General Motors Corp. steps out of the pan and into the fryer with the announcement it will close the Mesa, AZ, desert proving ground and move to Mezcala, Mexico. Mesa, GM says, simply isn't hot enough.

“We need average day-time weather temperatures that are in the 90s and Arizona isn't that hot from October to April,” says Ian McEwan, GM executive director of proving grounds and test operations.

The temperatures in Mesa dip into the 60s during winter. Mezcala, on the other hand, meets the required 90-degree average daily temperature needed to perform year-round testing. The yearlong high temperatures are critical to GM's plan to reduce vehicle launch time to 24 to 18 months, a plan that could not be accomplished if testing was only possible from May to September.

Hot-temperature testing of heating, cooling and air conditioning systems only accounts for 10% to 15% of all testing at Mesa. GM has been in Mesa for 47 years.

Even so, GM plans to invest $60 million to build a 5-mile test track and facilities on 3,500 acres in the remote valley 90 minutes north of Acapulco. The site is scheduled to open in 2002 and employ 100 workers for engineering and skilled technician positions. Currently, 400 GM workers and 600 contract workers are employed at the Mesa site. Those not directly involved in hot-weather testing will be relocated to GM's Milford Proving Ground or computer labs in Pontiac, MI.; others will be offered positions in Mexico, severance packages or early retirement.

Since 1953, GM has used the Mesa proving grounds as its hot weather testing sight for air-conditioners, engine cooling and performance, interior and exterior build qualities and other components.