To the Editor:
Your July 11 article "Diesel doublespeak: Technology hits a wall" discusses selective catalytic reduction, or SCR, as a solution to the diesel emissions problem.
While that technology cleans up diesel emissions to future standards without harming fuel economy, its disadvantage is that drivers must keep the urea tank filled to keep the system working.
The EPA is concerned that drivers may neglect to do so and that their vehicles will then fall out of compliance.
Here's my solution to the problem: Require anyone selling diesel fuel to offer a corresponding amount of urea at no additional cost to anyone refueling a vehicle equipped with SCR. The cost, of course, would be rolled into the price of the fuel.
The price impact would be minimal at first since rather few vehicles would be using SCR. The impact would rise over time, but the better fuel economy offered by SCR relative to other emissions technologies would offset that.
Yes, drivers of older (pre-SCR) vehicles would be subsidizing urea for drivers of newer vehicles, but that can be regarded as a tax on polluters. Note that the SCR technology applies to heavy trucks as well as to diesel passenger vehicles.
Senior Industry Analyst
Frost & Sullivan
Palo Alto, Calif.
The writer specializes in automotive and transportation issues at Frost & Sullivan, a consulting company.