the problem with the synthetics and +4 is they are all desighned with lots of friction modifiers, those modifiers make the clutches slip when they engage. Slipping clutches makes for softer shifts so the manufactures are useing it to make softer shifts because softer shifts sell cars. On the other hand slipping clutches also mean burning clutches especially at elevated power levals. Type-F has the highest friction and helps the clutches grab faster and slip less. It is somewhat of a trade off because the pistons, gears, bearings and valves will see less wear from higher friction. In my experiance the best trade off is to make the clutches last longer and increase lube to mechanical stuff through minor mods in the fluid flow circuits.