Mach1 owners with the Tremec: when do you shift to 6th gear....

[MachNroll]

So I've got the M1 with the Tremec. I've noticed that if I shift into 6th gear under 2k RPM (or under 60 MPH), the engine seems to bog down a bit. Or I guess it "lugs" a bit. So often times I will find myself in the slow lane of the freeway in 5th gear with the RPMs around 2600, which seems like for an extended period it may be hard on the engine. It almost feels like the car needs a "5.5" gear, like a happy medium between 5th and 6th gear. Anyone else notice this with their M1 and at what point to you all shift to 6th gear?

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[v guy]

Yes.

Do not lug this engine in 6th.
GT 4th is 1:1. + 2 od's
M1 5th is 1:1. M1 has one od.

https://www.mustang6g.com/forums/threads/official-gear-ratios-for-the-mach-1-auto-and-manual.158531/

 

[EFI]

've noticed that if I shift into 6th gear under 2k RPM (or under 60 MPH), the engine seems to bog down a bit. Or I guess it "lugs" a bit

It should only lug when you're trying to accelerate at such a low RPM. Just cruising it should not, and if it does it points to other problems. The 10R80 in Normal mode quickly gets up through the gears and I find myself cruising around town at 1200rpm and on the highway at 1700rpm. None of those pose an issue when lightly cruising.

So to answer your question, you should be going into 6th when you know you will be at a constant speed and low throttle input, not trying to accelerate or pass or go up a big hill.

 

[Clint81]

Normally, I only use 6th gear if I'm over 70 mph and I use that as my downshift point as well.
I have experienced the lugging/hesitation you mention and try to avoid that at all costs. I also think that the carbon trap in the 22+ air intakes make it worse.
I have a long history of owning 4 cylinders so keeping it humming above 3k 2.5k is pretty normal for me most of the time. That's where the fun is!

 

[Coastal-Mach]

I only use 6 when over 70MPH on the interstate, with no issues. On a separate note remove the trap and roll on, trap removal causes no CEL or drivability problems.

 

[dpAtlanta]

The Tremic in the GT350's is the same.... there is no pull in 6th, even at 80 - 90 mph when floored.
It may have been done to get the highway mpg rating higher.

 

[RTFM]

not trying to accelerate or pass or go up a big hill.

And if you are attune to your engine and car reaction, you will feel compelled to downshift in those situations anyway.
I instinctively downshifted a few times up hill and was a bit surprised. But that’s why I love the Mach1. We’re fully engaged!

 

[SheepDog]

So I've got the M1 with the Tremec. I've noticed that if I shift into 6th gear under 2k RPM (or under 60 MPH), the engine seems to bog down a bit. Or I guess it "lugs" a bit. So often times I will find myself in the slow lane of the freeway in 5th gear with the RPMs around 2600, which seems like for an extended period it may be hard on the engine. It almost feels like the car needs a "5.5" gear, like a happy medium between 5th and 6th gear. Anyone else notice this with their M1 and at what point to you all shift to 6th gear?

Somewhere around 155 MPH. JK.

2600 RPM is not hard on the engine. You could run it forever at that speed. 6th really is a tall gear (Something like .63) and is really just for fuel economy. I go into 6th anytime Im just cruising above 70 MPH or so.

 

[Roady68]

So I've got the M1 with the Tremec. I've noticed that if I shift into 6th gear under 2k RPM (or under 60 MPH), the engine seems to bog down a bit. Or I guess it "lugs" a bit. So often times I will find myself in the slow lane of the freeway in 5th gear with the RPMs around 2600, which seems like for an extended period it may be hard on the engine. It almost feels like the car needs a "5.5" gear, like a happy medium between 5th and 6th gear. Anyone else notice this with their M1 and at what point to you all shift to 6th gear?

I shift into 6th when steady state on the on the highway at speed. If hitting hills or making any moves that requires accelerating, I will downshift to 5th.

 

[JetGray_Mach1]

6th gear is only for cruising at higher speeds for me, for passing or accelerating I downshift to 5th. Pretty normal for 6th to be a dog its an overdrive gear after all.

Depends on speed of course but around town normally dont go past 5th gear. 6Th when going over 60-70ish.

 

[ShadesOfBloo]

So I've got the M1 with the Tremec. I've noticed that if I shift into 6th gear under 2k RPM (or under 60 MPH), the engine seems to bog down a bit. Or I guess it "lugs" a bit. So often times I will find myself in the slow lane of the freeway in 5th gear with the RPMs around 2600, which seems like for an extended period it may be hard on the engine. It almost feels like the car needs a "5.5" gear, like a happy medium between 5th and 6th gear. Anyone else notice this with their M1 and at what point to you all shift to 6th gear?

What does the manual say?

6th gear with your Tremec is about the same gear ratio as 6th with my Getrag.
It's a teeny, tiny difference, and I'm going into 6th at about 50mph, like the manual says.
My RPM drops down to about 1500, and the engine doesn't seem the least bit bothered. It's not responsive at 1500rpm, but it's not bogging down, either.

The manual for a GT350 said to shift into 6th at 43rpm, so that's taking a higher-strung engine and shifting to less than 1500rpm.

EDIT: Now that I've downloaded the Mach 1 supplement in pdf form, it shows the same shift speeds as the GT350. I guess Ford decided that shift speeds depend on the transmission, not the engine.

...So often times I will find myself in the slow lane of the freeway in 5th gear with the RPMs around 2600, which seems like for an extended period it may be hard on the engine.

Because it's too high, or because it's too low? It's a small fraction of the 7400rpm redline, and Ford was okay with you driving it at under 1500.

It almost feels like the car needs a "5.5" gear, like a happy medium between 5th and 6th gear. Anyone else notice this with their M1 and at what point to you all shift to 6th gear?

I guess the more things change, the more they stay the same, 'cause that was also a thought back in the Fox-body days.
From 4rd gear to 5th the ratios changed from 1.00 to about 0.63, for the sake of fuel economy. That was a big drop in RPM, with an engine that didn't make 200hp at the wheels.
I remember reading that it had been an issue for owners that liked to run laps. If they had a long enough straightaway to reach redline in 4th, shifting to 5th meant the RPM would drop off a cliff and the car might actually lose a couple of mph.
Ford admitted to that as they were explaining why the 1993 Cobra went from a 3.27 rear end to a 3.08: They addressed the problem by giving it a higher top speed in 4th gear.

Now, if you run laps in your Mach 1, you'll likely trip the governor about the time you'd redline in 5th, and that 6th gear drop is a non-issue.

Running laps in a GT, with the Tremec, I see the 3rd to 4rd gear gap as a potential issue.

 

[JetGray_Mach1]

I could care less what the manual says about when to shift. True it wont hurt a thing but that is mainly for optimal Fuel consumption. If I cared about that I would have bought a ecoboost. I don't like car being underpowered like that, shifting at those points feels slow and gutless.

 

[Clint81]

6th gear at 43 mph is pretty laughable for anything other than coasting down a hill.

 

[Coastal-Mach]

I could care less what the manual says about when to shift. True it wont hurt a thing but that is mainly for optimal Fuel consumption. If I cared about that I would have bought a ecoboost. I don't like car being underpowered like that, shifting at those points feels slow and gutless.

Slow and gutless ......that's the perfect description. Totally agree with your comments.

 

[murick]

6th gear is only for cruising at higher speeds for me, for passing or accelerating I downshift to 5th. Pretty normal for 6th to be a dog its an overdrive gear after all.

Depends on speed of course but around town normally dont go past 5th gear. 6Th when going over 60-70ish.

This is basically how I have been doing it myself. The 6th is fine from 80 km/h (~50mph), but it has no pull, basically in the whole range. On the other hand when just cruising at steady 100 mph it is perfect.

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