Tractor Tire Pressure Inflation

Fleets lose millions of dollars annually manually managing tire inflation, leading to blowouts, reduced fuel economy and disruptive downtime. The value of automatic tire inflation has been proven on trailers over the past decades, but tire inflation systems are not just for trailers.  Tractor drive tires can enjoy the same benefits with a slightly different approach to avoid pressurizing, tapping, and drilling powered axles, although that strategy is now starting for tractors too.

Introduction & Rationale

Leaky valve stems, temperature changes, natural leakage, uncalibrated air pressure gauges and other factors can all allow tires to become under inflated. Although trailer tire inflation systems have become common, the benefit to tractor inflation systems is that most tractors accumulate more miles per year which provides a faster payback.

Available Systems

There are 2 types of ATIS (Automatic Tire Inflations Systems) for tractors offered in 3 different fashions.  ATIS Type 1 systems are traditional compressor-based systems that provide air pressure from the tractor to the tire.  One version of this type uses internal pressurized axles like a trailer system while the other uses external air line routing under the fifth wheel around the tire valve stem.  ATIS Type 2 systems are self-contained systems compressing direct atmospheric air and mount on the end of the axle, generate their own air pressure at each wheel end position and connect to the valve stem for either duals or wide based singles.

 

Benefits

Tires operating at their recommended pressure feature an optimized tire patch on the road which maximizes traction, reduces rolling resistance and improves fuel economy.  By decreasing tire rolling resistance, properly inflated tires can increase fleet MPG by at least 1 percent for every 10 percent under inflated.

Properly inflated tires with the designed contact to the road help prevent premature and abnormal wear, and allow tires to last longer.   Fleets may realize up to 15% longer tire life as a result of keeping tires properly inflated, which results in more miles driven on each tire, less time spent replacing tires and substantial tire cost savings.

Improperly inflated tires can fail and cause damage to the truck or other vehicles traveling near it.  Keeping a tire optimally inflated reduces heating and flexing of a tire’s sidewall, the primary reason for a blowout. Blowouts lead to costly road service calls and potential fines for late delivery.

Tire failures on the road create downtime and put drivers and repair personnel in a challenging spot making repairs on the road.

Challenges

If drivers are overly reliant on a tire pressure system and start up the truck before inspection it is possible for tractor air fed tire inflation systems to pump up the tire before the driver inspects it, thereby masking the issue. Pre-trip inspections should not be replaced by technology.

Systems that use tractor air with externally routed lines to inflate the tires much have air plumbing that reaches over the outside of the tire to the wheel end.

Not all systems have an easy to see warning light to notify the driver of issue(s).

Self-contained systems and axle air fed systems will accommodate the installation of aero wheel covers. External systems that feed the air around the side of the tire have a cover in development, but nothing on the market as of February 2018.

Self-contained solutions compress air as the tire is in motion.  Until the vehicle has traveled for while the tire(s) may not be operating on full pressure.

Not all systems are easy to implement on the front steer axle.

Manufacturers