For emissions control, ring packs, and vehicles that do not meet the mileage requirements of the Basic and Sludge applications, such as: Classic cars that drive only 2,0003,000 miles per year. Vehicles that recently failed a smog or emissions test and need a 30-day remedy. Vehicles that need only to clean up ring packs. Vehicles that need to switch over to full synthetics to take full advantage of extended drain intervals. Vehicles that need to change to synthetic oil prior to cold weather setting in. Known severely sludged engines that want the fastest pathway to a clean engine Contact Auto-Rx customer service for your custom procedure. This is a double dose treatment and strict terms and conditions apply