The OEM vs. Aftermarket Windshield Debate

Question Regarding OEM vs. Aftermarket Glass

Dear Glass Detective,

My 2014 BMW X3 with HUD and rain sensor got chip from highway stone impact. My insurance company seemed to indicate 3 levels of windshield glass. OE, OEM, and after market. Two suppliers have given me different information. I pay for 0 dollar deductible, and think I almost got aftermarket glass, when I understood I was getting OEM. Please advise on how to insure I am not getting bait n switched, but also I don’t want to be irrational.


Mark S.

BMW X3 Front Hood

Is There a Difference Between OEM and Aftermarket Glass?

And what about Original Equipment (OE) glass? OE glass is glass purchased by a carmaker for use in the vehicle when it is manufactured.

Thank you for contacting the Glass Detective with your question about whether or not non-OEM (Original Equipment Manufactured) glass is the equivalent of actual OEM glass used for auto glass replacement purposes. I know this is not exactly what you asked but in my opinion, this is the actual issue at hand. You need to know Mark, that before I even attempt to answer this question that whatever I say (or actually write) is going to cause some controversy within the ranks of those who do auto glass manufacturing as well as those who do auto glass replacements. Indeed, in some circles, this is a very sensitive issue. So, I am going to start my answer with a true story which I hope helps shape what I will ultimately say about this subject.

In February of 2000 I bought a brand new Corvette—what would be classified as a C-5 series. For 50 years I had dreamed of owning a Corvette, and when I finally had saved enough money to buy one, I did so. It was gorgeous. A triple black convertible with a six-speed manual transmission. Reportedly it would do 160 miles an hour … I got it up to 130 and while it had the ability to go faster, I didn’t. When I sold it in 2015, it had a little over 18,000 miles on it and had never been driven in the rain or snow and never came out of the garage except to be washed or driven. A tear trickled down my left cheek when I turned it over to its new owner. So like you, I have a “thing” for cars and I would have never thought of using anything but an original GM Corvette part for my Vette.

One afternoon I was at a social gathering and one of the guys there said he had just bought a new Pontiac and that he really loved how quick it was. He went on to state that the quickness and speed it had was because it had a Corvette engine in it. I was a bit offended and quickly said that unless the engine is in an actual Corvette, it is not a Corvette engine. It is a Pontiac engine perhaps made in the same manner with maybe the same engine characteristics of a Corvette engine but unless it was in a Corvette, it was not a Corvette engine. Several of the people at this gathering were car enthusiasts and a debate soon broke out and I was amazed at how passionate some people were about this subject. By the way, I still think I was right but some others did not.


The OEM vs. Aftermarket Debate

I think this whole OEM Glass matter is somewhat akin to my Corvette Engine story. Some purists might say that unless the part went into the vehicle on the assembly line, it cannot be an OEM part because anything that comes after the original part installation is an aftermarket part. Others would say that as long as the part being used for the replacement was made by the same company that made the original part, it is indeed an OEM part. There are variations of these positions but I think you get the picture.

Others go further and say the replacement part would need to be made by the same manufacturer, to exactly the same specs on the very same production line at the same time OE glass parts were being made to be considered equivalent.

Is Aftermarket Auto Glass Cheaper than OEM Glass?

I have been around for a long time and for part of my career, I helped to oversee the daily management of 72 auto glass replacement locations. This OEM question came up regularly and we did offer what we considered OEM auto glass components. We also offered, at alternate pricing, glass that we did not consider OEM.

What is OEM Glass?

So how, you may ask, did you decide which was which? What was the determining factor? I can only answer for myself here and again there are a bunch of people who may disagree … but to me, an OEM part is a part manufactured by the same manufacturer that produced the original part for the vehicle in question and it was made to the same standards as the original part. In this country today, there are thousands of auto parts being sold every day that were made overseas (or maybe even domestically) that claim to be equal to the OEM part they are replacing. In some cases, maybe they are. But I know personally that in some cases, they are not equal to that OEM part that came on the vehicle when it was driven off the assembly line. To some people, based on price and availability, it probably doesn’t matter a whole lot. But in other cases, I think it matters a great deal! I could give you some horror stories about what are often referred to as “knock-off” parts but I’m going to guess that you have heard some of them already.

Manufacturing OEM Auto Glass

I know my response has gotten lengthy already but I want to make just a couple of more statements and then you can go back to driving that very cool BMW you own. First one is this … if a glass manufacturer gets an order for 25,000 windshields for a Chevy something or another, they might decide to run an extra 5,000 windshields (if allowed to do so based on the agreement they have in place with the auto manufacturer) because they know that ultimately they can sell these extras for replacement purposes. They also know that once they are set up to run a given part it is a whole lot cheaper to run a bunch of extra stock parts during the initial run than to set up again for a second run. So are those “extra” windshields they ran not OEM parts?

OEM Glass Factory

Conversely, if some other company also runs that same part to be sold to auto glass wholesalers and replacement shops, is that not (no matter how well it is manufactured) not a non-OEM part? And while I know there are people who would disagree, I also believe that if the original manufacturer runs that windshield a year later it is also an OEM part as long as it is produced in every detail using the original manufacturing process and machinery.  So then, why not check the logo etched into each auto glass part that indicates who made the part and to what standards, and then if you want an OEM replacement, only accept that exact same replacement part that identifies itself exactly matching what was taken off of your vehicle.

By the way, insurance policies vary on what they must pay to replace, so you may want to check that too.

Aftermarket Windshields Can be Just as Good as OEM

Just for the record, many non-OEM parts are every bit as good as an OEM part. One term has become prevalent and promoted by some is the term OEE. This stands for “Original Equipment Equivalent”. This term makes some sense to me but then it becomes a question of “equivalent” to what standard. Who determines if the part is truly equivalent? There are a whole lot of poor imitations that I would not consider using in my vehicle. Deal with reputable suppliers and people you can trust. Maybe that’s the best advice I could provide.

In conclusion Mark, while you have caused me to now miss my Corvette more than usual, I do thank you for contacting the Glass Detective with your questions and I hope this response is of some value to you.

-Glass Detective


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The Glass Detective attempts to answer all questions accurately but cannot be held liable for any information provided or omitted.  You should always work with a licensed, insured and reputable glass shop that can assess your specific needs and local building codes and offer professional services. Never attempt to cut, install, or otherwise work with glass yourself. The Glass Detective answers questions on an informational basis only.

Lyle Hill

By Lyle Hill

Lyle Hill has been in the glass and metal industry for more than 40 years. In this time he has managed glass retail, contract glazing, mirror, architectural window, window film, and automotive glass businesses throughout America. He obtained an MBA from IIT with a focus on Technology and Engineering Management.

Hill is also a columnist for glass industry trade magazines and often called the “face” of the glass industry. He has also authored books including “The Broken Tomato and Other Business Parables,” which is available through Amazon.

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