On the '04 is .060 inches or 1.52 mm. Not sure if it's the same for every year.
Written under the hood on a placard and in your owner's manual.
2000 Buick century gap for spark plug 3.1l
The Spark Plug Gap.060 (In thousandths of an inch)
The spark plug gap for a 2003 Buick LeSabre should be set at .060 inches. The best spark plug for this vehicle would be an Iridium plug.
plug gap is .060
The gap is .060
spark gap 1984 regal 3.8
.060
The spark plug gap for a 1993 Buick Century is: .045 for the 4 cyl 2.2 engine .060 for the V6 3.3 engine
The spark plug gap for a 2000 Buick Regal should be set at .060 inches. New spark plugs may be purchased at an auto parts store and will be preset.
60
.065