There's another way NASCAR stock cars don't resemble the car you probably have in your driveway. Add to the list of such obvious things as the big numbers on the side, the wheels and tires and the headlight decals … and the less visible items, like tube frame chassis and carburetors … one more difference. The fuel. That Sunoco poured into the cars every 35-50 laps or so is not the same as you can buy at your local blue and yellow gas station.
It's leaded.
And that rankles a lot of environmentalists. According to a story in Scripps-Howard newspapers this week, the group Clean Air Watch sent a letter to NASCAR chairman Brian France not too long ago.
The environmental group, CAW, is asking the racing organization to switch to unleaded fuel for its teams' racing engines. They point out that lead is being eliminated from gasoline in most places around the world because it presents a clear threat to public health.
CAW also suggests that the continued use of lead additives in gasoline may be creating an unnecessary risk of serious health effects for millions of spectators and nearby residents."
Levels of lead in the blood of American kids have dropped dramatically since lead was eliminated from commercial gasoline in the 1970's and 80's.
Blood lead levels of less than ten parts per million have been shown to diminish a child's mental capacity for the rest of his or her life. Ten ppm is considered a low blood level. Studies have shown a connection between low lead levels and criminal behavior, hearing loss and difficulty in the body's ability to use vitamin D.
High lead levels can cause convulsions and death.
Congress exempted auto racing and the aviation industry from the unleaded gasoline requirement in 1990. About seven years ago, the USEPA has been trying to get NASCAR, and probably other gasoline powered racing series, to use unleaded voluntarily. Unleaded was tested in some NASCAR races in '98 and '99.
But a NASCAR spokesman said that nothing so far has shown that unleaded will work in racing engines.
Lead in gasoline does a couple of things. For one, it slows down the rate at which gasoline burns. As designers worked to get more power out of the internal combustion engine with higher compression ratios, they found that when gas is ignited at higher pressures, it explodes harder, causing shock stress on the moving engine parts. It's that "pinging" you sometimes hear if you listen closely.
Slowing down the burn rate a little by adding alkyl lead eliminates that wear and tear on the engine while still allowing the higher compression ratios that produce more power.
After the elimination of lead from the gas you and I use, engine builders had to go back to lower compression ratios to eliminate "ping."
The other thing lead in gasoline does is to help lubricate valves.
NASCAR spokesman Ramsey Poston said that his organization will continue to try to switch to unleaded but hasn't found any way to replace the valve lubricating function.
Not to suggest that Mr. Poston is not being entirely frank, but we suspect that the function of lead that they haven't been able to replace with anything else is the reduced burn rate. They like their high compression ratios in NASCAR.
Here's an idea. Use unleaded at Daytona and Talladega, eliminating the need for those nasty restrictor plates. Teams that want their engines to last 500 miles in those races would be forced to use lower compression ratios, thereby reducing power and, as a result, top speeds.
After that, they could go to hybrid engines on superspeedways.