Does a car loan require collateral?

When you buy a car loan, the car itself is considered collateral. In some rare cases, you can provide another asset as collateral. If you are unable to repay the loan on time, the lender can confiscate the car/or the asset. 

It is also to be noted that the rate of interest offered to you by the lender is dependent on the collateral. Expensive collateral could mean lower EMIs.