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Should I Buy Car Parts From A Dealership? Never buy these parts

Car parts can be categorized into three segments. Service parts are required to be replaced according to the manufacturer’s recommended cycle to maintain the optimum performance of the engine and braking systems. Replacement parts are parts that have a much longer operational life but must still be replaced in order for the vehicle to maintain proper function. Collision Repair parts are parts that require replacement due to vehicle accidents.

The specialized manufacturing and design of Original Equipment (OE) collision parts are best purchased from car dealerships. Parts such as bumpers, fenders, grills, and bonnets are often available from parts distributors at much-reduced prices, but the fit and finish are not as good as OE parts.

Vehicle manufacturers place a big focus on reusing service parts and replacement parts on successive generations of models or across different model platforms. This simplifies the task of designing new vehicles. Not everything needs to be redesigned as it adds complexity and cost. Let’s look at which parts are better to buy from car dealers and why.

BMW car showroom

Why Certain Car Parts Are Best Purchased From Car Dealers?

When car manufacturers launch a new model on the market via their dealer network they have to ensure that the dealers are stocked with all the parts required to fully service and repair the car on day one of the launch. At the time of public launch, the vehicle manufacturer would have completed thousands of miles of field testing on pilot production models.

The pilot production models are built to prove out the assembly process and to conduct durability and performance testing. These pilot vehicles are subjected to hundreds of thousands of miles of on-road durability tests in order that the manufacturer can be sure that they are launching a defect-free vehicle.

In reality, the quality issues detected on the vehicles must be of a very minor nature and not affect the function of the vehicle or safety in any way. Hence the vehicle manufacturer will have developed sufficient supplier capacity to enable them to stock some inventory of every possible part number comprising the new model.

Design-specific parts such as the exterior body panels have to be kept in stock at key distribution points in a market to ensure that the parts can be supplied within 24 hours of being required. This content is owned by moc.sotuaytsur. Parts such as fenders, bonnets, doors, tailgates, roofs, bumpers, grilles, and mirrors require expensive press tools or injection molding tools to manufacture.

Insurance companies and customers insist on being able to have a collision-damaged vehicle repaired in the shortest possible timeframe. The car dealers are required to carry stock of the collision repair parts on the day that the new vehicle is first sold to the public. These parts will only be available at car dealers at this early stage of a new car’s life cycle.

Due to the high investment cost in the tooling required to make these parts, the cost of collision parts is very high. If there is high demand for these parts in the collision repair market, aftermarket component manufacturers will reverse engineer the parts to produce these parts at lower cost and mostly lower quality.

Insurers will insist that the form fit and function of the parts must be equivalent to OE quality as aspects such as airbag deployment and pedestrian impact protection can be affected by parts of inferior quality.

The suppliers of the OE quality parts to the vehicle manufacturer may be contractually prohibited to supply their parts to parties other than the manufacturer for a period of time. Once the vehicle manufacturer has recouped their tooling investment in these parts they may decide to allow the supplier to supply other parties.

Which Parts Can Be Purchased From Parts Distributors?

Vehicle manufacturers use a strategy of platform engineering resulting in less product and parts complexity in providing a range of different models. The same engine may be used in various different models in a manufacturer’s product offering. The advantage of this is that the manufacturer is not overwhelmed in parts complexity and the expense of lower volume parts.

This is good news for the vehicle owners as it allows parts companies to offer parts of equivalent design and quality but at a much lower cost. Service parts such as oil filters, fuel filters, air filters, cabin filters, spark plugs, wiper blades, brake pads, and discs are designed to a standardized design.

The standard design of service parts allows more suppliers to produce and offer these parts to the market. The competition drives down costs and raises the quality of the parts. Even replacement parts such as clutch plate assemblies, cambelts and timing chains, shock absorbers, and fan belts fall into this category.

The vehicle manufacturer will use as many of the standardized designs for the vehicle in order to save time and money. The original equipment (OE) supplier to the vehicle manufacturer will be at an advantage in offering these service and replacement parts to big box stores and parts distribution companies, but other suppliers will follow.

I’d avoid buying these types of mechanical parts from a dealer if you like to save money on repairs, sure the quality might not be as good as OE, but for the money, aftermarket parts offer great value.

The Right to Repair Act has forced vehicle manufacturers to share more of the propriety design information with suppliers in order to make vehicle parts more affordable to consumers. The result is that so-called aftermarket parts are often similar in quality and much lower in price than the OE part at a dealer.


Propriety design parts such as the exterior plastic and metal body panels are often only available via the manufacturer dealer network. These parts are expensive as the manufacturer and dealers will exploit the limited availability of these parts early in the vehicle’s life cycle.

For high volume models like Toyota Camry, the aftermarket parts manufacturers will rapidly develop a lower-cost alternative, but for low volume models, it may not be worth the investment in tooling required. Insurance companies foot the repair bill for accident-damaged vehicles and they will drive aftermarket parts suppliers to develop high volume, high-cost parts.

The DIY market for vehicle service and repair is many times bigger than the OE parts market. As vehicles age and go out of warranty, owners choose to do services and repairs themselves or via independent repair shops. The result is that Service and Replacement parts are significantly less expensive when not purchased from dealers.

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