Cool Mechanics: 4-Wheel Alignment for Your German Automobile
Whether you drive a BMW, Porsche, Mercedes Benz, Audi or Volkswagen, your German vehicle’s suspension is designed to provide maximum road grip in a variety of conditions. These performance vehicles are designed with independent suspension, allowing each wheel to react independently of the others.
Basic suspension geometry and design combined with today’s active traction, braking and body control (available on all Mercedes Benz, BMW, Porsche and Audi vehicles) enable a vehicle to maximize the contact patch between the tire and the road surface. The size of the contact patch changes constantly as road conditions and wheel position (turning) changes. (Contact patch is the size of the area where the tire and road are touching). For example, when you turn right or left, the front wheels will lean over and as such reducing the surface area where the tire and road are in contact. In turn, this reduction in the contact patch reduces the gripping force the tire has to hold the vehicle to the road.
There are three basic geometric settings on your Mercedes, BMW, Porsche, Audi or Volkswagen that control how the wheel maintains surface contact and in turn directly effects tire wear.
+ Toe: Toes is the direction the wheels are pointing in relation to the chassis and each other. Your German vehicle is the happiest with a slight toe out condition. This condition means that the front edges of the tires are aligned a little wider (pointing out) than the rear edge of the tire. This creates stability in how your vehicle tracks down the road. If you have too much toe, premature tire wear and loss of power will be noticed (the tire is scraping material off as it goes down the road due to increased friction). Too little toe will cause your vehicle to dart as it hits uneven road surfaces.
+ Camber: Camber is the amount the top of the tire leans in or out as compared to being perpendicular to the road surface. During a turn, the tire/wheel will naturally lean, so the objective is to pre-align camber to compensate and maintain the road contact patch. Most BMW, Porsche, Mercedes Benz, Audi or Volkswagen’s are aligned with a slight negative camber (the top of the tire leans inward). Too much negative camber will cause the inside edges of the tires to wear prematurely. On the other hand, an increased amount of negative camber will increase cornering grip and improving handling in high performance situations.
+ Castor: Castor is the rake or angle the tire/wheel is positioned fore and aft. This alignment is rarely affected unless your BMW, Porsche, Mercedes Benz, Audi or Volkswagen has hit a pot hole, curb or other immobile object. Like a shopping cart with a bad wheel, too little castor will cause a wheel/tire to shake and jump around on uneven surfaces.
One thing that makes your German auto unique, as compared to domestic and other imports, is the fact that all four wheels (front and back) can be adjusted (aligned) and tuned for road and driving conditions. Whether you drive a BMW, Audi, Porsche, Mercedes Benz or Volkswagen, each manufacturer provides a specific alignment specification. Your German automotive experts at German Auto Center recommend you check the alignment at least once per year or if you notice any handling or tire wear conditions.
With proper maintenance, today’s German performance vehicles will serve you for many miles and years to come. Trust our experts in Porsche, Mercedes Benz, Volkswagen, Audi, and BMW service in Austin. If you have any questions, simply come by and see us at German Auto Center and we will be happy to assist you.
