North American auto makers will build an estimated 1.373 million vehicles in May, 1.2% below year-ago.

The estimate is about 33,000 units below the 1.406 million planned at the beginning of the month. (See related data: Ward's North American Estimated Production by Manufacturer and Country)

Taking into account a Ward's U.S. sales forecast of 1.5 million light vehicles for the month, that leaves the revised U.S. dealer inventory outlook for May 31 at 3.3 million domestically produced vehicles, 3.6% below year-ago. (See related story: U.S. Sales to Maintain Relative Strength in May)

On average, 85% of North American production comes to the U.S.

Days' supply of domestically produced light vehicles is forecast at 66, compared with 76 the prior month and 68 in May 2004.

May's estimated production shortfall is due entirely to trucks. Cars are set for a slight overbuild.

U.S. inventory of domestically made light trucks is forecast to end the month at 2.30 million units, a smidgeon above year-ago's total and likely on its way to falling below year-ago levels by the end of June. It will be the first time since September 2002 inventory of domestically produced trucks was not higher than the prior year.

By comparison, domestically made cars have been running below year-ago totals since November 2003. In fact, inventory of domestically produced cars will finish May at just under 1 million units, which would mark the first time it has fallen below that level for the month in at least two decades. It also is 11.7% below like-2004.

Only Ford Motor Co. and Honda of America Mfg. Inc. appear to be meeting production plans. Both are estimated for overbuilds in truck output.

In cars, General Motors Corp., largely due to strong output in Canada, is heading for an overbuild, while Chrysler Group, Honda and Toyota Motor Mfg. North America Inc. are tracking close to plan.

Factories in all three countries are estimated to be running below schedule in May, with Mexico the only country headed for a build above year-ago.