2013 Base 3.7 with 6 speed. Sync, 3.35 gear ratio.
So, I have been going by the computer. First oil change was about 10,000. Next one is due according to the computer about 20,000. 3/4 highway driving, car is almost one year old. I decided to by a case of Royal Purple and 3 Motorcraft filters since I am trusting the computer. If I only changing the oil every 10,000, I am still saving money buying RP. How do you guys feel about the 10,000 mile spacing?

Second, my wife owns a Hyundau Sonota. I used to laugh when I would walk outside after a humid night or a rain and see rust on her rotors. Now, I haven't actually looked at mine, but I can tell they have surface rust based on the sounds it makes in the morning. I haven't dealt with this issue before on an american vehicle. I don't have the Brembos, just base. Anyone else experiencing this issue also?

 

Unfortunately most rotors are made of cast iron and the bi-product of unprotected cast iron and oxygen is rust. Don't worry though ALL rotors rust…especially when exposed to air or water. Unless you buy some reinforced carbon/carbon or ceramic rotors this is what will happen…American or not.

 

I also own a 1994 F140. It sits for weeks/months at a time without being driven and there is little to no surface rust on the rotors. Metal composition differences contributing to rust? I haven't had this issue before, mostly owned Broncos and F150s in the 1984 to 1996 time range previous to this Mustang. My wife had a 2006 Hyundai and a 2013, both rusted within hours of a rain.

 

The Oil Life Monitor is calibrated based on semi-synthetic oil, so you should have no issues if you're changing when it says to and using a full synthetic like RP.

As far as the rotors, who cares? It's typical and should be gone within 5 minutes of driving the car.

 

Thanks for the info.