After a few years of having the IRS steadily raising the mileage rates all the way up to what was 56.5 cents per mile in 2013, they're taking a step back to just 56 cents per mile for business use. So be sure not to overcharge this year or you may busted like these Tea Partiers (I assume). As my wife/accountant pointed out, it's your ass that will taxed more on miscellaneous income by not being able to deduct it. Obviously, check with your accountant as there are different ways you can deduct and charge your mileage. You can find the official document directly from the IRS.