hey...my Honda Navi is going into hibernation & shortly after waking her up next spring the warranty will be used up; ssooo...that opens up possibilities to move away from the factory spec of 10w-30 engine oil and using gear oil in the rear differential; would you continue with 10w-30 engine oil (in my case a frankenbrew of Star-Fire full synthetic sn pcmo & conventional Yamalube sj small engine oil) OR switch over to a dedicated gear oil (80w-90 conventional or 75w-90 synthetic); target interval for changes is 2000 miles...