[lbc]

I just noticed in my 2006 ML 350/500 brochure that it mentions "Shift into Optimum Gear." This is explained as follows:

Shift into Optimum Gear programming allows one-touch selection of the best gear for maximum acceleration or engine braking by holding a Touch Shift button in the downshift position for one second.

Has anyone tried this and if so what actually transpires?

 

[smarten]

It Down/Upshifts Just as if You Had a Manual Shifter

Yes I've used the feature.

Behind the steering wheel, you will find two toggle buttons - one towards the right side and the other towards the left side.

In theory pushing the right button will upshift and pushing the left button will downshift. But I've discovered they both accomplish up and down shifting depending upon how you toggle.

It takes a little getting used to because you're likely not in 7th gear when you down shift which means you may get thrown into something like 4th gear which will result in a jolt. But the minute you have engaged a button, a number from 1-6 will appear in your dash to the side of "D" to let you know what gear you're in.

Once you select a manual gear, the transmission won't shift to a higher one [although it will shift to a lower one]

I primarily use this feature to downshift into a lower gear when I'm traveling through the mountains and require more torque, and when I'm traveling down a steep road in the snow and don't want to get out of 1st or 2nd gear.

Try it; it's kind of neat and answers the question, "how do I downshift?"

 

[lbc]

I have used the toggles often. However, it seemed to me that the explanation was stating that if I held the downshift toggle for one second, the transmission would select the "best" gear for acceleration. Let say I'm driving and I quickly touch the downshift button and then go into 5th. Then lets say under the same conditions I press and hold the downshift button for one second, maybe it will go into 3rd for maximum acceleration. That is how I interpreted the statement. Maybe I read it wrong.

 

[smarten]

Doesn't your transmission AUTOMATICALLY select the best gear for acceleration without having to press any buttons? So I don't understand what holding down the buttons we're talking about for a second or so accomplishes?

I thought you were talking about selecting a manual gear to defeat the automatic functions.

In any event, it sounds like you've used the toggle buttons so you know what I mean.

 

[morty668]

This feature is really for MAXIMUM acceleration or maximum engine braking. If you are cruising along at 60 MPH in 7th, and you downshift to 6th, you get a slightly higher engine RPM, and therefore a bit more torque and power on tap. Now if your intent is to get your maximum available acceleration, you would pick the gear that will result in an RPM near the redline on your tachometer… this would give you the maximum acceleration potential from the engine. That’s what the transmission does for you if you hold the button down for 1 sec. Also, this gear / RPM selection would result in the maximum engine braking if you are slowing down (but I doubt many people use the feature for that).

This is almost the same as if you press the accelerator pedal all the way to the floor; the computer thinks you want to go as fast as possible, so it selects a lower gear to get the RPM very high for maximum power from the engine. Using the selector button (hold down for 1 sec) just does this a bit quicker and you don’t have to ‘floor it’…

Normally, the computer keeps the engine RPM at nearly optimum levels for gas mileage, ‘normal’ acceleration, and overall healthy engine performance. Most people rarely ever accelerate at the maximum capacity of the engine.

 

[lbc]

OK, apparently it does work if you hold the toggle for one second. It takes you the lowest gear without taking the engine past the redline.

Just wanted to know if I understood the statement in the brochure!

Thanks for your response.