The average of allsubgroups becomes the centerline for the lower plotting area. Average of Ranges Example Step 7 - Calculate the upper control limit (UCL) and lower control limit (LCL)for the averages of the subgroups. At this point, your chart will look like aRun Chart. Now, however, the uniqueness of the Control Chart becomes evidentas you calculate the control limits.
Ford Motor Company recommends that the Crown Vic limit its towing to a trailer with a gross vehicle weight of 1500 lbs or less with a tongue weight not to exceed 150 lbs. See HERE.
The numbers shown represent ratings for conventional towing. If you plan to tow with a fifth-wheel or gooseneck setup, in many cases, the tow ratings will be much higher. The rankings will be different, as well. When it comes to fifth-wheel towing, the Ram 3500 is king of the pack, capable of towing up to 30,000 pounds.