Common wisdom among many people in the used truck business is that pre-DPF trucks will bring more money than DPF-equipped trucks, specs and mileage being equal. This means that the last of the pre-DPF trucks (2007 model year) should be worth more than the first of the DPF-equipped trucks (2008 model year). In other words, DPF overrides model year.

We tested this theory and, to be blunt, found it false. The graph below shows retail selling prices for MY2007 and MY2008 sleeper tractors broken down by mileage range, for trucks sold in the first 3 months of 2013. Data has been “cleaned” as much as possible to adjust for spec and model, so the impact of those factors should be minimal.
As you can see, 2008’s brought notably more money for every mileage band above 300K.The average premium for a MY2008 sleeper tractor was $5362.
One potential factor behind the difference in pricing is the notably higher volume of 2007’s sold. We show 596 MY2007 sleeper tractors reported sold during this period, as compared to 327 MY2008’s. Higher supply should logically suggest lower pricing, although this factor would be seemingly irrelevant among those who would value a 2007 over a 2008. On the other hand, this volume difference could also point to better demand for 2007’s. However, with trucks under 600K bringing strong money regardless of model year, we find this explanation less convincing.
Any time data contradicts common wisdom we need to investigate deeper, which we will do. At this point, however, it looks like the presence of a DPF is not the marketplace handicap some would make it out to be.