I have a couple quarts of Maxlife 30wt single grade laying around in my stash. Would it be okay to use these for topoff or as part as a frankenmix with some synth blend or straight dino?
not now, wait till the summer, then add to your heart's content.
Or in the spring, when it gets warm, change the oil with mix 50:50 5w30 and straight 30W. It is very important to know when to run which Frankenmix!!!