Today I went to Walmart to pick up some M1 (full syn) for my wife's CX-9 as its due for an oil change. They had no 5 qt bottles of 5W-30 on the shelf, and they wanted almost $9 a qt for the M1 in 1 qt bottles, so I picked up a 5 qt bottle of Valvoline (also full syn) for $21, and a 1 qt bottle for something like $5 or $6. So for less than $30 I got what I usually pay about $35 for when I get the M1. If I like the Valvoline maybe I'll start using it on a regular basis. I only go 5K on my OCIs (because its a turbo), so the Valvoline should be good for that long. Are any you aware of any issues with the Valvoline full synthetic?