I recently purchased a Snapper zero turn mower with a Kawasaki engine on it. It is time to change the oil as the season approaches and I had a few questions I was hoping I could get answered. I am probably going to go with an SAE30 or a 10w-40. I live in Southeast TN so it does get pretty warm in the summer. My first question is this: is there a huge difference between a SAE30 and a 10w-40 when it comes to small engines. I know the 10w-40 is rated for a wider variety of temperatures. I am planning on picking up a few yards to mow this summer so if it will be better I was leaning towards the 10w-40. My next question is are there differences between oils that are sold just as a conventional 10w-40 and those oils that are marketed as 4 cycle oils. The weights are the same. Not sure if there is anything "special" in a 4 cycle oil. Any help or info would be greatly appreciated.