I bought a turf tiger with the kaw 29 dfi engine last week and they told me to change the oil and the filter at the eight to ten hour mark to get rid of the breakin oil. my question is can i use schaeffer 15w-40 synthenic oil in this engine? i have schaeffer oil in all of my farm equiptment and vehicles and i have good luck with the oil. i just didn,t want to buy different kinds of oil. the manual said to use 30wt or 10w-30 or 10w-40. i don,t think the oil will be too heavy, but i would like some different views on this subject, but i don,t want to void the waranties on the engine. any information would be appreciated.