Well, "Magilla" just turned 20,000 miles and I changed the auto trans filter (Napa unit) and flushed the fluid , replacing with Valvoline Mercon V. Reminents in the pan were the normal, fluid visually appeared clean with no odor, just had a personal desire to do all this at about 10,000 miles, but just got buzy. Anyway, while the trans always did shift nicely firm, the fluid change definitely made a very nice difference. Although i have no evidence to support, my gut instinct is that the Valvoline oil has either a higher quality base or greater quantity of anti-shudder additives the the OEM oil by my "feel". Anyway, very easy and very good results.