Ford Mustang Ecoboost Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 · (Edited)
Hey yall,
So, I've had my 21' mustang ecoboost premium for about 7 months now and I've noticed that on occasion when I'm going down a steep hill or grade while in sport+ mode that my car will rapidly downshift through the gears when I apply the break. I'm guessing the car is doing this with the intention to engine brake, but I was curious if anyone else has experienced this and whether or not it's something that I should be concerned about.

Thank you.
 

·
Premium Member
Joined
·
1,759 Posts
Hey yall,
So, I've had my 21' mustang ecoboost premium for about 7 months now and I've noticed that on occasion when I'm going down a steep hill or grade while in sport+ mode that my car will rapidly downshift through the gears when I apply the break. I'm guessing the car is doing this with the intention to engine brake, but I was curious if anyone else has experienced this and whether or not it's something that I should be concerned about.

Thank you.
That's normal, mine does the same thing at the end of a 1/4 mile run. I just pop it up into drive and brake to slow down. But as I turn off the track and onto the return road, I go back into "S" mode, to keep the RPMs up and reduce the risk of LSPI.
 
  • Like
Reactions: JacksonWheels

·
Registered
Joined
·
7 Posts
Discussion Starter · #10 ·
Yeah, I know. It's one of those words that once coined, can't be uncoined... It seems a bit tired and overused, if you ask me. It makes the engines seem more fragile than they probably really are.
They're often considered fragile because in the instances where we see them blow up, these guys are running mods on a stock block that push the engine far beyond a reasonable limit. So I agree, they do appear to be more fragile than they actually are haha.
 

·
Registered
2017 PP MT DD
Joined
·
1,274 Posts
They're often considered fragile because in the instances where we see them blow up, these guys are running mods on a stock block that push the engine far beyond a reasonable limit. So I agree, they do appear to be more fragile than they actually are haha.
Don't forget beating on the poor thing WOT everywhere from cold.

It makes me shudder just thinking people treat them this way and then go "How could this happen, worthless pile of **** ecoboom engine"
 
  • Like
Reactions: Coyote Chaser

·
Premium Member
Joined
·
1,759 Posts
Don't forget beating on the poor thing WOT everywhere from cold.

It makes me shudder just thinking people treat them this way and then go "How could this happen, worthless pile of **** ecoboom engine"
What I learned from running a factory stock Ecoboost Mustang during my 1st season competing in NMRA.

1) The stock Intercooler saturates at 1000' during a quarter mile run.
2) And it takes 2 hours to return to normal temperatures.

Yet, in my youth, I would beat on my '65 Mustang all night long and the only reason I didn't blow it up, was due to hitting a tree while street racing (it was an exciting 2 1/2 weeks).
 

·
Registered
Joined
·
929 Posts
Hey yall,
So, I've had my 21' mustang ecoboost premium for about 7 months now and I've noticed that on occasion when I'm going down a steep hill or grade while in sport+ mode that my car will rapidly downshift through the gears when I apply the break. I'm guessing the car is doing this with the intention to engine brake, but I was curious if anyone else has experienced this and whether or not it's something that I should be concerned about.

Thank you.
This is an interesting topic that you raise. It appears as though Ford is not the only company that is programming this strategy into their cars. I have a 2017 GMC Canyon pickup with the 3.6L V6 and an 8-speed auto trans. It does exactly the same thing when I'm descending a hill. I thought this behavior was very strange; but I'm used to it now. My hunch is that the TCM (transmission control module) uses input from the yaw sensor to detect a downhill situation. It will then use other inputs to determine downshift characteristics. I also have a 2015 Ecoboost, which is why I'm on this forum, and it doesn't do this. It has a 6-speed auto, that has been used for a long time and probably not subject to the same programming.
 

·
Registered
Joined
·
1,055 Posts
This is an interesting topic that you raise. It appears as though Ford is not the only company that is programming this strategy into their cars. I have a 2017 GMC Canyon pickup with the 3.6L V6 and an 8-speed auto trans. It does exactly the same thing when I'm descending a hill. I thought this behavior was very strange; but I'm used to it now. My hunch is that the TCM (transmission control module) uses input from the yaw sensor to detect a downhill situation. It will then use other inputs to determine downshift characteristics. I also have a 2015 Ecoboost, which is why I'm on this forum, and it doesn't do this. It has a 6-speed auto, that has been used for a long time and probably not subject to the same programming.
Our 2015 Rogue with a CVT engine brakes going down hills. I find it very irritating but there is no way to shut it off. Presumably when doing so it also shuts down the injectors, as our cars do when you lift your foot fully.
 

·
Registered
2017 PP MT DD
Joined
·
1,274 Posts
This is an interesting topic that you raise. It appears as though Ford is not the only company that is programming this strategy into their cars. I have a 2017 GMC Canyon pickup with the 3.6L V6 and an 8-speed auto trans. It does exactly the same thing when I'm descending a hill. I thought this behavior was very strange; but I'm used to it now. My hunch is that the TCM (transmission control module) uses input from the yaw sensor to detect a downhill situation. It will then use other inputs to determine downshift characteristics. I also have a 2015 Ecoboost, which is why I'm on this forum, and it doesn't do this. It has a 6-speed auto, that has been used for a long time and probably not subject to the same programming.
TBH with you I was taught to drive a stick and to go down through the gears when descending a hill and find the lowest gear and use engine braking to assist desent and control the vehicle.
I was also taught to emergence stop WITHOUT ABS and pump to brakes when you felt it lock up.

Anyway I digress

Kids today are taught so skip gears straight from 5th or 6th in to 2nd. That's even if they no what a stick shift.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #16 ·
This is an interesting topic that you raise. It appears as though Ford is not the only company that is programming this strategy into their cars. I have a 2017 GMC Canyon pickup with the 3.6L V6 and an 8-speed auto trans. It does exactly the same thing when I'm descending a hill. I thought this behavior was very strange; but I'm used to it now. My hunch is that the TCM (transmission control module) uses input from the yaw sensor to detect a downhill situation. It will then use other inputs to determine downshift characteristics. I also have a 2015 Ecoboost, which is why I'm on this forum, and it doesn't do this. It has a 6-speed auto, that has been used for a long time and probably not subject to the same programming.
Well now I’m even more relieved hearing other companies do this as well, haha. Also I think you’re right about the reason as to why it decided to engine break. I’ve noticed that when it tends to engine break is when i’m moving fast down the hill and there is a car or two in front of me so what you said would make sense. However, I figured the car was malfunctioning at first because sometimes it really does downshift pretty hard to the point where i’m being jolted from the rapid shifts haha.
 

·
Registered
Joined
·
20 Posts
TBH with you I was taught to drive a stick and to go down through the gears when descending a hill and find the lowest gear and use engine braking to assist desent and control the vehicle.
I was also taught to emergence stop WITHOUT ABS and pump to brakes when you felt it lock up.

Anyway I digress

Kids today are taught so skip gears straight from 5th or 6th in to 2nd. That's even if they no what a stick shift.
Haha. Within the first couple of days of having my six speed I did the now infamous 6th to 3rd downshift by letting it slip out of the gate going to 5th. Ouch.
 
1 - 17 of 17 Posts
Top