Do I need to also save my gas receipts for my truck, or just record the mileage. I would assume you couldn't use gas receipts since there would be no way for the IRS to prove that you were not saving gas receipts for all of your cars. Also, with recording the mileage, are there special rules the IRS wants me to follow? Do I need to record the start and stop mileage or just the number of miles driven that day? Do I need to record the addresses I visited or just the date? Anything else they require as far as documenting your vehicle use? Thanks.