Usually the leased vehicle is better (and simpler) as you can deduct the business percentage of the lease fee.
But, the only way to be sure is to do the math. For the owned vehicle you can choose between the IRS standard mileage rate ($0.56 for 2021) or actual expenses. You have the option of using the standard mileage rate for the lease vehicle too. For a full explanation, see: https://turbotax.intuit.com/tax-tips/self-employment-taxes/standard-mileage-vs-actual-expenses-getti...
Most people use the mileage rate for simplicity (and the math usually comes out better). If you don't use the Standard Mileage Rate in the first year, you can never use it for that vehicle.
