If you use your car in the process of performing your work, you may be able to claim a tax deduction for this cost. The ATO accepts two methods for calculating this cost.
Cents per kilometer
Logbook You do not need written evidence to claim using the Cents per kilometer method, but you do need to be able to show how you worked out the kilometers claimed. The logbook method provides a way to determine what percentage of your vehicle was for business use and what percentage was for personal use, with the only business use a deductible expense. This method requires a log-book with odometer readings to be recorded for a continuous period of at least 12 weeks.
Here is an article that gives you information on the latest mileage tracker apps for 2019. Click Here
For more information from the ATO office Click Here