I want to thicken up the mc 20 wt to about 9.0 vis. The honda seems to like its 20 weight best at that vis. So...What do you all think of mixing one quart of mc 5w30 with 2.75 qts of mc 5w20. Do you all think this mixture will result in overall less quality oil than if using all 5w20. I would like your opinions on this. Thanks in advance r. Not interested in going synthetic or going straight 5w30 at this time.