Changed my rear diff fluid this morning. Last time was around 30k miles ago and in 2020.
Fluid was about halfway between new and dark. Only a very small amount of deposits on the magnet and no signs of other visible metals.
Instead of using a pump I just used some clear vinyl tubing I...
'15 AWD w/308k miles
https://www.carfax.com/vehicle/JM3KE4CY4F0523587
'14 AWD w/237k miles
https://westernmass.craigslist.org/cto/d/easthampton-2014-mazda-cx-awd-grand/7843194645.html
'15 AWD w/242k miles
https://newhaven.craigslist.org/cto/d/shelton-2015-mazda-cx5-owner/7842415376.html
I feel pretty confident using the Valvoline R&P with the reports and backgrounds of those testing.. these low-tension piston rings in-use ~2010 or so has made this viable option to help clean up the ring deposit issues
IMO: I don't think there are really any definitive answers to be found now..... I'm gonna keep my game of maintenance up and drive the wheels off current vehicles. No interest in purchasing anything new right now. I had been interested in a RX 450 PHEV but may end up buying a Lyriq instead...