Speed limits

Nanu

Veteran
 Sunderland
This may have been asked many times before and the answere may be obvious but why are Z4'S limited TO 155 MPH?
 
I don't think it has been asked before, but many high performance cars are electronically limited to 155mph for some reason, not just Z4s. I'd quite like to know too - is it just an industry standard ? And also, when you can have cars delimited, which makes a huge difference to the top speed of something like an RS6, what's the point of it ? :?
 
Having seen you tube vids, I'm not sure the 3.0 at least is electronically limited, it looks like it runs out of revs. The M/// etc will be different I guess. Anyhow, I've always assumed it is to do with costings - it could be a benchmark and any higher and the insurance will be higher, may have to spend huge extra amounts on tyre development for safety ratings etc ...
 
I have never tried to v-max my Z yet, still To Do... Requires me finding a bit of straight, safe, quiet motorway, probably at about 3am. However I have read on here previously that the M will travel past 155 if it is in 5th gear - I am sure someone has had one up to a GPS indicated 169mph on an autobahn. Seems the limiter only kicks in when in 6th for some reason ?
 
Not sure if it's the same for cars but some years ago our European cousins tried to inflict an 100BHP limit on bikes.
Luckily this did not go through although I think Germany and maybe France did a voluntary limit for a time.

My last bike which I sold to buy the Z was a Suzuki Hayabusa 1340 originally designed to be a 200mph bike because Europe were getting a bit concerned about the motorcycle manufacturers getting carried away re top speeds again the Jap manufactures limited my bike to a top speed of 300kph 186 MPH limited to 6th gear top speed only not power through the gears.
It was possible to deristrict.

Maybe it's a voluntary Euro thing by mainstream car manufactures ?
 
Think that might be it grumpy - also, perhaps a way of the Germans making sure most people don't go completely mental on the Autobahns... Worth a google I think :D
 
I believe that a lot of EU car manufactures out of a non written agreement agreed to a maximum speed allowed on cars. On performance BMs it's 155mph more to do with the Autobahn and being 'responsible' but if like myself, you have a racing license you can request the limiter is removed by BMW. Personally is only have this done if I was going to be using a M3 as a track toy.
 
markeg said:
Mine isn't :D
Shhh... but we can only get to 167... Although you've got a tin lid so you should be good for 174 :thumbsup:

That said, Alpina always err on the low side when quoting things as they like to quote the minimum you can expect and a number of RS' have been found to have over 20 additional BHP when tested so VMAX is also likely to be higher than their quoted figure
 
PerryGunn said:
markeg said:
Mine isn't :D
Shhh... but we can only get to 167... Although you've got a tin lid so you should be good for 174 :thumbsup:

That said, Alpina always err on the low side when quoting things as they like to quote the minimum you can expect and a number of RS' have been found to have over 20 additional BHP when tested so VMAX is also likely to be higher than their quoted figure

:D not been anywhere near there as yet, even with the roof.
 
You could buy the M-drivers package on most M's although I don't know if it was an option available in the UK as in the past BMW UK have decided not to offer it as an option. On the Z4MC it raises the limit to 171mph but doesn't remove it completely. I suspect about 174mph would be about the maximum. For some reason the M-driver package wasn't offered on the Z4MR.

I think the original 155mph electronic limit was a response in Germany to the growing electoral strength at the time of the Green Party. Nowadays this agreement seems to be slipping away as nearly all uber fast German cars now have some sort of extra package that removes or raises the limiter.
 
Over 155mph, there's too much aero lift to drive the car safely. Or so I've been told.


Sent from my iPhone using Tapatalk
 
My limiter was removed when I had it remapped (doesn't affect warranty)..... The e89 is bloody noisy at 160 with a tin roof. I think my M3 handled it a bit better

I think 175 would have been quite easy with 390hp in the e89 but can't say I'd like to do it...plenty of revs and hp left at 160..

but it's all theoretical 8) 8)
 
Adamski said:
Over 155mph, there's too much aero lift to drive the car safely. Or so I've been told.


Sent from my iPhone using Tapatalk

The alpina spoilers (front and rear) are meant to counter that.
 
Bing said:
I have never tried to v-max my Z yet, still To Do... Requires me finding a bit of straight, safe, quiet motorway, probably at about 3am. However I have read on here previously that the M will travel past 155 if it is in 5th gear - I am sure someone has had one up to a GPS indicated 169mph on an autobahn. Seems the limiter only kicks in when in 6th for some reason ?

Drive with me on the way home ;)

I have heard from another forum member that if you are NOT in top gear then the 155 limit does NOT activate.4

Kane
 
I may have seen around 175mph (GPS) in my ///M. The last 10mph were slow in coming though. On OEM springs, the front was very floaty at speeds over c 130mph but this was rectified with Eibachs.
 
I also recall that the 155 limit was a gentleman's agreement a few years ago to quell an effort by some in the German government to eliminate the unrestricted autobahn. To be honest though, When I ran the Zed up to it's 155 limit. Things were happening far to fast to be on a public road. If a car pulled into the center lane I would have been toast. 60MPH on a curvy road is much more fun.
 
Back
Top Bottom