LAS VEGAS -- Components and parts are lasting longer, which means fleets will be spending less on replacement parts.

According to survey results from MacKay & Co. presented at the Heavy Duty Aftermarket Dialogue in Las Vegas, the most significant component longevity gains have been in power transmission (parts from the fan to the flywheel). In fact, the group projects demand for power transmission parts will decline (-0.6%) in 2014.

MacKay expects demand for power generation parts (driven axle and powertrain) to grow 7.2% as a result of diesel particulate filters and other aftertreatment regulations.

Other survey findings show cab/chassis demand up 3.2%, electrical up 2.9%, undercarriage demand up 1.4%, and all other parts up 0.2%.

Power generation accounted for 34% of aftermarket parts demand in the United States in 2013, with undercarriage accounting for 21%. Power transmission was 14%, cab and chassis 13%, electrical 8%, and all other parts 10%.

The Canadian market will see a 6% increase overall in aftermarket parts demand. North of the border, power generation will be up 8%, undercarriage 7%, electrical up 4%, cab/chassis up 3%, power transmission up 2%, and all other parts 6%.

Overall, parts pricing is expected to be up 1.5%.