Maximum RPMs?
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S500 2002
Maximum RPMs?
My wife was a passenger in my '04 E55 when a 944 Turbo took off in front of me. I accelerated just letting the automatic transmission do it's thing. The tach was approaching 6000 and my wife yelled at me to stop or I'd mess up the engine.
I'm sure that the MB computer wouldn't let me blow up the engine and that is why there isn't a red line, but this is my first European performance car and I'm not 100% sure.
Can I blow this engine?
Also, when I started to slow down the engine stayed at 4000+ RPMs for a long time. Even after I slowed way down. Why? The car was plenty warmed up.
Thanks! Sorry if this is a stupid question, but your answers will be used to help me convince my wife that it is okay to accept challenges...
"You're not a teenager and this is not a toy!" She hit me in the head with a news paper!
I'm sure that the MB computer wouldn't let me blow up the engine and that is why there isn't a red line, but this is my first European performance car and I'm not 100% sure.
Can I blow this engine?
Also, when I started to slow down the engine stayed at 4000+ RPMs for a long time. Even after I slowed way down. Why? The car was plenty warmed up.
Thanks! Sorry if this is a stupid question, but your answers will be used to help me convince my wife that it is okay to accept challenges...
"You're not a teenager and this is not a toy!" She hit me in the head with a news paper!
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From: SoCal
MB
no you will not blow up ypur engine, im not sure what the redline is on an E55, but the car will shift for you, not sure why i stayed at 4 for a long time, maybe you were in a very low gear at a high speed, you coulda raced that guy too:p
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From: Australia
Nissan 350Z & Toyota Landcruiser 100 Tdi, i lack a benz...but one day
The E55 has Adaptive driving style stuff, when u punched it momentatilly. computer though u were on a race track so it decided to help u out by keeping it in the lower gear instead of changeing up like a normal fuel saving Auto.
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From: Newburgh, NY
2004 E55
Only trouble with this car is that there's so much power on tap that you can't drive around winding it out, unless you want to stay in 2nd gear. 
Last edited by EDWARD CONROY; Jan 2, 2004 at 07:54 AM.
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From: Palm Beach Gardens, FL
Porcelain Bus
I've wound mine up many times including a couple of track days. This tranny will hold gear right up until the 6500 rpm redline all day long. The wide flat torque band is especiaslly sweet when coming out of medium to high speed turns wen the speed is kept over 50 mph. Still would rather have a manual, but the stock transmission is really nice. I tried a couple of laps using the buttons, but manual shifting of this tranny was no improvement over automatic when comparing lap times.
The engine seems to just be just fine at 6000 rpm, and I suspect it would be fine at 7000, but the brass at MB probably don't want to be replacing parts prematurely. The acceleration right up to the rev limiter is fierce and when the rev limiter kicks in around 157 mph, the car feels like you started stepping on the brakes due to the cutoff of acceleration. I know it's not a great handler for the track, but I highly recommend taking yours out for one track day. The smile on your face will last a few days!!!!!!!!!!!1
The engine seems to just be just fine at 6000 rpm, and I suspect it would be fine at 7000, but the brass at MB probably don't want to be replacing parts prematurely. The acceleration right up to the rev limiter is fierce and when the rev limiter kicks in around 157 mph, the car feels like you started stepping on the brakes due to the cutoff of acceleration. I know it's not a great handler for the track, but I highly recommend taking yours out for one track day. The smile on your face will last a few days!!!!!!!!!!!1
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MBWorld Fanatic!
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From: Vancouver, B.C.
2002 E55 AMG
Re: Maximum RPMs?
Wow, your wife know about cars. I think the redline is at 6500RPM. I don`t think you should worry about it going over the redline, but I did when it first happened in an E500. Wait, there are no markings on the tach. Just let the tranny do the work.
Last edited by MB AMG; Jan 3, 2004 at 02:40 AM.
Senior Member
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From: Newburgh, NY
2004 E55
Sounds like she was concerned, not frightened. My wife is a speed freak. The first time I took her for a ride in my Porsche and got into it, something that always frightened or at least totally amazed, her comment was....don't think you can scare me, cause you can't.
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From: South Florida
09 ML350
Do not worry about over reving the engine, if you do take it to high the rev limiter will come in. The rev limiter is just a safety, the reason for redlines is so the engine is not pushed past its power curve (at high rpm, the power of an engine will fall off very very fast, losing for instance 50% of the power in 500 rpm) for this reason the red line is made so one can use all of the engines usable power. If an engine is reved to high the power loss can be the result of "valve float" (where the valves are opened by the camshaft, but the valve springs are not strong enugh to close the valves before the camshaft comes to open them agian, so the vlavles are constanly open, hense the term "valve float") at this point an engine is drasticly lossing power. Most of us will never expierence valve float due to the rev limiter, but dont worry about breaking any internal components they are made to take the abuse and will not come apart untill very high rpm's are reached.
(I am going to school for this, so I have learned all about it)
Tom
(I am going to school for this, so I have learned all about it)
Tom
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From: S. California
Although going past redline may indeed make you fall off the edge of the power curve, this is not the reason why engineers put redlines on tachometers.
Operating an engine at engine speeds above redline can place excessive stresses on engine components, and often results in valve-train damage.
To prove this to yourself, find a nice manual transmission car, get on the freeway at 80MPH, and shift into first gear. Yes, your car will drastically fall off the power curve -- probably forever. Even with a rev limiter, there is no hope of saving your engine. Rev limiters work by cutting off fuel flow and not allowing you to accelerate past redline. It cannot change the laws of physics and protect an engine that overrevs by improper shifting.
Subman's argument is only true in the case of using engine THROTTLE to hit engine redline. Most modern fuel-injected cars will prevent you from exceeding recommended engine speeds. However, this does not change the actual meaning of an engine's redline. It has nothing to do with power curves.
Operating an engine at engine speeds above redline can place excessive stresses on engine components, and often results in valve-train damage.
To prove this to yourself, find a nice manual transmission car, get on the freeway at 80MPH, and shift into first gear. Yes, your car will drastically fall off the power curve -- probably forever. Even with a rev limiter, there is no hope of saving your engine. Rev limiters work by cutting off fuel flow and not allowing you to accelerate past redline. It cannot change the laws of physics and protect an engine that overrevs by improper shifting.
Subman's argument is only true in the case of using engine THROTTLE to hit engine redline. Most modern fuel-injected cars will prevent you from exceeding recommended engine speeds. However, this does not change the actual meaning of an engine's redline. It has nothing to do with power curves.
Originally posted by Subman
The rev limiter is just a safety, the reason for redlines is so the engine is not pushed past its power curve (at high rpm, the power of an engine will fall off very very fast, losing for instance 50% of the power in 500 rpm) for this reason the red line is made so one can use all of the engines usable power.
The rev limiter is just a safety, the reason for redlines is so the engine is not pushed past its power curve (at high rpm, the power of an engine will fall off very very fast, losing for instance 50% of the power in 500 rpm) for this reason the red line is made so one can use all of the engines usable power.
Last edited by oktane; Jan 9, 2004 at 01:28 AM.
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From: South Florida
09 ML350
No rev limiter will save you from a downshift to 1st at 80mph. Cutting off fuel or ignition in that instance will not do any thing. No you can not change physics, if one would downshift in 1st at 80mph it would not be the engine that is building the rpms but the speed of the car transmited through the transmission to the engine, the car would be pushing the engine into the high rpms (this is not what I was talking about).
Yes prolonged use of an engine at high rpms will cause damage but most engines are made to live at higher rpms then the manufacture has the redline at, this is so the engine is "beefier", for example (and example only) the engineers may have designed the engine to 110% of the normal redline. So they design the engine to withstand revs of 6600, when the tach only reads 6000 and the rev limiter will come in at 6500.
Do we all agree?
Yes prolonged use of an engine at high rpms will cause damage but most engines are made to live at higher rpms then the manufacture has the redline at, this is so the engine is "beefier", for example (and example only) the engineers may have designed the engine to 110% of the normal redline. So they design the engine to withstand revs of 6600, when the tach only reads 6000 and the rev limiter will come in at 6500.
Do we all agree?
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I agree that the red line was not put on tachs to keep one in the power curve, but to protect the engine from an over rev, thus they call it "red-line". As to the margin a certain engine may have over this red line may vary. My Vette rev limiter is bumped up to 7000 rpm, but much more than that for a significant time.....she go pop and I go, what was I thinkin
and I go, what was I thinkin
