回複：Firestone 換機油

My oil change strategy:

If your car is new and under warranty, go to dealer.  They may charge more but sometimes have ccoupon.  Dealers usually are trustworthy;

If your car is old, do it yourself or find a good mechanic referred by local people who stayed with their mechanic for generations (means mechanic's grandson is doing the oil change for grandson of his grandfather's customer);

Pay more for the service from a more reliable shop.  I used to go to a Goodyear and it's pretty good but I am not sure if all Goodyear shops are the same.  If you look for cheap oil change, be careful!  You need more than at least $15 for oil and filter, etc. even DIY. 

I believe there is a treaty that prevents customer from watching mechanic doing their job so you just can not watch when they are working.