Individuals can deduct some vehicle-related expenses in certain circumstances. Rather than keeping track of the actual costs, you can use a standard mileage rate to compute your deductions. For 2017, you might be able to deduct miles driven for business, medical, moving and charitable purposes. There are significant changes to some of these deductions under the Tax Cuts and Jobs Act (TCJA), so we've outlined the most important things you need to know in claiming mileage on taxes in 2018.