For my everyday use of gas, should I use my company card to use as a tax deduction?
Use company card for any mileage that you are driving for business purposes.
It'll make tracking and end-of-year reporting much simpler.
You may not, however, use the mileage you drive to and from your office (the IRS labels that as commute mileage) as a tax-deductible business expense.
If you're looking for deductions for your business and using a personal vehicle, keep track of mileage. Get a mileage app, Mile IQ comes to mind. (Don't ask me if it's any good, find one you like) Track personal miles and business miles, it comes in handy for the tax preparer. The 2018 rate is 54.5 cents a mile and it adds up quick. There are a few places where keeping all your receipts is advantageous when it comes to mileage, but that's unlikely. The 54.5 cents includes Fuel, Maintenance, and Depreciation. So any expenses associated with those three categories cannot be deducted when taking the standard mileage rate on the Sch C, F, or E. The standard mileage rate is almost always higher.
Do you volunteer? Keep track of those miles. 14 cents a mile.
Going to the Doctor? Keep track of those miles. 18 cents a mile.
Now if you're working a job with a W-2 and your employer is not reimbursing you, you're SOL since 2% misc. deductions are now defunct. That doesn't sound like the case since you have a company card, but it was worth saying.