Mileage calculation on tax summary.

When looking at my Tax summary for last year I see a vehicle expense category total listed. Is this total the calculated amount of my vehicle expenses based on my business use percent from the mileage tracker listed?  If not, why not?  It would mean the summary is wrong then. If the entire vehicle expenses are added into the total expenses that makes the “total expenses” incorrect. Also when I look at my tax summary on the IOS app it says my vehicle deduction based on my mileage is 6% and when I look at my tax summary on the web site it says my vehicle deduction based on my mileage is 31.6%. Big difference. Why the discrepancy?