When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Either he has extremely low mileage for a 17 year old car and high mileage oil is not necessary, or was a typo and has 120000 miles which is still low for the age of the car! If the car is leaking oil and you have replaced the gaskets go with a heavier oil to prevent leaks! If not 10w40 I believe was common for your vintage