As there's a lot of knowledgeable people over here in TNF (previous post on different forum wasn't very productive), what are your thoughts on...

What are the main factors that determine "series" model number changes for manufacturers?

For example Porsche 993 to 996 to 997, BMW "E" series, etc, etc. Here one must of course focus on the internal project number (such as 99X "internal" versus 911 for the "market" of the mentioned Porsche example) since a lot of models retain the same public moniker and it's this designations that anoraks use to identify between series or different generations of models.

I believe BMW for example changes series when there's a chassis change, and I think this (the chassis) is the main factor for determining whether there's a change to a new generation. For example the Lotus Elise is now on it's "series 2" version but I think it retains the "111" project number (with a appended 11X for each evolution) because of course the aluminum tub is the same.

Your thoughts on this are highly appreciated, especially if you're in the known for any of famous car series (like BMW and Porsche mentioned above).

Or take some racing examples. McLaren for example. MP4/17D was apparently '80%+' new but didn't a new designation; MP4/18 didn't race, MP4/19 was a derivative of it, but got a new designation...

(Or you can look at the confusion between some Brabham BT42s and 44s... or March tubs that seem to have variously been sold as 741, 751, 761 and 761B, if you believe all the stories!)

It's all down to whether the manufacturer feels like it. Lotus introduced a monocoque F2 car and gave it the same model number as its spaceframe predecessor. Or, as Pete says, March repaint a March 751 and calls it a 761.

I believe that Honda uses a full platform change to determine a new series number. Such as the Civic, which doesn't appear to have an internal designation for the first two generations, then gets "AB" for the third, then the "E" codes for the fourth generation, which had four separate codes (EC,ED, EE, EF) for the different body styles. They're already up to FM I think, for the current US spec Civic.

Mazda changed the internal designation for the MX-5/Miata when the '99 model year cars came out, going from "NA" to "NB", and there wasn't really a major platform change (plenty of mechanical parts interchange), although the body and interior styling was drastically changed, and some engine internals were changed out too. The current all new car is called "NC"

-William

The Marketing Department ;)

Internal project numbers I said Marketing (and the general public) don't give a damn if that BMW is called a E46 or that Porsche is a 993, they just call it a 3 series or a 911!