A series of changes in federal safety and environmental rules governing become effective on Saturday, September 1st.  The three biggest changes are to crash test results and fuel economy ratings, and a requirement that all 2008 vehicles have tire pressure monitors.  The changes are the result of legislation adopted in 2005.

National Highway Traffic Safety Administration regulations will now require government crash test ratings to be listed on the vehicle’s window sticker.  Most models for sale in the United States are crash tested by the government.  When a vehicle is not, the automaker can pay for testing.  All of GM’s 2008 models have ratings.  (GM elected to do so, in the belief that customers will be reluctant to purchase a vehicle which is not tested and rated.)  

According to a spokesman for Ford, 92% of its vehicles are rated.  Chrysler was not able to provide information indicating how many of its products were rated.

For its part, the federal government is hastening the crash testing process, to get ratings to automakers sooner.  Once results are received by the automaker, they must be included on the window sticker within thirty days.
 
The new rules also include changes in the way fuel economy is calculated for government fuel economy numbers.  Under the new rules, adopted by the Environmental Protection Agency, mileage ratings will be lower than in the past, because the new EPA testing is designed to more closely resemble real world driving than was the old testing standard.  On an average, new city mileage ratings are about 12% lower and highway ratings are about 8% lower.  However, ratings on hybrid vehicles go down about 20%.

The third big change is the requirement of tire monitoring systems on all new cars.  Though many cars have included these systems for years, the impetus originally was tied to run-flat tires.  Monitoring systems were included in cars equipped with run-flats because such tires outwardly appear normal even with zero air pressure due to the stiffer sidewalls with which the run-flat tire is built. However, a series of rollover accidents involving Ford Explorers, accidents which generally were traced to underinflated tires, lead to the realization that SUVs, in particular, were potentially unstable with underinflated tires, resulting in the new rule.

The new rule requires only a very simple system, merely warning of a severely underinflated tire within 20 minutes of the condition’s being detected.  However, most automakers are using systems which display the actual pressure in each tire on the instrument panel.

A fourth change in the rules concerns side-air bags.  Manufacturers have agreed to a voluntary program that will have side air bags installed for the 2008 model year in 50% of all new cars weighing under 8500 lbs.  In 2009, federal standards will require side air bags in all new cars.