Tire Alignment or Wheel Alignment: Which Is It?

November 5th, 2015

 

At some point, you may have heard people refer to “wheel alignments” and “tire alignments.” Is there any difference in the two? 

The quick answer to that is: “no.” The two terms are interchangeable with each other, like “wheel balancing” and “tire balancing.”

Now that that’s cleared up, here’s a quick rundown of what wheel alignment means and what it entails. 

Your car’s steering and suspension is engineered with the wheels set at very specific angles in relation to each other and to the chassis of the vehicle. Those angles are set for the best possible ride quality, handling and steering response, and that’s how your car leaves the factory. Normal wear and tear will cause the suspension and steering components to very gradually drift away from those alignment settings. 

If a vehicle has a poorly-aligned front end, It will begin to wear tires prematurely, in an uneven wear pattern, and will display problems in drivability, handling and general road manners. Think of it this way:

Every person’s gait is a little bit different. If someone walks with his right foot skewed out to the side slightly, he’ll end up with a right shoe that’s worn unevenly compared to the left shoe. That’s not unlike how tires wear on a car with front end alignment that’s out of spec. The wheel that is out of line from its normal alignment angle constantly tries to steer the vehicle to one side or another; to continue with the shoe analogy, that condition is called “toe-in” or “toe-out.” 

The out-of-spec alignment of that tire will cause excess friction and drag that “scrubs” the tread off of an inside or outside edge, in an uneven pattern. That also means the vehicle uses more energy and effort to get itself down the road in a straight line, resulting in poorer fuel economy. 

What Are Signs That My Vehicle Needs Alignment? 

 

These are all dead giveaways of alignment issues: 

 

• Persistent pull to one side, even on straight, flat, un-crowned pavement, requiring you to hold the steering wheel off-center to stay in a straight line
• Steering that feels clumsy or “heavy” 
• Steering wheel doesn’t center itself quickly after rounding a turn
• Tires squeal even while turning slowly on smooth pavement
• Uneven wear at inside or outside edge of front tires, or tread that has an uneven, “sawtooth” wear pattern all the way across

Four Wheel Alignments

Most new vehicles feature adjustable rear suspensions and require four-wheel alignments. Four-wheel alignments can enhance drivability by making sure that the front tires’ angles are set completely square with the rear wheels. This relationship between front and rear wheels is known as “thrust angle.” Four-wheel alignments are more involved and more expensive, but pay off in terms of drivability and handling. 

Alignment shops use a piece of equipment called an alignment rack, analyzing and measuring all the critical angles of a vehicle’s wheel alignment so the technician can make the minute adjustments needed to bring the vehicle back into spec again. In the case of older vehicles with many miles on them, there may be enough slop and play in worn steering and suspension parts that they may need to be replaced before a proper alignment can be done. 

When we say “minute adjustments,” consider this…if left to its own with no steering input from the driver, a vehicle with a steering angle that is only 1/8” out of spec would drift 28 feet to the right or left of a straight line, over the course of a mile. Have you recently had a hard hit on a curb, pothole or railroad tracks? Are you noticing uneven tire wear or a constant pull to one side or another? Give us a call and set up an appointment with Master Auto Repair and let us help!