With the rain belting against the window we decided to stay put... so the jobs we keep putting off got done. We have done over 500 hours now with Derwent6 and we will be changing the oil and filter and the gearbox oil every 250 hours. The job is not as difficult as it sounds due to the sump siphon pump which allows you to drain the oil without taking out a sump plug. You have to remove the engine covers and then turn the tap of the sump you wish to drain. The hardest part is changing the filter and cleaning out the bilge with the dropped oil, but again not difficult. We are having terrific thunder storms here today, and it was nice to have the time to watch the cloud formations turning into a storm.