does tow/haul=overdrive

[martinoledad]

i was just wondering if the Tow/haul button was the same thing as the overdrive button on the older models.

[shotgun]

The best I can figure out it's also different shift points, lock up points, and shift delays. In short, it's a completely different shifting strategy. It also provides engine brakeing.

The manual provides a lot of good information.

[88Racing]

Good job Shotgun!
Ford has copied GM on this one. GM has been running a set up like this since 2003. At least they have on the HD gassers.

[shotgun]

Even a blind squirrel finds a nut once in a while.

Do you think they change the AFR too (richer)?

[Jackpine]

Holy Cow! What a great modification! Makes me ALMOST want to run right out and get a new truck! Then I think of the payments and....

But, it's clearly NOT the same thing as the overdrive button. That only locked out 4th gear. As far as I can tell, nothing else changed.

They could have easily set the A/F ratio a bit richer too, as long as they stayed within EPA guidelines.

And, shotgun, super research! Good on you!

- Jack

[martinoledad]

ok thanks for the info

so is the overdrive automatically on

[shotgun]

Originally Posted by martinoledad

ok thanks for the info

so is the overdrive automatically on

You're welcome.

Based on my towing experience, yes it is. When I'm towing my 4000 lb boat on level roads, I have seen the same RPMs (around 1800 at 65 mph) as when I'm not towing. However, it does take longer on a flat road (with steady throttle position) to get to OD and it doesn't take much additional throttle to get it to drop out.

Note that I do have a 3.73 LS rear end.

[martinoledad]

i have the same rear end

[88Racing]

Originally Posted by shotgun

Even a blind squirrel finds a nut once in a while.

Do you think they change the AFR too (richer)?

In GM's they don't.
Alls it boils down to is different shift strategies and torque management that are both electronically controlled.

[Jackpine]

Originally Posted by shotgun

You're welcome.

Based on my towing experience, yes it is. When I'm towing my 4000 lb boat on level roads, I have seen the same RPMs (around 1800 at 65 mph) as when I'm not towing. However, it does take longer on a flat road (with steady throttle position) to get to OD and it doesn't take much additional throttle to get it to drop out.

Note that I do have a 3.73 LS rear end.

Is there a way to lock the OD out? Possibly a D1, D2 position for the shifter? I can see how this would be desirable if the transmission was constantly shifting up and down. But, I've never been one to subscribe to the adage: "Don't tow with the OD on." If lower gears aren't needed, might as well save gas.

- Jack