Are we really governed at 155mph?
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Senior Member
Joined: Jul 2006
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08 CLS63
Are we really governed at 155mph?
The other day I had the opportunity for a "spirited run" and had the circular screen in the dash set to show the MPH. I kept an eye on it and before I knew it I saw 158mph and had to let off. I would think it would have gone even higher, but are we not limited to 155 without the PP?
Super Member
Joined: Jul 2007
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From: Oldsmar, FL
2005 E55 Wagon, 2017 C63S Cab, 1986 560SL
You're assuming your speedometer is accurate. When you see 175, you'll know you're past the limiter 
For example, Porsche intentionally shows 3mph off on the 996TT. Don't know why and it annoys me, but I get to speed by 3 mph!
For example, Porsche intentionally shows 3mph off on the 996TT. Don't know why and it annoys me, but I get to speed by 3 mph!
Thread Starter
Senior Member
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08 CLS63
I believe all car manufacturer's do that from what I've seen first hand.
Looks like my car decided to do 159mph today before bouncing off of the rev limiter. I was hoping for 160.
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Joined: Feb 2005
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From: orlando, florida. Dr.Phillips, UCF
04 CLK 500, 07 GSX-R 750, S 550, 09 Jeep GC
before i had it removed, my CLK was governed at "130" but according to the Digital MPH readout, i could do 134-135. but no more.
since then i've had it to 162 "in mexico" still pulling slowly but pulling.
since then i've had it to 162 "in mexico" still pulling slowly but pulling.
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Super Member
Joined: Jul 2007
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From: Oldsmar, FL
2005 E55 Wagon, 2017 C63S Cab, 1986 560SL
I don't find my E55 to be off much at all at normal speeds (compared to those police radar things on the side of the road). As mentioned, my 966TT is exactly 3 mph off at all speeds. Very annoying.
Out Of Control!!
Joined: Sep 2004
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From: San Diego
2015 S212
Stock AMG E55s are set at 155, but the ECU has a nifty way of doing it to where you literally do not buckle like you did back in the old days.
If you punch it and pull all the way, the car will max out at about 158. The ECU will do what it can (go lean) to not allow your acceleration to blast past it.
If you steadily accelerate and end up giving it the most gas when you are at about 150ish, it will usually drift up to 162.
As noted, none of this has anything to do with the speedo being off. And also, there is an adaptive factor to it.
I got a tune by powerchip but all it really did was raise my RPMs by 400, so the car was still governed. Granted at closer to 185 but governed none the less.....
If you punch it and pull all the way, the car will max out at about 158. The ECU will do what it can (go lean) to not allow your acceleration to blast past it.
If you steadily accelerate and end up giving it the most gas when you are at about 150ish, it will usually drift up to 162.
As noted, none of this has anything to do with the speedo being off. And also, there is an adaptive factor to it.
I got a tune by powerchip but all it really did was raise my RPMs by 400, so the car was still governed. Granted at closer to 185 but governed none the less.....
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From: Scottsdale, AZ
Mercedes
Unless it is an early version, or powerchip made a mistake, all tunes should remap the Max Speed map. It is a widely know map and tuners should be able to account for it. The RPM limiter is raised as well, but this does not contribute to getting the car to 185.
Out Of Control!!
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From: San Diego
2015 S212
To anyone out of curiousity, how many MPH would 400 rpm add on these cars?
Registered User
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From: ny
2019 s560 sedan
After my tune & mods TTM got a 190 pull thru the top of 6th gear on a Dyno .I never took it past 155 anyway before or after .
If anyone wants to see the vid its on youtube type in tuningtechnology and it will come up
If anyone wants to see the vid its on youtube type in tuningtechnology and it will come up
