Next time you scrounge up $50 or so to fill your gas tank, make this vow: Until the tank is empty, you won't drive above 55 mph on Interstate 93 or 89. You'll keep it slow and steady on smaller roads, too. When you go to fill up again, do the math and check your mileage. Chances are, you've improved your car's efficiency substantially - and saved yourself some money - simply by easing up on the gas.

For all the high-volume debate about the high cost of oil, there has been relative silence about one of the quickest ways to ease the pain at the pump. We're not holding our breath for a new, lower speed limit law at the national level. Here at home, where seatbelts, motorcycle helmets and auto insurance are still optional, politicians are perhaps understandably reluctant (chicken?) to champion any sort of mandatory driving restrictions. Nonetheless, there's no reason for political leaders to do nothing.

In a convincing letter published in the New Hampshire Business Review, Concord lawyer Martin Gross calls for state government to simply set a good example. The government could launch a public awareness campaign about the potential financial savings for drivers. By executive order, Gov. John Lynch could set a 55 mph speed limit for all state vehicles and challenge municipal governments and private companies to do the same. Not a bad start, and not much to lose.

In the two decades when the speed limit was 55 mph across the country, government used to appeal to our sense of safety to get us to slow down. These days, a pitch aimed right at drivers' wallets might be all the more successful.