I noticed that my 4 wheeler has 50 hours on it but only 465 miles. That tells me that it does a lot of lower speed driving. My brother’s RZR says to service at 25 hours. I’m thinking I might start to do it by hours no matter how many miles it’s been. If the motor is running than the hours are counting whether your putting miles on it or not so I feel like it’s a more accurate way to service.