I have a GMC Canyon with 110,000 miles. It has the I5 engine. For the last 10,000 miles or so I hear more engine noise on startup. I have always used M1 10-30 syn and OCI's at around 10,000 mi. Have had the oil sent to Blackstone a few times with good results. I am just wondering if I should start using M1 10-40 high mileage. A mechanic friend says some engines just get a little more noise with age. What are your'e thoughts. Also I do tow a boat if that matters.