A curiosity question here. I have a 2014 Kioti 50 hp tier 3 Diesel and a 2006 Yanmar 55 hp tier 3 diesel. Both are non turbo and take about 2 gals of oil with a similar sized oil filter. The Kioti calls for a 100 hr oil change interval and the Yanmar calls for a 250hr change interval. Why such a disparity with similar style engines?