subject: OEM and Aftermarket Parts: What's the Difference? [print this page] Sometimes it is a very hard decision on which type of part to purchase for your car. Consumers can feel pressure from the car dealership to purchase "their part" or the OEM, because it is the original part for your car. However, it may in fact be better to purchase an aftermarket part for your vehicle as it will be exactly the same as the OEM at a cheaper price. More so, some aftermarket parts are a better option for your vehicle because they are the improved version of what the car dealership originally offered with your vehicle at the dealership. They are also always the cheaper option.