On two of our vehicles, I use good syns that I pick up at the best prices (sales/rebates combo). Most recent OCI was Valvoline FSwML in one and older PUP in the other. However, I've chosen to pay full Walmart price (minus the rebate) for M1EP for this month's change...because I have to change oil outdoors...and both vehicles see very high mileage...both will definitely exceed 10k by early to mid-March. I enjoy changing the oil, but not outdoors in the middle of winter. Anyone else choose a different formula for this reason?