If you want to know with complete certainty [how much your car loan repayments are going to be every month](/car-loans/car-loan-calculator), a fixed rate will give you that.
The fixed rate you sign up for at the start of the loan won’t change for the duration of the loan. A variable rate could go up or down.
A lot of car loans tend to be fixed rate but there are variable ones out there.
What’s more important than the type of rate is having a loan with a low rate AND the flexibility to pay it off early without penalty.