Routine Maintenance

[L89DRMR]

Dear Jim,I feel as though you are on the right track as far as changing the engine oil twice a year but if you are unable to put more miles on them,then three and maybe four times a year would be ideal. The key is to get the oil up to peak temperature and if this does not occur,then moisture along with raw gasoline will seriously affect the oil's ability to perform properly. As far as the transmission and differential,once a year would probably banish any moisture which might cause some steel to rust. It seems like cheap insurance to spend a little bit to give you peace of mind. I did go to auto mechanic's school in case you feel I was just making all this up! Hopefully,this will help you decide. Dave