registering a car

The dealer where I take my car for servicing now wants customers to go online to make service appointments. The last time I tried doing this, on the old system, it got terribly confusing and I gave up and went back to phoning, which has its own difficulties, as there's not always someone available to answer the phone.

But the new system is much clearer about making the appointments, and I did so successfully, but getting to that point was difficult. I had to create an account, which involved confirmations both by text and by e-mail, and then I had to register my car on the system. First they asked for its Vehicle Identification Number, which is a long alphanumeric thing. I had to go downstairs, our to the car, and grab the registration on which the VIN is printed. OK, that done, now it asks for the current mileage and estimated number of miles driven daily. Back down to the car to get the current mileage.

Now, how to estimate daily mileage? I don't have a regular driving schedule, like commuting to work. Some days I do local errands, some days I don't go anywhere at all, some days I go up to the City for a concert. Aha, I know how I'll do this. Below my odometer is a useful figure showing the approximate number of miles driveable on what's left in the tank. I know that, when it's full, it'll say about 350 miles. I always buy gas from the same credit card. If I go through the statements for this year, which are conveniently in one place, I can count up the number of days between fillings (which I usually get when it's down to about 30 miles). Average out the number of days, divide that by 320, and there's the answer, which turns out to be about 25.