The general rule in most states is that an employee has no right to mileage reimbursement from an employer. The fact is that the majority of employment relationships are what is called "at will". Accordingly, an employer can hire/fire someone for any reason or no reason at all, as well has increase/decrease salary/hours, promote/demote, and generally impose terms and conditions as it sees fit. Unfortunately for you, this includes the use of a personal vehicle with no mileage reimbursement. So unless this violates existing company policy, or the terms of a union agreement/employment contract, or this situation has arisen due to some type of discrimination, etc, not being given a mileage reimbursement is legal.Note:  You should be eligible for a deduction on your taxes for this, so keep good records.