IFTA member, no diesel rate
Oregon taxes weight and distance instead
Oregon is a full IFTA member and you still report your miles here, but it publishes no per-gallon diesel rate in the matrix, so the cell is genuinely empty rather than missing. Heavy vehicles are taxed on a weight-mile basis: what you owe is a function of how far you ran and how heavy you were, not how much fuel you burned.
The practical consequences are worth knowing before you take a load here. The tax is reported separately from your IFTA return, on a separate Oregon weight-mile tax report. Because it is charged by weight, running heavy costs you more per mile in a way it does not in a per-gallon state. And because it is not collected at the pump, no amount of fuel buying strategy touches it.
That also means the cents-per-mile figure shown for other states has no equivalent here. Rather than invent one from a rate that does not exist, this page says so. Check the current weight-mile table with the Oregon Department of Transportation before you price a load.