U.S. aftermarket demand for Class 6-8, trailers, and container chassis in 2018 is expected to total $30.1 billion once final numbers become available, according to John Blodgett, vice president, sales and marketing, of MacKay & Co., speaking at Heavy Duty Aftermarket Dialogue in Las Vegas.

Vehicle population plays a big role in what happens in the aftermarket. Blodgett shared figures from Wards and FTR showing Class 8 retail sales for 2018 were up 31% and are forecast to be up an additional 10% this year to 274,000 units. However, by 2020 that number is expected to drop by 12%. For comparison’s sake, 20 years ago that number was 189,000.

Class 6 and 7 retail sales for 2018 were 136,000. They are expected to be flat this year and then fall 4% in 2020. Trailer sales reached 316,000 units in 2018; predictions are for them to fall by 2% this year and 8% in 2020.

In 2018 there were 825,000 Class 6 vehicles operating in the U.S., 1.33 million Class 7 vehicles, 3.4 million Class 8 vehicles and 4.6 million trailers. MacKay’s forecast calls for the operating population of Class 6 vehicles to grow by 12% by 2023, Class 7 to decline 6%, Class 8 to grow 8%, and the trailer population to grow 7%.

Vehicle utilization is another factor that drives aftermarket demand, and for the forth quarter of 2018, Class 6-8 power unit utilization was at 85.3%, according to MacKay data.

MacKay is predicting a 1.5% price increase for U.S. parts in 2019, on top of a 3% price increase seen in 2018.

For 2018, MacKay’s Aftermarket Index shows demand up 7.4% in the U.S., 2.9% in Canada and 12.4% in Mexico. Looking further into the number, Blodgett says that in the U.S. the OES channel saw 9.7% growth year over year, while the independent channel was up 4.2%.

In the U.S. truck dealers have 49% of the aftermarket business, distributors 18%, and independent repair garages 9%. The balance of aftermarket sales are through other sources including specialists (7%), engine distributors (5%), auto parts distributors (4% and other sources (8%).

Presenting data based on input from more than 700 fleets, Blodgett said the number one concern for fleets in 2019 is the state of general economic activity, followed by the driver shortage, the complexity of new components (this was the number one fleet concern in 2018), and the technician shortage.

Looking to the future, Blodgett forecast U.S. aftermarket demand as follows:

• 2019 $31.1 billion

• 2020 $32.2 billion

• 2021 $33.3 billion

• 2022 $34.9 billion

• 2023 $36.3 billion

Related: Economic Growth Ahead at Trend Level, Says Economist at Aftermarket Event