I have been changing the oil in my 08 titan every 6 months regardless of mileage since I got it. It has 87k miles and its time to change the oil again. Recently ive been using high mileage full synthetic but I checked my schedule and I only put 1500 miles on it in 6 months. Thats because I have a motorcycle and recently bought a 03 mustang gt that Ive been driving a lot. So, do I stick with the 6 month intervals or go to 12 months. I want to be driving this truck for another 10 years if possible.