I've been running 10W-30 (factory spec) Mobil 1 in my car ('96 4 cyl. Accord) since new and now have ~210K miles. Unfortunately, by government decree most if not all oil manufacturers have significantly reduced the amount of phosphorus and zinc (both are anti-wear additives) in many of their formulas, the 10W-30 Mobil 1 included.

However, the 10W-40 (and higher viscosities) Mobil 1 supposedly retain the original P and Zn levels. I'll probably give the Honda tech line a call on this, but I was just wondering what the board members think about switching to 10W-40 in my car, at this point.