Well, to save money on motor oil change, especially when you have complete synthetic oil for your car(s), you need a computer and able to connect to internet. Since you can see this article, of course, you meet the basic criteria.
Step2
Open your web browser (FireFox, IE or else) and link to the provided web addresses below. Note: I personally like Castrol syntec and Mobil 1 oil so I only provide these two.
1. Castrol oil, http://www.castrol.com/castrol/castrolhomepage.do?categoryId=3240 click on "Promotion" to find out more information on Rebate/prizes/games
2. Mobil 1 oil, http://www.mobiloil.com/USA-English/MotorOil/Rewards/Mobil_1_Rewards.aspx
Step3
Castrol and Mobil 1 always have promotions/rebates on their motor oil products. For example, when you buy Mobil 1 oil, you can get reward points as you register to their web site. Then you can use your points to redeem products from Mobil 1. Or you can print out the rebate form, offered occasionally from either Castrol or Mobil1. Send the form along with your oil change receipt to request a check, which sometimes worth $10 bucks. You better check their web site monthly to catch the up-to-date promotions.
Step4
If you want to save more money on oil change, buy the oil from retailer stores like Walmart, Autozone...etc, and change oil by yourself. Or you may bring oil to car maintenance center to have them do it for you. So you don't have to wet your hands and only pay for the labor. This way, you can make sure your lovely car has the best oil you provide.
Step5
For bonus, you may like to surf on those two web addresses provided in step 2. They have online quiz/games for you to win for grand prize to small things. I myself not only save money on oil change but get more free stuffs (free songs, gift cards and T-shirt).
Tips & Warnings
Check out those oil companies' web sites often. They make a lot of revenue and always have good deals for customers. Whenever you surf on internet, just spend few second to check their web sites. You may save some extra money when you have a regular oil change.