Nothing wrong with using Redline for your next fill. The stuff was a miracle performer for racing cars, street cars just take too long to wear out for me to make back to back comparisons.To give you an idea of how good it could work, we had Triumph motorcycle drag engines that had to be rebuilt, valves, valve guides, pistons, bearings, and cylinders, after every race weekend. After switching to Redline, and making no other changes, we went six events on ALL those components. I had great luck in other applications, VW's, Porsches, BMW's, Lotus,Fiats,and Chevy's. None were as dramatic as the Triumph but Redline was CLEARLY better than "normal" oil.In fact, I never could understand how Redline oil improved valve life so dramatically in many applications. The oil going down the valve guide must be very important. I never used any other synthetics so I don't know how they perform.