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Is Frequent Use of the Available Power Bad for the Engine?

5K views 67 replies 21 participants last post by  FAR888 
#1 · (Edited)
Sorry to ask such a question guys but I have this small concern.

I drive an ML55 and try as I can, I usually cannot resist the temptation to floor it (not necessarily to the point of using the kick down button) to hear that intoxicating V8 growl.

I am a bit concerned though that I am doing some damage to the engine in some way by doing so.

Are my 'fears' right?

I know of course that this eats substantially into fuel mileage:eek: - I can testify to that!:D

Look forward to your responses!
 
#3 ·
With the correct fuel octane I don't think it'd hurt. I floor it through the first two gears at least once whenever I drive the ML. Of course I always wait until the engine temperature, oil temperature, and transmission are warmed up at an operating temperatures before exceeding 4k rpm.
 
#4 ·
especially with your hand-built engine that is made to put up with high abuse and output, i wouldn't worry about it. when i drive the ML55, i try the best i can not to floor it, but i just cant help it!
 
#9 ·
Engine? As long as you avoid oversquare conditions (high manifold pressure/low RPM) - which is difficult to do with automatic tranmissions - it is very difficult to damage modern stock engines in good tune with brief WOT.

The transmission and u-joints are a whole different story.
 
#10 ·
I believe by flooring frequently you could damage engine mounts and get "clunk" sound coming from the engine bay everytime you drive your ML from standstill. I had this issue before and it got fixed by dealer. But the funny thing is I still floor gas pedal once in a while lol :) , I think I have been intoxicated ...
 
#12 · (Edited)
Those engines have so many protective sensors that even if you'd like -you can't damage them. Do you know the engine will shut down if you keep it overheated for couple of minutes?
Years ago I used to drive 44 HP Volkswagen diesel. With so much horsepower, the gas pedal had only 2 usable positions. My cruise control was a piece of wood stick that kept the gas pedal on the floor. Regardless constant driving at maximum throttle, that thing kept on going and going. I sold it when it was about 15 years old in perfect running condition.
Coming back to ML55 good for you the computer has lowest display of 6 mpg. When I was driving Navigator, that didn't have that limit -the computer was displaying "1 mpg" very often.
 
#22 ·
Those engines have so many protective sensors that even if you'd like -you can't damage them. Do you know the engine will shut down if you keep it overheated for couple of minutes?
Years ago I used to drive 44 HP Volkswagen diesel. With so much horsepower, the gas pedal had only 2 usable positions. My cruise control was a piece of wood stick that kept the gas pedal on the floor. Regardless constant driving at maximum throttle, that thing kept on going and going. I sold it when it was about 15 years old in perfect running condition.
Coming back to ML55 good for you the computer has lowest display of 6 mpg. When I was driving Navigator, that didn't have that limit -the computer was displaying "1 mpg" very often.
It's good know about the protective sensors kajtek1 and thank goodness the ML computer can only read 6mpg as the lowest display.

I think 1mpg as per the Navigator is just obscene!:eek:

Thanks to all of you for your responses - From what I can glean from what you are all saying, it doesn't hurt to indulge in the occasional thrill; but do so in moderation:)
 
#15 ·
I was. If we are talking about just the engine occassional flooring it isn't going to hurt anything assuming that there aren't any existing problems.

You are putting strain on the rest of the drivetrain and mountings which will affect their life but not that of the engine itself. And for a lot of those parts the damage isn't so much from maximum throttle but from changes in force. Going from zero throttle to 100% over a 1 or 2 second period will cause less strain on the systems than just slamming the throttle down. But even this damage is softened somewhat due to the torque converter absorbing energy.

Running WOT for an extended period of time (more than say a minute) would likely cause damage. Diesels can do this. Most gasolines cannot.
 
#23 ·
Heat is the enemy of machines. Thankfully the ML's motor is adequately protected from being killed by heat, and the 55's is built for high speed/high rev driving, so floor it for all it's worth, it won't break any time soon. At 250K+, it could be a whole other story! However, I agree that in your case the scarcity of parts should be considered. Like mentioned earlier, I will be more concerned about the fatigue life of drivetrain components under continuous transient loading. Eventually something will break, something far away from the motor. If I were you, I'd start a small collection of drivetrain components.
 
#25 ·
Thankfully the ML's motor is adequately protected from being killed by heat, and the 55's is built for high speed/high rev driving, so floor it for all it's worth, it won't break any time soon.
Yippee! - That's reassuring to know Darkmann - It's much too much fun to not make liberal use of the available power!

However, I agree that in your case the scarcity of parts should be considered. Like mentioned earlier, I will be more concerned about the fatigue life of drivetrain components under continuous transient loading. Eventually something will break, something far away from the motor. If I were you, I'd start a small collection of drivetrain components
"Eventually something will break, something far away from the motor. If I were you, I'd start a small collection of drivetrain components."

Exactly where I was heading.
Come on guys you give with one hand and take with the other!:crybaby2:

Boca and yourself are absolutely right of course, I should be a bit cautious out here where I can't just nip into the local Mercedes dealership and pick up drivetrain parts and a new transmission. I do intend to stock up on parts when I visit the US again later this year.:)
 
#26 ·
Any engine is only capable of doing a certain....

amount of work before it starts to wear out or fails.

Just the nature of the beast - eg two identical engines, one driven reasonably the other driven hard will both do the same amount of work, but the former will last longer in terms of engine hours.

So bottom line - driving hard does shorten engine life, just depends on how much.

Of course you could have gotten lucky and got an engine which was manufactured to closer limits meaning it's capable of more total work output than an equivalent nominal engine - and vice versa !!

Personally on the ML I'd be much more concerned about some electrical problem than the actual engine :)
 
#27 · (Edited)
I believe if one likes to wander over onto the "wild side" on a daily basis, it is probably a good idea to have the drive train lubrication changed more frequently. Upping the "summer grade viscosity" rating a bit too should be helpful if a visit to the redline is made during those adventurous moments.
 
#34 ·
Did you ever try the Governor setting in your ML55 FAR?
Having diesels, our ML55 sits most of the time and having older tires I am not likely to test it any time soon, if ever. The Mojave desert when I was setting cruise control on our ML320 at governed 115 mph is getting more and more traffic. Not to mention cops getting sport cars and trigger activated radars.
Just missed one couple days ago. My detector didn't sense it, till the cop turned the radar on the gay behind me. Good thing with trailer I was driving slower. :D
 
#37 ·
That new technology is indeed impressive Boca - I believe the new ML550 has more torque and lbs/ft power than the ML55 AMG!

But I think the 'old' ML55 AMG has more power and torque than the new ML350 for those who are not easily impressed!:)

I guess I'm not easily impressed.
But I'm sure it's one hell of a lot faster than a 320.
....or a W164 ML350
 
#41 ·
My preference is to have a torque curve that I can utilize for most of the time, which is low to mid rpm range

I agree, I have the Mazda BT50 3 Liter which puts out nearly the same Nm as my ML,
380Nm available from 1800rpm, all the way thru to 3500rpm, floor it in 4th or 5th gear anywhere from 80km/h up and it takes off like a rocket, top speed is not that impessive at 180km/h but you can't drive that fast on our roads anyway.
 
#44 · (Edited)
Wow guys, that was really technical for me to follow - Even as a lawyer! (Ha ha ha)

My preference is to have a torque curve that I can utilize for most of the time, which is low to mid rpm range
Agreed!

I believe the ML55 and ML500 can muster a lot of their torque at quite low revs - The exact figures escape me but it's out there on the web.
 
#49 ·
Whether it is bad for your engine depends on whether you are
exceeding the performance envelope e.g. overloading.
There is a performance envelope given certain environmental
and input conditions including gas type.
However given it is a MB, the engine management computer
MAY be programmed to rachet down appropriately if overheating
knocking etc conditions are detected but I will be surprised if it does so.
For example, letting the engine overheat is arguably better than shutting
down completely to prevent damage.
 
#54 ·
However given it is a MB, the engine management computer
MAY be programmed to rachet down appropriately if overheating
knocking etc conditions are detected but I will be surprised if it does so.
For example, letting the engine overheat is arguably better than shutting
down completely to prevent damage.

Than you might want to learn, that in ML after you turn the engine off, the small coolant pump keeps recirculating the fluid to prevent "heat points".
 
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