OK Mrs. Purvis, I don't use synthetic, altho it is very good. I do change my oil on about a 4-5K milage basis. When you drain the oil, use a rag, and clean the threads of the plug & the oil pan hole. I'd suggest using a new crush washer, and as prior stated just take it up to tight, and then a 1/4 turn past snug. That should be enough. You can torque it if you want, but in 50+ yrs. of changing oil, I have never done this, not even on my old race cars. I would change the filter each time, make sure the "O" ring is seated in the groove properly, so you don't have a leak there. I use IPD filters and get 6 at a time. The filters are made by 'Mann' same as the factory ones, and cost is lower. You can find IPD on the web, or by phone at 800-444-6473. They are a good source of Volvo parts.

Regards, Sam in Cinci. '01 V70 2.4T & '91 940 Twincam