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Why do newer BMW models now use so many chassis codes?

Discussion in 'Off Topic' started by bcweir, May 5, 2010.

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    bcweir

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    The 2006 and later 3-series use a total of 4 different E-codes. The 1-series uses FIVE of them. No wonder BMW ran out of E-codes and had to go to F-codes.

    Can someone please explain to me why BMW went to this maddening system of keeping track of which cars had which chassis codes?

    Case in point is my E32. It had only one chassis code for all 7-series cars from the 1988 to 1994 model year, regardless of engine or body length (i or iL). If you say E32, nearly everyone familiar with BMW chassis codes knows right away you're talking about a second-generation 7-series, regardless of model or body length.

    I am just trying to understand why BMW went from a sensible system of applying just one code for an entire model, to a maddening one that uses as many as five for a single model. At that rate, it will be just a few years before we're into G-codes. :confused:
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    az3579

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    More importantly, why they had to make the codes so random to begin with. I mean, what correlation is there between E21, E30, E36, E46, and E90/91/92/93? Why couldn't it just be E30/E31/E32/E33/E34, in order per generation, for example?

    Come on...
    • Member

    CRKrieger

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    BMW followed the same convention as Porsche did. The consecutive numbers are project numbers in chronological order. Not all projects came to fruition in production as car chassis. If you follow the Entwicklungsnummeren in order, you'll see that the cars are all in introduction/production order, at least up through the E60. After that, I quit paying attention - or caring.
    • Member

    bcweir

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    Before the 2002 model year, it was easy.

    If you said E32 or the E38, everyone knew you were talking about a second or third generation 7-series respectively.

    But today, if you're talking about a 3-series 2006 or later, or a 1-series 2007 or later, the follow up question is WHICH e-code are we talking about? E90, E91, E92, or E93? Are we talking about an E81 1 series or an E83, or any one of the other 3 e-codes?

    I understand the origin of the e-codes. What I don't understand is that previously, different body styles did not merit their own project number or chassis code. An E36 or E46 universally encompassed the entire 3-series line of that generation, regardless of bodystyle.

    It sure makes talking about these cars a lot more complicated.
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    • Staff

    steven s

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    And let's not forget engine codes.
    Why is an E36 328 an M52 and a M3 and S52 (or S50, S54)?

    And that has changed with N motors.
    I'm sticking to owning older cars.
    • Member

    bcweir

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    The M and S engine codes aren't tough to figure out. With a few exceptions.

    M = regular BMW engine, S = M-code engine. Wait a minute! :confused: And now we're dealing with N engines? Aw crud...

    As for sticking with older cars, I'm right there with ya! After the E38 went out of production, BMW lost me as a new car customer. Don't get me started on the hare-brained ideas BMW instituted, starting with the 2002 7-series.
    • Member

    Zeichen311

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    Yes, but how often does it have to be qualified with the body style to discuss specific parts, features or problems? Imagine how tedious that would get within BMW as the company grew and the internal paperwork exploded. Every formal mention of Exx must indicate whether it refers to all or only certain body styles (service bulletins, technical publications, training materials, etc.). Even us lay-folk do the same thing, you can see it all over this forum and others.

    They changed the convention so that each unique vehicle has a unique chassis code, plain and simple. They are after all BMW's internal project numbers...I don't care if they don't care what we think of the plan. :)
    • Member

    bcweir

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    OK, so how do you define a "unique" vehicle vs. a "similar" one

    I suppose I am having trouble considering an E92 (coupe) a "unique" vehicle from an E90 (sedan), since aside from a difference of two doors and some body panel differences, the cars are very "similar".

    The 1-series cars however, would constitute a vehicle "unique" from the 3-series in the regard that no body or structural parts are shared between the two lines. But again, why would a 1-series coupe be considered a unique vehicle from a convertible or the five door when it's otherwise the same car?

    For that matter, why would a standard wheelbase 7-series constitute a "unique" vehicle from the extended wheelbase model? Aside from a longer wheelbase and longer rear doors (and obviously a longer roof panel), as well as some trim differences, aren't the two vehicles otherwise identical? I would think this example would blur the differences between what's a "unique" vehicle and what's a "similar" vehicle.
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    Zeichen311

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    The easiest way is to think in terms of what you can bolt onto the car versus what is fixed at the time of production.

    A 2009 328i and 335i share chassis code E90 (LCI). If you have the necessary desire, bankroll and level of insanity (with most true gearheads possessing any two :)), you can effectively turn a 328i into a 335i simply by spending a lot of money and changing a lot of parts. You might have to go all the way down to the body shell and back again, but it could technically be done and only the VIN would reveal the lie.

    In contrast, you cannot turn an E92 328i coupe into an E90 328i sedan by buying out the parts catalog. The cars are vastly different engineering designs in ways not immediately apparent, mostly relating to the structural characteristics of the unibody. The same is true of the convertible and touring platforms. Thus, these received four different chassis codes.

    This even applies to the long-wheelbase variants of the 7er, beginning with the E65/E66. Once again, if you think in terms of "can't convert one to the other," it makes sense.

    (Before anyone suggests it, hack job aftermarket cutting and welding does not count.:D)
    • Member

    bcweir

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    So did they suddenly start changing the way they built these cars after 2002?

    What you have said is certainly true even before they changed the criteria. I have heard of some E32 "i" owners who coveted the power rear seats on the "iL's", which were unavailable to the "i" cars that were not extended length bodies. So imagine their surprise when someone attempted such a conversion, only to discover that the iL's used a different type of seat track in addition to a different type of rear seat! The rails necessary for the power rear seats were welded to the rear floor pan!

    But my point is, back then, iL's had the same chassis code as an "i."

    So forgive me if I fail to understand the rationale for the E-code criteria, even if I do understand your rationale of "what's fixed" vs. "what's transferable" from one car to the next.
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    Zeichen311

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    They've changed the way they document the cars, not the way they build them.

    You gave a great example of the rationale. Suppose an SIB was published for the rear-seat tracks in the E32, long wheelbase models only. It would be necessary to indicate that in the SIB ("E32, iL models only") so everyone in BMW knew it didn't apply to the short-wheelbase E32.

    Now postulate a similar SIB for the E66. Hey look, I'm done, because the E65 is a different platform. ;)

    Let's be honest: We've all taken to referring to chassis codes because it's cool to use the jargon. You (the "ordinary folk") call it a 7 Series but we (the cognoscenti) know it's an E32. The codes allow a huge company to track their R&D projects and if the codes make sense to them and help them run their business, that's pretty much the end of the discussion. If it now takes more effort for us to sound cool, well, the world ain't gettin' any simpler. Just look at this crazy Intarweb thing. :D
    • Member

    bcweir

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    Wow. Thanks, I think I understand it better that way.

    I still wish it were less confusing, but it at least it's not gnawing away at back of my sanity anymore. Thanks!
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    az3579

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    They must have just used it from 2002 onward, because the E30 for example: the sedan and coupe are differen't. Can't just slap doors on the back of a coupe and call it a sedan, same with the E30 M3, which by bodywork is slightly different because of the rear flares...



    But I supposed it sort of makes thing easier in the end. No longer will we have to ask "so did you get a coupe, a convertible, a sedan, or a touring?"... just say E90/1/2/3. :D
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    tiFreak

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    BMW has actually done it in the past, I know the chassis code for a 3 series hatchback is E36/5, the sedans were E36/4, the Z3 roadster was E36/7 and the Z3 coupe was E36/8, there's a few others but I honestly don't know them because there's really no need to know them, now you do because if you just shorten it to E6X like some people do with the 3-series you can't tell if it's a 5, 6 or 7 series

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