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Discussion Starter · #1 ·
Driving tip for old new owner

2016 GLA 45 AMG.
When going down a long hill 3 miles, it would seem sensible to use the paddles and select a gear to slow the car down rather than wear out the brakes. With a DCT is this wise. Several answers on the forum have not been clear about this
 

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Discussion Starter · #2 ·
Driving tip for old new owner

2016 GLA 45 AMG.
When going down a long hill 3 miles, it would seem sensible to use the paddles and select a gear to slow the car down rather than wear out the brakes. With a DCT is this wise. Several answers on the forum have not been clear about this
My iPad got confused Read “GLA”
 

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Sure, there wouldn’t be any issue. The 7G-DCT engine brakes nicely and the computer is smart.. it won’t let you money shift no matter how many times you flap the paddle lol.

You probably won’t get into the situation downhill, but the car cuts power before it bounces redline on the stock C/S/S+ maps just so you know.
 

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I use the paddles on my Porsche to slow without brake lights when I see a LEO coming up from behind me. It is very effective.

Unfortunately our 2017 GLA45 offers very little compression braking and I've found downshifting slow speed or control decent to be disappointing.
 

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2020 MB GLA250 4MATIC Avantgarde Edition
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I use the paddles on my Porsche to slow without brake lights when I see a LEO coming up from behind me. It is very effective.

Unfortunately our 2017 GLA45 offers very little compression braking and I've found downshifting slow speed or control decent to be disappointing.
I've found it to be much different; as soon as I let go of the gas pedal, it starts decelerating immediately. same if I downshift manually, it mechanically brakes quite noticeably. My father's GLE 53 has a lot less mechanical braking force, it coasts much further and the transmission doesn't brake as much as the GLA does.
 

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Ours brakes dramatically if we are using cruise control, we get over speed when passing, and then I release the throttle. The deceleration is, to put it mildly, abrupt!!!

But simply downshifting gives very little slow down. I wish it did, but it doesn't.
 

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Discussion Starter · #8 ·
I am seeing if I can avoid using the brakes where possible. I have about 1.3 mm on the front roters (discs). I have 18k kms on the clock. i am keeping an eye on the longevity of the brakes. Certainly they are the most powerful brakes I have ever come across.
Thank you for the information.
 

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I am seeing if I can avoid using the brakes where possible. I have about 1.3 mm on the front roters (discs). I have 18k kms on the clock. i am keeping an eye on the longevity of the brakes. Certainly they are the most powerful brakes I have ever come across.
Thank you for the information.
What are you measuring? Front rotor thickness should be 1.3in or 32mm. If you only have 1.3mm of pads the wear sensor should be tripped. There should be a pad measurer in the owner’s manual case.

Brakes last quite a while if you don’t drive hard or do motorsports. Figure around 50k miles/80k km, so you should have a lot of life left from yours with 18k km.
 

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btw: In the USA trucking world use of the engine compression is called "Jake braking." As much higher compression & volume their diesel engines provide more of this braking. However it can often be very noisy and many residential areas outlaw its use.

Back in my manual transmission days I often downshifted for braking assist, especially on highway offramps. Of course you're somewhat trading off clutch wear; there's no free lunch when it comes to Sir Isaac Newton's 1st law. ;)
EV regenerative braking is very efficient however with relatively little motor wear from same.
 

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Back in the days before fuel injection downshifting would cause lean running conditions that could burn the valves.

Proper downshifting required heel and toe operation and or double clutching which few people were taught.

With DCTs, fuel injection, and computer control the world is different. But emissions play a role as wear as engine wear.

My Porsche cuts off fuel and spark to offer generous braking. It also has proportional control on the oil pump with multiple outlets to insure proper lubrication when you reverse the load points on the motor. There might be good reasons why our 2017 45 gives very little motor braking.
 

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btw: In the USA trucking world use of the engine compression is called "Jake braking." As much higher compression & volume their diesel engines provide more of this braking. However it can often be very noisy and many residential areas outlaw its use.

Back in my manual transmission days I often downshifted for braking assist, especially on highway offramps. Of course you're somewhat trading off clutch wear; there's no free lunch when it comes to Sir Isaac Newton's 1st law. ;)
EV regenerative braking is very efficient however with relatively little motor wear from same.
There are signs just outside city limits where I live that say “engine retarder brakes strictly prohibited”, I’m guessing they’re the same as the Jake brakes that you’re describing.
 

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Discussion Starter · #14 ·
It seems as if there is 'no free lunch' as has been said above. As far as I can see it is okay to use engine braking if done gently and set up with a little braking until the controlled speed is correctly. I mean know in advance, not scream into a situation and hit low gears!
What ever drivers do there is a cost. Even storing the car causes some deterioration.
All said it's a great car. So glad I took the opportunity to buy it.
Thank you
 

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It seems as if there is 'no free lunch' as has been said above. As far as I can see it is okay to use engine braking if done gently and set up with a little braking until the controlled speed is correctly. I mean know in advance, not scream into a situation and hit low gears!
What ever drivers do there is a cost. Even storing the car causes some deterioration.
All said it's a great car. So glad I took the opportunity to buy it.
Thank you
Yes, I agree. I don't believe there is any sense in being one of those people that makes you take off your shoes when you get inside, or who won't drive in the rain or snow, or who try to keep everything perfect. Nothing is perfect in this world and nothing can be forever, so we might as well enjoy what we have to the fullest.

I'm not saying that one shouldn't maintain or look after the health and longevity of things, but there is no point in trying to overly protect wearables like clutch or brakes or tires. they are going to need replacement at some point anyways, best not to waste brainpower on them and do something more useful 😂
 

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I have a 2018 GLA 250, I use comfort mode setting with Distronic engaged and let the car maintain the speed. I would bet that the engine computer uses reduced fuel flow and engine brakes the most efficient way possible.
 
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