Up to 30% off on alloy wheels and wheel accessories only until 30 April at 12:00 CET. EXPLORE

Close

Categories

Wheel & tyre sizes: what every driver needs to know

Decoding wheel and tyre sizes like 8.0J x 19" ET 43 or 235/55 R19 105V can seem complex, but understanding them is crucial for safety and performance, especially when selecting Stellantis original parts.

1) Understanding wheel size: 8.0J x 19" ET 43

Here's what these numbers mean:

  1. 8.0: Wheel Width in inches (the internal width where the tyre beads sit). Rim Flange Profile is often indicated with letter -J- (in all Stellantis cars is -J-).
  2. 19": Wheel Diameter in inches. Must match the tyre's rim diameter.
  3. ET 43: Offset in millimeters. This is the distance (indentation) between the wheel's mounting surface and its centerline.
    1. Higher ET (e.g., ET 50) means the wheel sits more inward.
    2. Lower ET (e.g., ET 43) means the wheel pushes more outward. Offset affects clearance with brakes/suspension and fenders.

2) Understanding tyre size: 235/55 R19 105V

Here's the breakdown:

  1. 235: Tyre width in millimeters (nominal section width).
  2. 55: Aspect ratio (sidewall height as a percentage of tyre width). For 235/55, the sidewall height is approximately 55% of 235mm.
  3. 19: Rim diameter in inches. Must match the wheel's diameter (e.g., an R19 tyre fits a 19" wheel). The letter -R- indicates the Radial Construction (standard for modern passenger tyres).
  4. 105: Load index of the tyre is rated to carry up to 925 kg per tyre at its specified conditions.
  5. V: Speed rating of the tyre is allowed for speeds up to 240 km/h.

Both the load index and speed rating come from standardized tables defined by international tyre and automotive standards bodies. If you want to know more about your tyre size, check your tyre brand's website.

3) When to choose smaller vs. larger wheels

Smaller wheels are recommended for:

  • Winter driving: A taller tyre sidewall offers better cushioning, absorbs road imperfections, and provides improved grip on snow and icy conditions.
  • Comfort-focused driving: More sidewall means a softer ride.
  • Cost efficiency: Smaller tyres are generally less expensive to purchase and replace.

Larger wheels are better suited for:

  • Summer/dry conditions: Optimized for performance on warm, dry roads.
  • Sportier handling: A lower-profile tyre offers more responsive steering and cornering precision.
  • Aesthetics: Larger wheels provide a more dynamic, premium look.

4) From theory to practice: what wheels can be installed?

Choosing wheels isn't just about physical fit; it's about what your vehicle is approved to use and what the wheel is homologated for.

A) For production (OEM) wheels

If you want the exact wheels installed at the factory provide us your VIN (chassis number): we use it to check manufacturer documentation and look for the original wheel code that is registered as installed from production. We supply the matching genuine Stellantis wheel with the correct specifications.

Why VIN matters: Wheels are often similar to each other, in their design and colour, avoid confusion and go for the right wheel registered in the documentation.

B) For different sizes

If you're changing wheel or tyre size, you must refer to your CoC (Certificate of Conformity):

  1. Find the list of approved wheel/tyre combinations for your vehicle.
  2. Only consider wheels and tyres that align with these approved combinations. This prevents clearance issues, legal and insurance problems, and ensures compatibility with braking systems.

Note that through the VIN we are usually unable to check the alternative wheel/tyre sizes allowed, that is why is necessary to check in your CoC.

C) Beyond size: weight and homologation are critical

A wheel with the right (CoC-registered) size from a different car model may still be incompatible. Wheels are homologated for specific vehicle applications. For instance, a wheel from a lighter car, even if the same size, may not be approved for a heavier model due to different weight categories. That is why, you should always choose from the available wheels for your specific model and production generation.

D) Engine type can impact wheel specs in new models

Vehicles with multiple powertrain options (combustion, MHEV, PHEV, BEV) often have different approved wheel specifications due to weight and component variations.

Example: New Peugeot 3008 (2024+) / 5008 (2024+)

  • Combustion / MHEV: 7.5J x 19" ET 50
  • PHEV / BEV: 8.0J x 19" ET 43

Even though both are 19-inch, the differing width and offset are crucial. Always confirm the allowed wheel sizes for your specific vehicle configuration.

To sum up, how do we ensure your correct Stellantis wheel choice:

  • Factory-identhical wheels: Provide your VIN, and we'll precisely identify the original wheel code from technical documentation. Gurantee of getting the same exact wheel.
  • Different sizes: Share the allowed combinations from your CoC, and we'll verify which OEM wheels match, considering all vehicle-specific factors.

This ensures a simple, correct, and safe selection, preventing costly errors.