Why wasn't the 2nd generation Z4 E89 not called Z5?

[cruisingdownthestreet]

Hi all,

I'm new to the community. First post. Long-time lurker. I have a 2013 Z4 sDrive 28i =)

I didn't find any information posed by my question, thus encouraging me to create an account and ask it:

Why wasn't the 2nd generation Z4 E89 not called Z5?

Also, does anyone have instructions on removing the (wooden) trim? Of the many threads, websites, and youtube videos, I have found nothing. I'd like to CF wrap it.

[mstevens]

I think there are probably several reasons.

I have driven Z4's for nearly 13 years, and have found them evolutionary (yes, despite some obvious things such as ragtop vs. hardtop, 2 windows vs. 4). Z3 to Z4 was a considerably larger leap than E85 to E89.

Z3 was an anomalous designation in my view. Historically, odd numbered series referred to 4-door cars and even numbers to 2-door cars. That's broken down recently, and I do recognize that the "Z" designations are odd anyway.

I suspect the real reason is something along the lines of "marketing said so".

[bigendbob]

Not a totally new design, some parts common to both cars?
Plus if a car sells well under one mark, then call the next the same. Easier than starting a fresh.

[teezee]

I do not think there are a lot of shared elements with the E85 (see the attached doc page 4 that shows this quite convincingly) and IMO, I think both the exterior and interior of the E89 can be viewed as more than evolutionary, especially the interior. The E89 car shares more DNA with the E90 platform than anything it shares withe the older E85 design, chassis or platform.

Also good quick read here with comments from Heinz Krusche, BMW’s chassis guru:

https://richardaucock.wordpress.com/...assis-secrets/

Some highlights-
1. The basic bodyshell is 25 percent stiffer than before. Vital, said Krusche, for the entire driving experience. This torsional rigidity is the starting point, the vital gear in the cog. Without such a good starting point, he said, it is impossible to make cars drive well.

2. The new Z4 uses the 2-joint front axle from the E90 3 Series. It’s vital, said Krusche, not least for improving feedback to steering. With it, BMW can independently tune directional stability, steering feel and lane change stability. Curing a major flaw of the E85 Z4: its wearisome camber steer.

The rear axle, incidentally, is a development of the old Z4. ‘There was no reason to change it,’ said Krusche.

3. The new Z4 also uses the axially-parallel electric power steering (EPAS) system from the 3 Series. It means the engine isn’t sat on the steering column, so mass is reduced and a purer feel from the road is allowed. The electric motor is in parallel to the steering rack.

The EPAS system has also allowed Krusche to tune the frequencies from the road surface. Basically, you want to isolate high frequencies, but allow through low frequencies. Cumulative learning from the old, oft-criticised Z4 EPAS has allowed BMW to do this.

[Tangent]

BMW doesn't tend to increment model names, (The 3 series has been teh 3 series for decades for example) so the change from Z3 to Z4 is more of an anomaly then them not going from Z4 to Z5 with the second generation.

[teezee]

Still can''t figure out why they are planning on calling the next BMW/Toyota soft top version of the roadster the Z5.

[bigendbob]

Originally Posted by teezee

Still can''t figure out why they are planning on calling the next BMW/Toyota soft top version of the roadster the Z5.

Because the Z4 didn't sell well?