I am a self-employed auto mechanic and I have been involved in the automobile business for 50 years. I owned a new car dealership back in the 70’s and early 80’s for 12 years. I can speak from experience.
I disagree, whole-heartedly, that you should never use after-market parts when maintaining your car.
It is more true today, than in the past, that most of the parts of an automobile are manufactured by companies other than the automobile manufacturer itself.
One good example is engine bearings. Clevite is a manufacturer that supplies bearings to the automobile manufacturers and to the after-market. They can be purchased over the counter at most auto parts stores, and usually at a price lower than from a new car dealer. They are even advertised as being used in most of the NASCAR engines.
From 1973 to 1979, General Motors manufactured hundreds of thousands of light duty trucks (pickups). While they were basically good trucks, they had a distinct rust problem. In certain climates, the sides of the box, doors and fenders would “rust-through” in a period of 2 or 3 years. The problem was so wide-spread that several after-market manufacturers began producing the body panels (many of the manufacturers were in Taiwan). The price of a fender from General Motors was more than $200. The price of a Taiwan fender was less than $100. General Motors conducted an advertising campaign encouraging owners of GM vehicles to insist on genuine GM parts. GM stressed that the “fit” of an OEM part was superior to that of an after market part. Quite frankly, I would rather have a fender that had a 1/32″ larger door to fender gap, than an OEM fender with a rust hole.
I am not trying to “single out” GM, but they have experienced more than there fair share of engine design problems. One example is the wide-spread intake manifold gasket failure on 5.7 and 4.3 GM engines. I am just a 69 year old auto mechanic, but I am convinced that this is an engine design problem. Nothing “irks” me more than to perform a repair that is not going to last. I do not use GM gaskets on these engines. Because the problem is so wide-spread, Victor and McCord (two engine gasket manufactures) offer improved design gaskets for these engines.
Several years ago, one of my customers brought his Cadillac DeVille with a 4.6 V-8 engine, to my shop with an engine mis-fire/back-fire problem. Diagnosis revealed that the camshaft had several worn lobes. I called the local Cadillac dealer, using a fictitious name, to see what they would charge to replace the camshaft and lifters. The service adviser told me that the 4.6 was a “bad” engine, and that they did not replace camshafts in these engines. He went on to tell me that they replaced the engines with factory re-manufacturerd engines. I thought that I would have some fun with him so I asked him to give me a reason why I would purchase a “bad” remanufactured engine. To make a long story short, I replaced the camshaft and lifters with after-market parts and the customer drove the car another 50000 miles before he traded it.
I will not deny that there are inferior after-market parts. If you are a “do it yourself” mechanic, stick with name brand parts. Champion, NGK, AC, and Autolite provide spark plugs for both after-market and car manufacturers. Monroe and Moog offer good quality shock- absorbers and front suspension parts. Bendix and Raybestos provide brake pads and lining for both the after-market and car the manufacturer. Before making a purchase, check out the warranty on the product. Do not buy for the lowest price. If you are having your car repaired by a qualified mechanic, trust his judgement. He will not want to do the job a second time without pay because of an inferior part.