Ive been doing my own oil changes on all my vehicles for the past 20+ years and use nothing but Amsoil products including their extended life (25K miles) filters, gear, steering, and brake fluids. for the past ~15 years I've also been sending my oil samples to
Blackstone Laboratories for periodic analysis. I have a 2006 Silverado 2500HD daily driver that I tow a 13K+ trailer approx. 4K miles a year that they continue to report, in surprise, how little engine wear I'm experiencing even after 180K+ miles even though I typically do changes between ~12,500 miles and always have even though the manual says 7,500 thanks to the science.
The purpose of the tests initially on a vehicle for me is to confirm how many miles, based on my style of driving and conditions, I can go before I need a change. After the initial, I send in for analysis every other to confirm the engine is wearing at a healthy rate and to determine if I need to modify my intervals.
I've typically installed a Fumoto valve to make taking samples quick/painless but because the underside of the 392 makes the valve, even with the steel pan, low hanging fruit I will NOT install one until I get belly skids/protection. This of course isnt a huge problem/show stopper though because I can still use my Holt extraction system where I can pull an oil sample from the dipstick tube... just requires more cleanup.
For me personally, I like using science/analysis to tell me how well my oil and engine are doing and react accordingly. I hope this info/approach helps many of you to reduce the stress, fear, or questions one has about how healthy their oil and or engine are... Check out BL cuz they're worth every penny! And NO, Im NOT affiliated with them in any way shape or form just a long time loyal customer.