I have a new ranger 6x6 with an 800 motor. I was stunned to find out that the dealer charges $50 for an oil change. The oil change kit is $30 for a filter and 2 qts oil. Any reason why I couldn't use Mobil 1 and get a filter from the local parts store? I haven't looked at it,...is it a roayl pain in the ,....to do this. Thanks for your advice!