I own a Volvo s80 2.9 and I already put in 161,000 miles on it and I don't have any troubles. and it depends on how you take good care of your car. I always use top quality brand, oils (Lubro Moly 5w- 30 synthetic), gasoline (91 and above Shell premium), Do regular maintainance such as oil changes and filters every 5,000 miles. Transmission oil and filter change every 35,000 miles. I regularly have my car wash.