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Explaining The Body Structure Of The GM C1 Platform

Earlier this year, GM Authority exclusively outlined how the GM C1 platform supports eight crossover utility vehicles, a circumstance that enables it to achieve massive economies of scale for the Detroit-based automaker. We’ve also explained why the same architecture has slightly different dimensions on similarly-sized vehicles. Now, it’s time to take an in-depth look at the engineering behind the platform.

First, a reminder of the eight vehicles that ride on C1.

GM C1 Platform Summary
Vehicle Model Code Platform Variant Production Facility 1 Production Facility 2 Intro Model Year
Cadillac XT5 C1UL V1 – regular wheelbase, narrow track Spring Hill, TN, USA Jinqiao Cadillac, Shanghai, China 2017
GMC Acadia C1UG V1 – regular wheelbase, narrow track Spring Hill, TN, USA - 2017
Chevrolet Traverse C1YC V2 – long wheelbase, wide track Delta Township, Michigan, USA - 2018
Buick Enclave C1YB V2 – long wheelbase, wide track Delta Township, Michigan, USA - 2018
Chevrolet Blazer (2-row) C1UC V3 – regular wheelbase, wide track, short rear end Ramos Arizpe, Mexico - 2019
Cadillac XT6 C1TL V4 – regular wheelbase, wide track, long rear end Spring Hill, TN, USA Jinqiao Cadillac, Shanghai, China 2020
Baby Buick Enclave C1UB V4 – regular wheelbase, wide track, long rear end - Jinqiao Cadillac, Shanghai, China 2021
Chevrolet Blazer (3-row) C1UC-S V4 – regular wheelbase, wide track, long rear end - Jinqiao Cadillac, Shanghai, China 2021

With the prerequisites out of the way, there are three core pieces that make up the GM C1 platform body structure, as GM Authority learned from various GM engineers. The first is the front-end structure, which covers the front end of the vehicle, and includes such pieces as the engine cradle, firewall/front of dash, instrument panel and center stack mounts. Interestingly, this piece – labeled “A” in our depiction – is common to all vehicles on the C1 architecture. When made at the body shop, this hunk of metal can end up in any of the eight crossovers currently riding on the C1 platform.

The second component goes between the B and C pillars. There are three versions of this piece – one for two-row crossovers (like the XT5 and two-row Blazer), another for midsize-plus three-row crossovers like the Acadia, XT6, three-row Blazer and “baby” Buick Enclave, and yet another for extended-length three-row models like the Chevrolet Traverse and Buick Enclave. This piece is denoted “B” in our diagram.

And finally, the third component starts from the C-pillar and runs toward the rear end of the vehicle. This particular piece is shared much like component “B”, but has some variance. For instance, the GMC Acadia uses a different structure as it relates to this piece when compared to other three-row models such as the XT6, baby Enclave and three-row Blazer.

Outside of these three core pieces of the structure, vehicles that ride on the GM C1 platform also share a significant amount of other common parts and components, including the electrical system, various systems controls, and HVAC componentry. But you wouldn’t know it by looking at the vehicles – which is a (very) good thing. The C1 architecture is platform sharing done right, showing just how far the automaker has come from the badge engineering days horrors of yore.

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GM Authority Executive Editor with a passion for business strategy and fast cars.

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Comments

  1. Alex,

    Why did this get e-mailed to me ?

    I have not even commented on it !!

    No one has yet !!

    This will bring them in by the droves, you are a smart man, as how to get that net traffic !!

    Ready !!

    I relies how this is great, for GM !
    As GM can make more of the same the cost of manufacturing goes down, I get it !!!

    But not ONE !!

    Just please, ONE !!!!

    ONE GM midsized anything ( oops I forgot the C8, the one and only GM midsized vehicle ) with better than average GM blah !!!

    Please just ONE, better than the new GM moto ” Good Enough ”

    All the vehicles are good vehicles !!

    I’m sure they are selling good !!!!

    Just ” Good Enough ”

    Why the C8 ?

    Wasn’t the C7 ” Good Enough ”

    The C7 seemed ” Good Enough ” to me.

    One GM midsized ANYTHING !!

    You can’t tell me, personally, Alex, that you don’t think a better than the average GM blah ” Good Enough ” midsized SUV vehicle, would not sell more numbers, over time, than the C8 !!

    Do you really believe that ?

    Any way glad to see just one more article, on the GM average blah ” Good Enough “Vehicle !!!

    Reply
    1. I get a headache when I see your name. Considering your username, apparently the “good enough” products are enough for you 😉

      Reply
      1. chevyguy20,

        I’m glad you and others get a headache !!!

        And YES Chevrolet has been ” Good Enough ” for me for years !!

        And YES I am still one of those driving GM !!!

        And YES $80,000 I paid for my new GM truck is to much for ” Good Enough ”

        So YES ” Good Enough ” must still be ” Good Enough ” for me !!

        And I am glad GM thinks ” Good Enough ” is the best they can do !!

        I have said this so , so , so , many times.

        It saddens me, that a GMC Denali truck, and a Cadillac sedan, is just ” Good Enough ” in 2019 !!!!

        Reply
        1. Okay but if you were willing to pay $80,000 why would GM change anything?

          Reply
          1. The main reason is, there are three HD trucks allowed to be sold in the US do to a old tax that keeps out true competition !!

            I have said before that if VW was allowed to make and sell a HD truck in the US I would buy one and you GM dealers and customer service reps would never here from me again.

            OK that would not be true as I will be here until I die making sure all know that GM has NO customer support, and the warranty is not worth the paper it is printed on.

            Any way my prediction is in a few years when the vehicles people are paying for fall apart before they are paid for and no one can borrow any more money because they still don’t make enough to own what they have GM will be no more !!

            Who knows, its fun for me though, passes the time !!

            Reply
            1. I’ve owned multiple GM vehicles over the last decade. I’ve never had a problem with a dealer preforming warranty work. But if I did, I would change dealers. Maybe it’s something with you?

              Reply
              1. Jim,
                I to have owned multiple GM vehicles over the last 4 decades !!!!

                I to had never had a problem with a dealer in 3 of those 4 decades !!!!!!

                I thought to myself, self could it be me ?

                It could be me, but what about the last 3.5 decades, I never had troubles there.

                But the more I thought about it the more I thought about it.

                I don’t recall in the last 3.5 decades of GM ownership receiving 3 to 4 recalls per vehicle !!

                H3ll in the last half decade my GM vehicles have been to the dealership more than the prior 3.5 decades !!

                I thought again to myself, self, well it could still be me, BUT I AM A DATA GUY !!!!!!!!!!!

                And the DATA shows, without a doubt or bias that :

                The last half decade of GM vehicles required 400% more trips to a dealership !!!

                There for statistics prove beyond a shadow of doubt, you are 400% more likely to have a problem at the privately owned GM dealerships !!!!

                So it still could be me, not saying its not !!!

                In the last 4 years and two GMC HD trucks and maybe 10 15 trips to the dealership, I have had no troubles !!!!

                Same dealership !!!!

                Only difference is the prior service manager no longer works there !!!

                So there’s that !!!!

                However never a response from GM, I still got screwed, called GM , they did nothing for me.

                Why, you might ask !!!

                Because GM HAS ZERO CUSTOMER SUPPORT !!!!

                The only customer relationship GM has is between the privately owned and operated dealerships.

                Most customers still believe GM can do something for them !!!

                GM can NOT do anything to help the customer !!!

                Why you ask ?

                Because the GM dealerships are privately owned and operated businesses, and GM can not tell them how to operate !!!

                GM can raise the price of parts and vehicles sold to the dealerships, however GM can NOT tell the dealerships what to do.

                But its still probably me !!

                Just like the tens of thousands in class action lawsuits against GM, for lights, wheels, transmissions, screens, etc., its just them !!

                I wonder if there are more people suing GM for faulty parts right now than there are GM dealerships ?

                Must be all of those peoples fault also !!

                Any way, still probably still me !!

                Reply
    2. these (lifelong) comments are hilariously horrible.

      hope you’re NOT this long-winded in face-to-face discussion.

      Reply
  2. When these vehicles become electric, will GM redesign this platform, or use another?

    Reply
    1. I think that since VSS-S is supposed to eventually replace all FWD crossover platforms, the new platform should be able to accommodate gas and EV powertrains.

      Reply
    2. I’m wondering how a valid open ended question such as yours got ‘thumbs down’ votes!!!???

      Reply
      1. gary,

        Just ignore the thumbs up and down.

        It seems that once you form a personal opinion, that hasn’t been approved by GM, here on this site.

        The thumbs down just appear for your name.

        Some here just continue to change their names to try to be another GM opinion, but most on this site are dealers, dealer employees, and GM customer service reps !!!

        Good luck, but ignore the thumbs, they mean nothing here.

        Reply
    3. GM has so many worthy platforms in service, whether it is C1 or GEM, that I wonder if the VSS kitsch were built too soon and will therefore be outdated before wide spread adoption.
      Are VW-like kits even need in an era when semi modular does so much?

      Reply
  3. Thanks for the excellent article! Certainly helps decode the many versions of the C1.

    Reply
  4. This insightful article gives a clear glimpse into how GM operates. It’s about profits first and doing just enough to pass muster. Should work okay for it’s brands except Cadillac.

    All Cadillac SUVs/CUVs should’ve been developed on the Alpha and Omega platforms for perception of exclusivity, performance and premium luxury offerings.

    One can dream and wonder about the what-ifs.

    Reply
    1. Thanks gary,

      Yeah what a dream it is !!!!

      GM making a Cadillac better than the average GM blah ” Good Enough ”

      Wouldn’t that be great AGAIN !!!

      Reply
  5. between my wife and I we have owned 13 GM products (10 Oldsmobile’s 2 Buicks –gm discontinued Olds — & now a XT5 . mileage ranged from 92k to 187k no major engine or trans problems , good enough seems to be great for us ,yes I must say on the XT5 exterior and interior design is right on target But interior trim must be upgraded to Cadillac standard not good enough . we will continue with GM But they must assembled in the USA

    Reply
  6. Reply
    1. The fun part is already Tesla got 150k reservations without even spending a single penny. Look power of marketing. GM will sell ev on rebates and Tesla has people to put $100 without even knowing full product.

      Reply
      1. Elon Musk also said the windows wouldn’t crack. I’d like to think there is that much demand for E-trucks, but I’m not sure I trust his 200,000 figure

        Reply
  7. Hey this is somewhat of off topic but I was wondering if blogs use WYSIWYG editors or if you have to manually code with HTML. I’m starting a blog soon but have no coding know-how so I wanted to get guidance from someone with experience. Any help would be enormously appreciated!

    Reply

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