From the IRS
The IRS released the standard mileage rates for use in 2011 (Notice 2010-88). Taxpayers can use the optional standard mileage rates to calculate the deductible costs of operating an automobile.
For business use of an automobile after December 31, 2010, the rate is 51 cents per mile. For medical or moving expenses, it is 19 cents per mile. For services to charitable organizations, the rate is 14 cents per mile. For tax year 2010, the rates were 50 cents, 16.5 cents, and 14 cents, respectively.
Rather than using the standard mileage rates, taxpayers may instead use their actual costs if they maintain adequate records and can substantiate their expenses. In Rev. Proc. 2010-51, the IRS provides the rules for substantiating these amounts.
The IRS also announced that it will stop issuing an annual revenue procedure to update the standard mileage rates and will instead “publish modifications as required” in a separate notice. Rev. Proc. 2010-51 will remain in effect until superseded by later guidance.