I drive my own vehicle to multiple clients houses in a day as a service technician. do I claim fuel costs under "Work Related Travel" or "Motor Vehicle Expenses"?

I am self employed, I have a sole proprietorship. I also exclusively use the vehicle in question for this work during the season of this work. The fuel costs that I have written down are only the fuel costs used to go to these locations. I stop keeping my gas receipts when my work season is done. Once the season is over and I have more free time I use the vehicle for my other (employed) job and personal use. I do not keep gas receipts for this time period.

 

what things should I be continuing or start to keep track of when it comes to this vehicle for future?