Jay has given you good advice, just as Mountainbike and I did when you posted this question earlier.
Take a look at: http://community.cartalk.com/posts/list/2165401.page and you will see that all 3 of us are essentially in agreement.
If you have an Owner’s Manual, you need to read it.
If you don’t have an Owner’s Manual, you need to get one–for many reasons.
E-bay is a good source for low-cost manuals.