I wonder what their interval is though.

 

I have an '89 Civic and in the owners manual its says 7500k for the interval. They must have known even back then that the oil lasts.

 

In my Fit, I have an Maintainence Minder system, where the Oil Life is counted down from 100%, and a light will come on at 15% saying its time to change the oil. I have gotten about 6-7500 miles out of a oil change. And I switched over to Royal Purple 2 oil changes ago, and it seems i get almost 7-9k out of an oil change now with the syntheic oil.

 

Does your percentage take longer to decrease with different oils?

I switched my Si to synthetic and it's at 15% at ~4,200 miles. Basically same ratio as regular oil.

 

I think with Royal Purple its taking longer. I noticed a difference from dino oil to syntheic oil the first time I used the Royal Purple. I got a little better gas mileage and the engine seemed smoother at the end of that duration of the oil. But my last oil change I think I got almost 7k out of it.