If I use my car for work - but also for personal use - do I use the split function when there are expenses such as car repairs?

[TomK]

Yes.  When you enter vehicle usage as a job-related expense (subject to the 2% rule), you may deduct either actual costs for repairs, maintenance, etc., or a standard mileage rate ($0.54 per mile in 2016).  In addition, as you go through the interview questions, you will be asked how much you used your vehicle for personal and for business reasons... i.e., total miles driven, personal use mileage, business use mileage.  TurboTax will calculate your job-related vehicle deduction based on your answers. 

Follow the directions in the link below to enter the mileage for the vehicle you used on the job:

https://ttlc.intuit.com/replies/4800418