I have been thinking about switching over to a synthetic oil 5w/40 year around. I usually do filter and OCI at 5K miles now with the 15w/40 conventional oil. The plan would be to run the synthetic for a total of 10K miles with a new filter and 1qt make-up oil (Fleetguard #16035) at the 5K mark of the 10K. I only average 10-12K mileage a year as it is. I have 53K miles on truck now,I'm not really interested in a by-pass system at this moment. Any one doing this procedure or see any problems basically changing it out once a year. The truck is a daily driver, with very little towing.

Tony

 

I have a FPS2500 and I change my oil every 25,000 miles. Have sent two samples in for analysis and both came back clean with no issues.
I would never own another vehicle without one. It has paid for itself many times over.
Been running Mobil 1 Delvac 15/40 full synthetic. Changing to Valvoline Premium blue.... Get the filter.