My Ridgeline just turned 104K miles after almost 17 years of ownership, where my average OCI has been 5,300 miles using quality blends or full synthetics. I don't suspect much if any varnish or sludge in the motor, but I decided to add 12 ounces of MMO for the final 250 miles before my next oil change. Honda states in its owners manuals that it doesn't recommend using any oil additives. Is that a concern, or should I just leave the MMO in for 250-300 miles with no concerns?