Answers to the most important questions about wheels, vehicles, and fitment.
FitmentFinder is a professional wheel fitment calculator for cars. We help you find the perfect wheels for your vehicle with technical specifications, compatibility checks, and visual preview.
Our calculator automatically checks compatibility between your vehicle and desired wheels. Simply enter your vehicle model and wheel data – we'll show you if the combination fits.
All wheels can be purchased directly from the SIXNINE Wheels shop. Click "Buy Now" on the wheel page to be redirected to the store.
PCD (Pitch Circle Diameter) is the diameter of the circle on which the wheel bolts are arranged. Format: 5x120 means 5 bolts on a 120mm diameter circle. PCD must match your vehicle hub exactly.
Offset (ET) is the distance between the wheel centerline and the mounting surface. Positive ET: Mounting surface is outside center (wheel sits further in). Negative ET: Mounting surface is inside center (wheel sits further out). Incorrect offset can cause tire rubbing or steering issues.
The center bore is the central hole in the wheel that fits over the vehicle hub. It must be at least as large as the vehicle hub. If larger, hub-centric rings are used to precisely center the wheel.
Tire size depends on wheel size. Format: 225/40 R19 (Width/Profile Diameter). Our calculator automatically suggests matching tire sizes based on your wheel choice. Important: Overall diameter should stay close to stock (±3%).
Offset (ET) is measured in millimeters and calculated as the distance between the wheel centerline and mounting surface. A higher ET value means the wheel sits further inward (e.g., ET45), while a lower ET value brings the wheel outward (e.g., ET20). Use our ET calculator to determine the optimal offset for your vehicle.
Wheel width is measured in inches and determines how wide the tire sits on the wheel. 8.5J means 8.5 inches inner width. The matching tire width depends directly on this: An 8.5J wheel typically requires a tire with 225-245mm width. Wider wheels offer more grip but may not fit due to space constraints.
Wheel spacers are needed when: 1. The ET value is too high and the wheel sits too far inward, 2. Brake calipers rub against the wheel, 3. You want to widen the track for a sportier appearance. Important: Spacers must be TÜV-compliant and approved for your vehicle. Our configurator shows you if spacers are recommended for your combination.
Hub rings are used when the wheel center bore is larger than the vehicle hub. They fill the gap between wheel and hub and ensure precise centering. Example: Wheel with 72.6mm bore on BMW with 72.5mm hub → hub ring 72.6→72.5 needed. Without hub rings, vibrations occur and wheel bearings are excessively stressed. Our system automatically calculates the required hub ring diameter.
The number combination on the tire consists of load index and speed index. Example 92Y: 92 = load capacity of 630kg per tire, Y = approved up to 300 km/h. The load index must cover at least half the axle load (including safety margin). The speed index should match or exceed the vehicle specifications. Our calculator automatically checks if the selected tire meets these requirements.
Rolling circumference is calculated from the tire diameter. Formula: (Wheel diameter × 25.4) + (2 × Tire width × Aspect ratio/100). Example 225/40 R19: (19 × 25.4) + (2 × 225 × 0.40) = 482.6 + 180 = 662.6mm diameter. Rolling circumference should deviate maximum ±2.5% from stock to avoid speedometer and ABS errors. Our ET calculator automatically shows you the percentage deviation.
Square Setup: Same wheel size front and rear (e.g., 4x 19x8.5 ET35). Staggered Setup: Wider wheels in rear than front (e.g., front 19x8.5, rear 19x9.5). Staggered improves traction for RWD but prevents tire rotation.
A staggered setup (wider wheels in rear) is recommended for high-power rear-wheel-drive vehicles. The wider rear wheels (e.g., 9.5J instead of 8.5J) provide more contact patch and improve traction during acceleration. Typical applications: BMW M models, Mercedes-AMG, Porsche 911. Disadvantage: Tires cannot be rotated (front/rear swap), leading to uneven wear.
The choice between 18 and 19 inch depends on your priorities: 19 inch: Sportier appearance, better steering response, but harsher ride, more expensive tires. 18 inch: More comfortable suspension, cheaper tires, better tire comfort, often lighter. For performance vehicles (M, AMG, RS), 19-20 inch are common. Our configurator shows you available sizes for your specific model.
Flow-forming (Rotary Forged): Semi-forged wheel where the barrel is stretched under pressure and heat. Advantage: Lighter than cast, cheaper than forged. Forged: Milled from solid aluminum block. Advantage: Maximum stability at minimum weight, ideal for sports cars. Disadvantage: Higher price. Both variants offer significant advantages over standard cast wheels.
BMW models typically use PCD 5x120 (older models) or 5x112 (newer G-series). Use our calculator or browse our BMW vehicle database for specific models and compatible wheels.
Audi typically uses PCD 5x112 (A3, A4, A6, Q5, Q7). Visit our Audi vehicle pages for detailed compatibility information.
Mercedes-Benz uses different bolt patterns depending on model series: Compact models (A-Class, CLA) usually use 5x112, Mid-size (C-Class, E-Class) also 5x112 with larger center bore (66.6mm), Luxury class (S-Class, GLE) partially 5x112 or 5x130 for AMG GT. Center bore is particularly important for Mercedes – always check with our configurator.
Porsche uses different bolt patterns depending on model: 911 (991/992) and Cayman/Boxster (981/982) use 5x130, Macan and Cayenne (new) use 5x112, Taycan uses 5x130. Load capacity is particularly important for Porsche – sports cars reach high axle loads. Our calculator automatically checks if selected wheels meet the required load capacity.
The Audi A4 B9 (2016-2023) offers various stock wheel sizes: Compromise between comfort and looks: 19 inch (e.g., 8.5Jx19 ET40). Sporty-performance: 20 inch (9Jx20 ET33 front, 9.5Jx20 ET40 rear). Winter/comfort: 18 inch (8Jx18 ET40). Bolt pattern: 5x112, Center bore: 66.6mm. Our configurator shows all TÜV-compliant options for your A4 with specific tire recommendations.
The BMW M3 G80 (2020+) has specific requirements: Bolt pattern: 5x112 (not 5x120 like older M models!). Center bore: 66.6mm. Stock: 19 inch front, 20 inch rear (staggered). Performance setups: 20 inch all around or 20/21 staggered. Important: High axle loads (front up to 950kg) require wheels with high load capacity. Our system automatically filters all wheels approved for the M3 G80.