Automakers are no longer in denial that they will have to improve the average fuel economy of their fleets. But they hope they can keep the decisions within the more comfortable confines of NHTSA instead of becoming a political volleyball for Congress.

The head of the auto lobby, Dave McCurdy, told Reuters that NHTSA is the "one agency that has been authorized by Congress to develop those standards" because of the data it accumulates and analyzes.

NHTSA already boosted CAFE for light trucks to 24.1 mpg by 2011 using a weight-based formula. Passenger cars have a 27.5 mpg requirement. That's a plan automakers would like to keep going while Congress is likely to throw around high numbers in an across-the-board increase.

I'm not sure a weight-based formula will give automakers any incentive to reduce the weight of their vehicles. Today's cars and trucks have simply gotten too fat and lazy. Engineers are pressed to make SUVs ride like cars and pickup trucks ride like SUVs. One of the easiest ways is to stiffen up the chassis, which usually means more weight. Comfort items, sound-deadening materials....the list goes on and it all adds up to weight. When vehicles are heavier, engines have to get bigger and more powerful. Whatever fuel economy measures powertrain engineers contribute, the chassis engineers negate with more weight. That's one of the main reasons fuel economy has been stagnant for the past decade.

One report I found said that when CAFE standards were first implemented, the average weight of a vehicle fell by 800 pounds within five years. Lately, with every new generation of particular vehicle model it seems to get heavier. The average weight of cars might be the same or even lower than 30 years ago, but we didn't have large numbers of subcompact cars. My point is that whenever automakers bring out a next-generation version of an existing model or give one a mid-cycle makeover, the vehicle platform usually gets heavier.

I understand the need for certain trucks to be heavy and robust enough for towing and load-carrying purposes. Any fuel-economy formula has to acknowledge that pickup trucks must be addressed separately. But I want to see incentives for automakers to get more of their vehicles on a diet.

[Source: Reuters via CNNMondy.com]