Does top speed change with different trim models ? SR versus ER battery ?

[dtbaker61]

I am wondering if the top speed is limited by motor rpm, inverter current, RW vs AWD, battery voltage, or just by Software....

I have noticed that my MME has limit of 113 mph.... certainly fast enough, but of course I would like to know if it is the same across various models and configurations.... and if it might be one of the magic FirmWare settings that somebody will eventually find out how to remove or change. I will also add that I was amazed how smooth the acceleration was, and the stability of the MME is pretty darn good... It's hard to tell the difference between 75mph and 100, especially with lack of noise or vibration in the cabin !

My first guess is that it may well be an actual hard limit set to protect the motor(s) from over-revving. But we can't see the actual motor rpm, nor do we know what that limit my be. I'm thinking this may result in different top speeds for various configurations of MME with different motor(s). i.e. does RWD have a higher top speed, or AWD, or does that not matter?

Second physical variable would be the SR vs ER battery, with the ER having slightly higher voltage, you might have more available power at same current if the top speed is current limited....

or, maybe its just a software/firmware limit baked into the controller ?

I did find this link
https://ev-database.org/imp/cheatsheet/top-speed-electric-car
indicating that all trims and configurations of the MME are limited to 112, except the GT, which is supposed to be opened up to 124.

so, for those of you who may 'test the limits' for real, I'd be curious to see your responses with top speeds for various configurations. ***disclaimer*** this is for entertainment purposes only, and should only be attempted on a closed course or private road.

I'll start with mine, which verifies the published limt:

MME Select AWD SR = 113 mph
MME Select AWD ER = ....same...
MME Select RWD SR =....same...
MME Select RWD ER =....same...
....same...

......... ok, ok, ok.... all are 112-113 mph limited by motor rpm parameter programmed into motor controller...... GT may be different since motor(s) used in GT may allow higher slightly higher rpm.

I'm sure that 'eventually' there will be controller hacks available.... but would obviously void stock warranty.

- Dan

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[GoGoGadgetMachE]

I can't find any Ford statement on top speed but Wikipedia and Car and Driver both say that it's the governed and the same for all non-GT trims. They disagree slightly on the actual limit.

 

[GoGoGadgetMachE]

also see this other thread Top Speed of MachE | Ford Mustang Mach-E Forum - MachEforum.com

 

[ARK]

I thought it might be artificially limited, though the acceleration really seems to drop off after hitting 100. In terms of protecting the motors or battery though, would a speed limiter effect either of these?

In other words, as far as the amount of strain you are putting on the motors or the battery is concerned, would it matter if you floor it when you are moving 10mph versus keeping the pedal to the floor when are already moving 100mph?

Anyway, I have a SR AWD MME too and it is incredible how fast the battery drops when you are flooring it, seemingly somewhere well short of 1 mile traveled per 1% charge when the pedal is to the metal.

I agree that the Mach-E feels incredibly stable even at very high speeds.

 

[dtbaker61]

In other words, as far as the amount of strain you are putting on the motors or the battery is concerned, would it matter if you floor it when you are moving 10mph versus keeping the pedal to the floor when are already moving 100mph?

it is *most likely* that there is a software/firmware setting in the Controller that puts a clamp on power delivered when speed hits 112 mph regardless of whether you 'floor it' or not. i.e it might deliver more power if you are going uphill at 112, and then reduce the power as you crest the hill and decend such that you never exceed 113.

Anyway, I have a SR AWD MME too and it is incredible how fast the battery drops when you are flooring it, seemingly somewhere well short of 1 mile traveled per 1% charge when the pedal is to the metal.

predictable actually... steady state flat highway at 60 mph probably requires around 20 kW of power to overcome air and rolling resistance. When you 'floor it', you are requesting around 200 kW of power output. The weight of the vehicle, and difference between output and resistance as speed goes up determines your rate of acceleration.

The thing that goes up significantly at higher speeds is the air resistance as that is not linear, it is 'squared' with velocity. If we could actually SEE the kW expended to maintain speed, you'd be shocked how fast it goes up above 60 mph. This explains why if you really want to extend your range when highway driving, you keep the speed down to the speed limit.

 

[SnBGC]

RPM limit for the motor(s).
The smaller motor up front has a higher RPM limit so that is why it can have a lower gear ratio.

 

[Maric]

I still hope Ford offers a OTA performance upgrade to shave off a half second on 0-60. I'll gladly pay for it.

 

[Murse-In-Airy]

AWD ER Premium = 113 MPH

 

[Maric]

 

[dtbaker61]

....just 'testing'.

 

[dtbaker61]

RPM limit for the motor(s).
The smaller motor up front has a higher RPM limit so that is why it can have a lower gear ratio.

mmmm, kinda what I suspected.... changing that parameter would void warranty for sure. ...and no easy way to add a transmission for a 'low' and 'high' for overdrive..... I suppose the internal gear ratio *could* be changed if you really wanted a higher top speed, but it would come at the expense of 0-60 acceleration.

I was just curious.... partly because I have a similar but different limitation with my eMiata which has a MUCH lower rpm limit because it has a brushed DC motor. Stock gearing in that means I top out at about 100mph. Plenty of power available, but rpm limits with a brushed DC motor are down around 5500 rpm before things get risky.

 

[Maric]

....just 'testing'.

I would not be surprised to have lost my license within the year!

 

[dtbaker61]

I would not be surprised to have lost my license within the year!

it is WAY too easy to be going WAY over the speed limit in these MME..... even on side roads! with a little clear space and good sight line, I find myself *significantly* over posted limit if not careful because the MME is so smooth.

 

[moparguy]

My GT maxed out at 124mph.

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