As of today my del sol I have listed is at a 1 year OCI on 5w20 PU and a Purolator PureONE filter with a filtermag attached. In that year I have put exactly 5,010 miles on the oil. Every mile of that is highway. Not one single short trip and all at 50+mph. The oil level is exactly as it was filled, perfection no top off needed. The oil isnt black but looks like its been doing its job, definately has a good color to it. The ODO is at 107,750 and Im really wanting to drag out this oil all the way to 110k. In your opinion should I feel comfortable to drag out this change longer than the year? Its going to take maybe another 6 months to get the mileage Im looking for. I have plenty of oil and filters in my stash so its not a huge deal to change it. I just dont have much PU left and I feel like I want to get my money out of this expensive oil.