dseg

Ah awesome responses. thank you.

My oil cap says SAE 5w-20,
So I plan on ordering Synthetic Amsoil 5w-20

RetiredSFC 97

I've never heard of it voiding a warranty. I'm knew to Mustangs, but I've never heard my Vette buddies ever say an exhaust swap causes issues and they always change theirs out at first opportunity. they're just like the Mustangs, come with a puny exhaust that says sedan more than performance car.

I'll be changing mine out as soon as I recover from the purchase and my direly needed stereo upgrade.

As far as the oil, it's always best to use the oil that is recommended. but the manual also says you may use any oil as long as it meets SAE requirements. But stay with the proper weight.

Royal Purple is the best from what I have heard. I use Mobile 1 in the vette and that's what they recommend so I will be using Motorcraft in my Mustang. (ole Henry)

I did read the manual state you should go by the oil life monitor for normal driving or every six months whichever comes first, which is different than my vette, it says oil life monitor or at least once a year IIRC. So if you don't use the dealer make sure you have it changed where it's recorded should the need ever arise. receipts for oil sometimes gets questioned if you can't back it up.

Take care of your car and it will take care of you.

Art161

Amsoil Signature Series oil is guaranteed for 25,000 miles or one year, whichever comes first, in normal service.

Be sure to get a filter that will handle the specs for the oil.