Originally Posted By: Wolf359
Originally Posted By: d00df00d
There's no question that the people who design cars don't get everything right. The question is, if someone DIDN'T design the car, how likely are they to do a better job? If they did, how could I as an amateur even tell? And if I didn't like the way the designers did something, such that I'd want to change it with aftermarket parts... why on earth would I have the car in the first place?
That's why I always go for cars that are fit-for-purpose (and budget) from the factory, and service them with almost nothing but OE parts, with VERY few exceptions. Had the best luck that way, by far.
BTW, there's an important difference between OE and OEM:
OE = Original Equipment = The exact part that came on your car, or an updated version from the car's manufacturer.
OEM = Original Equipment Manufacturer = The "same" part made on the same assembly line by the same company that makes the part for the car manufacturer. Could be identical, or could be slightly off.
Usually -- and with some notable exceptions -- OE has the best performance and quality control, followed by OEM, and then other aftermarket stuff. That's why pricing and warranty coverage -- again, with notable exceptions -- generally follow the same trend.
Here's a few things you're missing. The people who design the cars design it to a certain budget with all sorts of compromises. The aftermarket sees the results of the failures and can design a better part. The manufacturer has certain constraints they still have to abide by. Case in point was sway bar links. Ford use to make them out of plastic. Meant they were weak and broke pretty reliability every 2 years or so. I got aftermarket metal ones. Didn't end up replacing them. They probably had to be plastic to keep the weight down. Same thing with their water pumps, at one point, they used plastic for the impellers. I'm sure that kept the weight down, but they tended to break and fall apart. Aftermarkets didn't care about weight restrictions or CAFE so they were metal ones. OEM all the time can be a flawed mentality. You can have the same problem with OEM tires, lousy grip or whatever issues due to CAFE. Aftermarket doesn't care about worse gas mileage.
I did take care not to speak in absolutes and repeatedly mention exceptions.
I used to own an E36 M3, so I'm well acquainted with parts that sucked from the factory and were fixed in the aftermarket. I'm also running a couple of non-OE parts on my current car because I made a careful decision to change certain things about the car (and accept the negative consequences).
The point here isn't whether exceptions exist; the point is the overall trend, which is clear -- and on which you and I seem to agree.
Originally Posted By: Wolf359
But yeah, I'd agree with the OE push. It's funny with Mercedes, Wahler makes their thermostats and when you buy the part, the spot where you'd see the MB logo is burred out. Still an OE part, but cheaper because it's not OEM.
That's funny.
AFAIK, whether it's completely equivalent to OE depends on why it's not being sold as such. If it was a production overrun that was still within MB's tolerances, or if Wahler just used the same (or better) tolerances themselves, then it's equivalent. If it wasn't suitable for the MB brand because it somehow fell outside of their tolerances, then it may not be.
Either way, still a dang sight better than a parts store special.