I've been waiting for the right time to use my hole card when it comes to the calls for raising the Corporate Average Fuel Economy in lieu of allowing oil exploration in the Arctic National Wildlife Refuge. The New York Times editorial page on Wednesday affords me just the opportunity.

There are several things the Democrats and their moderate Republican allies can do to produce a respectable bill. First, they must defeat any amendment aimed at opening the Arctic refuge to drilling. Such an amendment is almost certain to be offered by Frank Murkowski of Alaska, but the facts are not on his side. Every available calculation � including those that accept Mr. Murkowski's inflated estimates of the amount of oil underneath the refuge � show that much more oil can be saved by fuel efficiency than by drilling.

The statement that "more oil can be saved by fuel efficiency than by drilling" is meaningless. If you can increase fuel efficiency enough, you wouldn't even have to import any oil. But they don't suggest that solution. Why? Because it is technologically impossible to increase fuel efficiency by that much. If automakers could make an SUV that got 75 mpg, they would make it. It would sell like double-chocolate-mocha-fudge brownies. Ultimately we are constrained by our technology. The oft-quoted number is an increase in the CAFE standards of a mere 3 mpg. Is it possible? One of my letter-writers says no.

I spent 6 years working at one of the big three in an engine group. I left a few years ago, unhappy, so I'm no great friend of the industry. The fact is, we engineers would cheer when we got an improvement of 1/4 mpg increase. It's not special interest groups, it's a combination of physics, customers who demand air conditioning and power everything (weight and power drains), and emissions regulations (require catalysts and other control devices) that keeps the 3 mpg increase from occurring 'easily.' Doesn't he think that GM or Ford would love to advertise that their cars get 3 mpg better mileage than their competitors? An increase of that magnitude would take years and billions.

It's easy to say. But it's not easy to do.