155MPH U.S. Limiter... - The Unofficial BMW M5 Messageboard (m5board.com)

Millsap · 11th September 2007, 01:53

Fiction; at least on this '08! I went out today to see what the limit was and was able to QUICKLY display 173MPH on the HUD before coming up on traffic, which forced me to let up. Do I have a Unicorn of US M5's? (this was performed on a closed course)

keang24 · 11th September 2007, 01:54

I think it's vary but most I've seen around 165-170mph. Mine 06 built can go up to 167-170mph even though spec at 155mph.

NickyBlack · 11th September 2007, 01:57

I think the speed shown on the speedometer isn't the exact speed your going. It may be off even up to 5%

bonehead · 11th September 2007, 01:59

Quote:

Originally Posted by Kalik314

I think the speed shown on the speedometer isn't the exact speed your going. It may be off even up to 5%

+1
GPS would probably show closer to 155. I've hit 17.0 before mine kicked in.

My55 · 11th September 2007, 02:05

Quote:

Originally Posted by Kalik314

I think the speed shown on the speedometer isn't the exact speed your going. It may be off even up to 5%

Even if it was 5% off it would still be 9 mph over the 155 limiter
I also had my 550 up to 171 ( on a closed course after Dinan software)

Millsap · 11th September 2007, 02:09

Indicated speed -vs- GPS speed is absolutely different! I noticed that 75 Indicated was 70.5mph actual. It was the same case for my 2000 5 series. It is comforting to know; as I was anticipating 155 indicated. Regardless, that's 278 km/h indicated and factoring the 70.5 actual/75 indicated = correction factor of .94 ~ still results in 163mph actual and it was NOT tapering off?!

trol · 11th September 2007, 02:36

On a drag strip clearly, I got to 17.0 and stayed there. It felt really wierd not accelerating despite having pushed the gas fully.

Dobber · 11th September 2007, 02:42

Ok so that begs the question:

How does the M5 know how fast its going? Does the limiter kick in at a specific RPM range in a certain gear? Does it do so on some other parameter?

If the car knows a more accurate speed than what you see on the speedo, then why in the heck don't they use that for the speedo input?

Millsap · 11th September 2007, 02:50

Tomorrow, I will open the Beast up again with both an on-board GPS (recording max MPH) and if possible, hit the hidden GPS speed in km/h on the hidden nav screen. I've already retired for the evening and enjoyed the company of at least one martini; so I'm done for the evening

Regardless of the outcome, this thing is absolutely amazing! Cheers to BMW NA for offering such a creature!!!!!!

unfoundhorsepower · 11th September 2007, 03:44

If you are shifting the M5 and say run it up to red line in each gear and run it up in 6th to redline your doing 168 or 170 then the limiter won't kick in till your in 7th gear....My son and I road tested a showroom M5 and ran it up to 178 mph out of the show room !!!!!! no limiter....so go fugure ????