| by torquing them to a higher (40 ft-lbs) than recommended (38 ft-lbs max) while using a lubricant. If they stretched permanently, this would cause a net loss of preload and eventual loosening of the fastener would be the next logical step. The torque specs in the FSM for fasteners are quoted without lube. These torque specs are on the high side to offset the amount of friction between the dry threads and bolt head washer face to ensure the fastener is preloaded properly. If you lubricate a fastener's threads and washer face, the friction will be reduced and the bolt will turn farther with the same amount of torque applied... torque specs for lubricated fasteners are always reduced to offset for this reduced friction. The amount of torque reduction will depend upon the quality of the lubricant (ARP lube > regular grease > oil). This does not mean lubricating fasteners is a bad thing - I highly recommend doing so with every fastener on the car to prevent damage to the threaded holes, just remember to reduce the torque to compensate for the reduced friction.
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