistance of the wheel.

On the other hand, the improved stability also allows the design of the wheels to be more intricate, as the wall thicknesses can be significantly thinner compared to conventionally manufactured wheels.

Bi-Colour Surface
In this process, the wheel is first primed, then completely painted, and finally sealed with an acrylic clear coat. The surfaces that will later have a shiny metallic finish are then machined. Finally, a two-layer clear coat is applied, consisting of a polyester primer and the acrylic clear coat.

Black Surface
In this process, the wheel is first primed, then completely painted. A two-layer clear coat is then applied, consisting of a polyester primer and the acrylic clear coat.

Test Procedures / Safety
After their design, the first sample rims are manufactured under real production conditions. These must undergo a multitude of tests. Among other things, the strength is tested. The "wheel life" is simulated in the bending circumferential test. Every AC Schnitzer wheel must withstand this intact in order to be allowed to be produced and sold at all.

This is followed by vehicle specific tests, including test installations with check of unobstructed movement and driving tests on public roads and on race tracks. Only after these procedures our rims receive their homologation, i.e. the approval to be used in road traffic.

Wheels are safety relevant components. Therefore, they are checked and tested with the greatest care. This starts with the first chemical material tests and ends with hard testing machine endurance runs:

- § 30 StVZO wheel guideline
- ECE R124
- Bending-rotation tests
- 90° impact test
- Unwinding tests