I'm a believer in RLI. I'm going to do a M1 vs. RLI UOA. I've been planning this test for several months and have been super anxious to get it done. I drive 1,500-2,000 miles per month, so it shouldn't take TOO long to do this.
I have a 2007 Ford Fusion SEL V6 AWD with 18,XXX miles, currently. I'm planning the test to begin this spring and will begin with M1 5w-20 for 5k miles, then will follow up with a fill of conv. Pennz 5w20 for 50 miles, then will fill with RLI 5w-20 for 5k miles. I know, 5k miles isn't that much for syn oils, but I don't want to wait forever to get this done. 5k miles on each oil will be enough to tell which is doing better. Each fill will be using a new Motorcraft FL820S filter. 90% of the mileage will be highway.
I'm scheduling the test to begin sometime around April, so that the M1 will see some cool spring mornings and then some hot summer days, and the RLI will see some hot summer days and then some cool fall mornings. I want the temperature variables to be as close as possible, and since the test will take roughly 6 months to complete, March/April seems like the best starting point. The only argument to this schedule is that the M1 add pack will be fresh during the cold morning start ups, and the RLI will have 3k miles of shearing force on it before the cold mornings begin. Will that affect the wear numbers much? Probably not. I expect the "cold" mornings to be no less than 50 degrees, hardly severe service conditions.
So, if you're interested in seeing the results, look for a post from me next October.
