I have 2 question on OCI, one is my dad 1995 ford winstar 3.8l he bought it since new, he start it up once in a while and drive 10-20 min ( I would say he start drive it once a month for 15-20 min ). It currently running peak 10w30 + motorcraft oil filter, should I change this every 6 month ? second and this is my biggest issue, my 1985 mustang gt T Top 5 speed 5.0L 46k original miles , the carb been leaking fuel and run super rich, I change the oil 4 month ago and I drove 2 time on that period, since 2 month ago I discover the fuel leak , I been park and havent start it up at all, about yesterday I check the oil, and it had dark on dipstick, I wipe it off, and put it back in, clear fresh oil, but smell alot of gas. I dont plan on working fix the carb any time soon, should I change the oil + filter without start it up ? mabe I put on new carb next summer 2015, for now I just put it on the side. thank you .