SILAO, Mexico—General Motors has paused production for several weeks at its Silao, Mexico, assembly plant, which builds the high-volume Chevrolet Silverado and GMC Sierra pickups. The facility was down for the first half of July and is expected to shut again during the weeks of August 4 and 11. While GM declined to confirm exact dates, it stated that the downtime is part of routine efforts to “optimize production.”

Despite being a standard practice for maintenance or model updates, an extended pause is unusual for plants that build GM’s most profitable models. The Silverado and Sierra are also produced in Indiana, Michigan, and Ontario, but the Silao plant plays a key role in meeting demand.