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Editorial: The Perceptual Confusion of BMW’s Platform Philosophy and FWD

Interesting | July 7th, 2011 by 26
BMW_platform_matrix

We’ve been down this road before, but as we near the approach of the first production FWD BMW, there appears to be a bit of …

We’ve been down this road before, but as we near the approach of the first production FWD BMW, there appears to be a bit of misunderstanding of how BMW achieves a FWD platform. It is not named UKL (Untere Klasse) – that is a German acronym that roughly translates to ‘sub-compact’ class. Rather it utilizes the same BMW platform matrix that the F20/F30 1er and 3er will use. How can they do that? Well when they planned for common architectural features – they also planned for architectural flexibility.

First, here’s what I believe BMW is up to. I have no confirmation of this. And no one in BMW, that I’ve had conversations with, likes to talk about the ‘platform matrix’. That’s understood, because most people immediately think of the old GM A-body cars when you mention ‘platforms’ (talk about the same sausage!).

Editorial: The Perceptual Confusion of BMWs Platform Philosophy and FWD

A good way of explaining the ‘platform matrix’, I believe, involves not thinking about the body of the car, but rather suspension components, engines, electronics, and other items that can be shared (many the customer can’t see). I believe that BMW has economic reasons to use the ‘platform matrix’ philosophy.

BMW doesn’t build a million of any given vehicle (like Toyota does the Corolla) and they’re constrained in getting the economies of scale to play out in their favor. So they have to be very smart about how they utilize the resources they have. And also, BMW is forced to play in the premium segment because they don’t have the same economies of scale that a Toyota, Ford, or GM have.

So how do the cars that BMW offers fit into a ‘platform matrix’ philosophy? The picture I cobbled up shows how. BMW, I believe, has inherently two ‘Platform Matrices'(there are more, but it gets pretty complicated with new and old ‘platform matrices’ in production at the same time).

One is for large cars and the other for everything else. I tried to show how the various models are arrayed. But, what is important is the ‘everything else’ platform matrix (I think it’s known internally as L7, but that’s based on one hit from an old web search).

Also of note is the fact that engines and transmissions (not shown) are shared. The two platform matrices shown may also share some common components between them, think steering racks, HVAC units, etc and that’s why I’ve shown some overlap between the ‘large’ and ‘small’ platform matrices).

So how does this relate to the so-called UKL platform. Well that’s actually the beauty of what BMW has created in this go around; the L7 platform has a ‘flexible firewall’ location. So BMW can build AWD, RWD and FWD from the same ‘platform matrix’, they aren’t locked into transverse FWD only. And that’s where people are getting confused. They don’t seem to get the idea that BMW’s L7 platform matrix has this flexibility built into it.

And that’s why I get so amused when people start screaming about the Z2 being FWD. It doesn’t have to be (and BMW would be foolish to make it FWD). Here’s my argument (again) against FWD in a two seats sports car. There is no packaging requirement to use FWD, after all it’s two seats only for gawd’s sake. And you aren’t expected to use them for shopping, etc.

The only reason you make a FWD sports car is if you have no other small car platform to build a car from (and even then the smart companies build mid-engine two seaters reusing the FWD drivetrain components).

So BMW isn’t constrained to using FWD for it’s small cars, because it’s smart enough to have designed the L7 platform matrix to accommodate a flexible firewall location. They will use FWD where it makes sense in their UKL offerings (A & B class cars), and retain RWD and AWD for the other models (including the F30 3er which is based on the L7, and certain models of the F20 1er, etc).

In the grand scheme of things, BMW has hit on a solution for maximizing their return on investment in components. They also have the production capabilities to pull off building different cars from a set of components, thanks to outstanding pressing processes and clever engineering.

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