That's the problem. Each truck is a little different. An FL70 would be a used truck since they recently quit making it. So how good a deal would you get on it and what kind of shape is it in. What engine and transmission package you have would effect mileage and maintenance costs. Sometimes where you live may effect insurance costs too. Declared replacement value definately effects insurance costs. How much you pay each month or a cash purchase would also effect monthly expense ETC. Mine's paid for but each month and sometimes each week I get a little surprise in the form of a new tire or new injectors or a new oil pan or who knows what The best rule of thumb is estimate high and then boost it by 25% or more. Then maybe the surprises will be good ones.
Don't forget to add the exciting cost of waiting for days for a part or repairs. In some cases, weeks.
It can quickly turn into one of those, "don't assume too much"
EO archives have alot of stories on this.
If your are prepared, you will do ok.
I have a recon Cummins ISC. It is a 1999 and I have no payments to make on it but kind of figure that a new truck has less upkeep but an older truck has more upkeep. I kind of figure it is a trade off. I have thought that $.50 per mile is about right. Maybe even a little on the high side.
If any of you have seen my blown engine post back in March just want to let you know I am going to court soon. Cost me $3,000 in legal fees but still think things will work out once in court.