I'm an independent contractor for GrubHub. I use my own vehicle. They do reimburse us $.40 per mile. Can I still deduct these miles on my taxes?

Yes. if the 40 cents reimbursement is included on your 1099-Misc, you deduct the full 53.5 cents allowed by the IRS.

It the 40 cents is not included, you deduct only the 13.5 cents difference.

Even if the 40 cents is not included on your 1099, the proper way to do it is still include the 40 cents as other income and deduct the full $0.53.5. But, it comes out the same.

More info see:

https://turbotax.intuit.com/tax-tips/self-employment-taxes/filing-taxes-for-on-demand-food-delivery-...

https://driver-support.grubhub.com/hc/en-us/articles/214827926-Do-I-need-to-file-taxes-as-a-Grubhub-...