As a result of the VW case, the EPA is requiring additional on-road tests of gasoline and diesel engines using portable emissions measurement systems installed onboard. Lee says the EPA has 23 PEMS devices already in use for heavy-duty truck testing.

“But that’s not nearly enough to test everyone’s vehicles if we are going to keep doing this across the board,” he says. “They will have to buy some more equipment.”

About a month ago, the EPA hosted an informational conference call with automakers about the new testing requirements, but Lee says engineers left with more questions than answers. Details were scarce.

EPA officials would not provide the brand of PEMS testing device they will use, the kind of driving loop to be employed or whether the same driving loop would be applied to all automakers. “I don’t know if it’s under development or if it’s under cloak,” he says. “But at this point, we really don’t know anything about how they will be testing.”

Until now, FCA did not employ PEMS testing. “Why? Because it’s expensive, but that’s not the real reason. It adds hundreds of pounds to the car,” Lee says. “When you test on the road, it’s highly variable because of temperatures and driving conditions. The driver style has no way of being maintained. If you do it in mid-winter or mid-summer, you get different data.”

Members of Congress publicly skewered EPA officials upon learning the International Council on Clean Transportation, working with West Virginia University, discovered the discrepancy in VW diesel emissions, and not the EPA. The accelerated level of testing now under way is intended to show Washington that the agency is on guard, Lee says.

“You’ve got to expect the agency will push, and they will find something somewhere to show that they pushed,” he says.

The lack of a “rigorous methodology” for checking emissions, whether in Europe or at a company such as VW, is an invitation for trouble, Lee says.

“Over time, any system that doesn’t have a re-zeroing somewhere will drift. And I think it shifted in a direction of improving image and improving positioning for sales,” he says. “It didn’t drift in the direction of more stringency. And I’m not just talking about VW. I’m talking about the system.”

tmurphy@wardsauto.com