Dec 29, 2008 2:14 PM

Most people know that misaligned axles on tractors can result in irregular wear on the steer and drive tires. But what about the trailers?

Total vehicle alignment refers to the tracking of all axles on a vehicle including the trailer. When a vehicle is out of alignment, the tires are literally dragged down the road which, of course, increases rolling resistance and fuel consumption.

A common misalignment condition found on trailers is called "dog tracking," said Peggy Fisher, president and chief operating officer of TireStamp, a tire data analytics company that collects and analyzes tire pressure, temperature, and mileage data to reduce operational costs for commercial and passenger fleets.

"You can see this when following a rig down the road and the trailer appears to be traveling at an angle to the tractor," she said. "Not only are the tires dragged down the road, but since the trailer is not right behind the tractor, the wind hits its side, which also increases drag and sucks up fuel.

"A vehicle that is out of alignment at each tire position can lose more than 2% in fuel economy," Fisher said.