These type of threads are always fun. I have found that on main roads your average speed will be 50 MPH. So use that number for planning. One of my fav statements is"on the road by 9 off by happy hour". Lots depends on what you are driving, are you still working? Sad for you if you are. I hate to tell you but RETIREMENT is better than you heard it was.:B I have done as few as 23 miles on a drive day to a max of around 300.
I just use what discounts are available like Passport America, I saved over $600.00 last year with just that discount.Lots of cost depends where you are traveling. Be happy diesel is lower now. I remember filling up in Ca a few years back when the cheap diesel was over $5.00 gal.
Bill