Well, it depends if your car still has manufacturer's warranty.

You do not want to use mixed oils if it is still under warranty.

If you don't use your car very often, determining old change schedule solely based on miles is probably not a good idea. I would recommend that you change oil twice a year.

My car also takes 6QT synthetic oil. So, I bought two bottle of 5QT synthetic oil. I use one bottle plus 1/5th of the 2nd one.

Engine oils degenerates gradually. So, there is no apparent cut-off point. Changing oils after an engine run for 100 to 150 hours is a very good rule of thumb. If your engine runs for 150 hours, and suppose your car runs a zero mile, you still need to change oil.

Good luck!

Alex

所有跟帖： 

• 謝謝這個150小時的提醒，這個車怠速運行比較多，看樣子我要換得勤一點 -ttsu- ♂ (96 bytes) () 11/20/2014 postreply 08:44:07

• "Changing oils after an engine run for 100 to 150 hours", hack, -老生長談- ♂ (120 bytes) () 11/20/2014 postreply 10:17:12

• 自己用腦子算一下唄，相當make sense . -coorslight969- ♂ (0 bytes) () 11/20/2014 postreply 10:46:47

• 很多車是15000邁換油 （不信？），你平均100mph？ -老生長談- ♂ (185 bytes) () 11/20/2014 postreply 11:45:11

• No, Sir. It is not a hack but rather an engineering. -jassco- ♂ (683 bytes) () 11/20/2014 postreply 16:56:21