Question for Unleashed

[RedRocketMike]

In August I filled up my CTS-V with Mobil 1 EP 10w30 (first time using it) and promptly road tripped about 4200 miles in a week, 8-16 hours at a time. Just flat steady cruising. I was not surprised but after returning the oil was still very clean, completely full, and had no gas smell like it normally would (cam). I'm wondering how you think that kind of driving extends what would be my "normal" service interval. Usually I change the oil around 6,000 miles, it's 1/2-2/3 quart low, and is composed mostly of 5-20 mile trips with frequent spirited driving when the oil temp crosses 150. I'm past 7,000 miles now and the oil is still looking great. I feel like that 4,200 miles might be the equivalent of about 1500 of my regular miles. All the steady driving across a mostly flat states, very little load, very few restarts. Has to be easy on the additive package.

 

[UnleashedBeast]

The lubricant in question is capable of up to 15,000 miles or one year, per Mobil 1's specifications of the base oil. However, I'd cap it at 10,000 miles or one year, whichever occur first. When on the interstate, the engine rpm is constant, very easy on the lubricant. With that use, it's very possible to achieve the rated 15,000 miles with that lubricant. My opinion is, if you do not drive this car more than 10,000 miles per year using EP 5W-20, only change the lubricant once a year. There is no point in wasting it with highway miles.