Sounds good, but what does it say about tyres and rims?
The rim
Every wheel is a technical masterpiece available in various forms, sizes and designs. Get familiar with the rim jargon and read up on our explanations for some of the most important terms:
Offset, abbreviated as ET (A) Marks the distance between the hub-mounting surface and the rim’s true centreline and is measured in millimetres. If the hub-mounting surface is lower than the rim centreline (negative offset) this results in increased wheel width while a positive offset leads to decreased wheel width.
Bolt circle diameter (B) Describes the diameter and the number of mounting holes. Depending on the respective car manufacturer there is a wide range of different designs.
Hubcap (C) The centrebore is the centre of a wheel and is covered by the mounting hub. In addition to technical aspects it serves as a decorative element which often also bears the logo of the rim manufacturer or the car brand.
Hump (D) A hump is a bump put on the bead seat which prevents the tyre from sliding off the rim due to lateral forces. The marking H2, for example, stands for humps in standard design on both bead seats.
What would Europe be without certification marks? Here are the three most important ones:
VTA stands for Vehicle Type Approval which is awarded to series vehicles following an official examination. Fitting a particular component on a vehicle, such as for example special rims, requires an additional officially approved permit that must be presented during traffic controls.
The TÜV (English: Technical Inspection Association) grants the GS symbol, therefore ensuring “tested for safety” quality. Especially when it comes to tuning, every modified part must be inspected and examined.
ECE stands for Economic Commission for Europe and is illustrated by a capital E in a circle. A component bearing this marking guarantees that all required tests and approvals have been carried out.
Every tyre has a code
These letter and number combinations make up the tyre designation.
The following drawing explains the manufacturer’s information displayed on the tyre:
A: Date of tyre manufacture “3516“ (= 35th week; year 2016) B: Direction of tyre rotation C: Nominal tyre width D: Tyre aspect ratio E: Tyre construction code (R=radial tyre) F: Nominal rim diameter (inch) G: Tubeless H: Load index I: Speed index for maximum permissible speed J: Mud and Snow + snowflake symbol (variants: M&S, MS, M.S., M/S)
TPMS – all under control
Since November 2014, TPMS, or to be precise, tyre pressure monitoring systems, are mandatory in every new passenger car. With the right tyre pressure, you save more fuel on your ride and experience less wear on your tyres. Even accidents, such as for example caused by inaccurate pressure, can be avoided by the automatic warning system.
This system is available in two variations: Direct system, measuring the tyre pressure on the rim by using a sensor. At ALCAR, this system is pre-prepared in all rims and recorded in the TÜV certifications. Indirect system, measuring the tyre pressure via a vehicle’s ABS sensors.
And finally, two “hightechs”
Carspecific wheels are rims that have been developed especially for a desired car, therefore requiring no centring rings for fitting. You will find all relevant information in our DEZENT configurator.
SR3 stands for three-layer finish SR3 optimises every rim and guarantees a long, perfectly protected rim life.The SR3 paint has been put to the toughest tests in independent labs, holding its ground against road salt, rockfall, acetic acid and copper chloride – see for yourself: