The American Transportation Research Institute calculated (ATRI) that the average cost of operating each road freight vehicle in the United States was $1.69 per mile. Choosing original equipment parts for heavy good vehicles (HGVs) could reduce this figure significantly.

The ATRI figure cited above factored in fuel, insurance, wages, and maintenance to provide a calculation for the total cost of ownership. The same report explains that repair and maintenance costs for road freight vehicles increased by more than 60% in the decade since 2008. This is widely attributed to growing technological sophistication in trucks and the increase of luxury add-ons.

The report also highlights the correlation between how intensively vehicles are driven and the effect this has on hardware. Intensively driven vehicles often have higher repair and maintenance costs due to greater wear and tear; no surprises there, right? However, this does reinforce the importance of choosing parts that can endure a high number of miles.

Buy Cheap, Buy Twice

Ultimately, if you buy cheap, you buy twice.  When steering system parts in trucks, buses, or other large vehicles need replacing, engineers must decide whether to source the original equipment (OE) part from the vehicle manufacturer, or a similar aftermarket alternative. While the latter may have a tempting lower price tag, poorer quality versions do run the risk of breaking down sooner than expected.

Because third-party parts are not an exact match, it is difficult to ensure the same levels of functionality. For instance, the part may not have endured the same rigorous testing as an OE part and therefore cannot guarantee the same level of performance.

Similarly, the raw material used to produce the aftermarket version might be of varying quality or may not be the same grade as OE parts. Steel is a good example of this issue. Steel mills are upping their game with stronger and lighter kinds of steel, and it’s down to the Tier 2 parts manufacturers to source and test the best quality steel from reputable and trusted materials suppliers.

Misleading straplines are part of the problem. Aftermarket parts are often labelled with "matched quality." However, there aren’t any defined regulations on what this claim actually means. "Matched quality" doesn’t mean the part is the same as an OE part, or that it is OE approved.

The part may also look very different to the original, as some aftermarket suppliers create one part for multiple applications. This method results in a very broad spectrum of applications, with no real engineering expertise for the application at hand. An OE part on the other hand, is made for a specific vehicle.

To keep cost per mile low for any HGV, it’s important to keep part replacement intervals as long as possible. Should an aftermarket part break down, this failure could take a vehicle off the road for weeks at a time — adding to overall costs and necessitating the purchase of yet another replacement.  Engineers that choose OE parts won’t be faced with the headache of recurrent replacements or adjustments.

About the Author: Roger Brereton is the head of sales at Pailton Engineering. Pailton supplies steering systems for trucks and other commercial vehicles.