If one has say 10 rental buildings and you use one car to service all the properties then how can I avoid entering into Turtotax my auto information 10 times? The auto is a common expence across all the properties.

Each has to be listed separately for each property. Expenses/mileage would vary based on usage for each property.

Peter:

You can accumulate the costs on one car, then average the cost equally over the 10 buildings.

Or you maintain separate logs and enter the actual mileage for each building.

As long as the mileage is not excessive, the IRS will not care one way or the other.

Just a little note. You must claim either actual expenses for the auto OR mileage allowance for the vehicle once you put it into service for your rental property. You cannot switch back and forth from one year to the other. It must be consistent accountability.

Mobea:

I believe the rule is that if you claim actual expenses the first year, you must use actual expenses for every successive year until you dispose of the car.

If you claim using the standard mileage rate the first year, you can switch back and forth each year.

The basis for that policy is the Section 179 accelerated depreciation that can be claimed the first year if you use the actual expense method. The IRS assumes you will claim the higher depreciation expenses in that first year, and they want to make sure you do not get the possible higher depreciation that is factored into the mileage rate in successive years.

If you use the mileage rate the first year, you cannot claim the higher Section 179 depreciation, so the depreciation that is factored in the mileage rate (48.5 cents per mile in 2007) then represents the actual depreciation accrued, more or less.