Hi Guy's/ Gals. I see a lot of posts on the oils debate. This is a little info for the undecided. I have an 09 FLHRC. I change engine oil every 5 to 6k. I put Mobil1 Vtwin in the engine, formula + in the primary and spectro 6 speed in the tranny after the first service. I put 17,000 kilometers on this summer and changed the fluids today in preparation for the winter. Engine/Tranny oil looked great and the mag on the drain plug was absolutely clean. Primary had a small amount on the plug but that was to be expected. These products are worth searching for and are worth every cent. IMO. Thank to Glider for his recommendations.