Just found some interesting information. Going to the 2008 5.4L/4 speed combo from a newer 2010 5.4L/6 speed combo is like losing 1st gear almost exactly!!

If you had a 2004 - 2008 5.4L, 4 speed with 3.55 axle, 1st gear final ratio is the same as the 2009 - 2010 5.4L, 6 speed with 3.73 axle, 2nd gear final ratio!!!

It's like you lose 1st gear completely with the 4 speed trans. That would make a HUGE difference in acceleration from a stop!

Also the 4 speed trans 2nd gear is nearly the same ratio as the 6 speed trans 3rd gear.

No wonder why people in new 2011 drive-trains comparing against their old 2008 and previous 5.4L/4 speed combos notice such a huge difference in acceleration. All you have to do is a manual 2nd gear start to feel how a 2008 felt like accelerating from a stop.

No wonder why a 2009 F150 5.4L is a whole second quicker than a 2008 F150 5.4L from 0 - 60 mph.

4 speed trans ratios:

1st gear = 2.48
2nd gear = 1.56
3rd gear = 1.00
4th gear = .70

6 speed trans ratios:

1st gear = 4.17
2nd gear = 2.34
3rd gear = 1.52
4th gear = 1.14
5th gear = .86
6th gear = .69

See here

 

Mike, I have a spreadsheet I use with all the half ton axle/trans ratios and torque too. Easy for me to compare 4-spds vs. 6 with different axle ratios or across brands.

First gear of an EB 3.73 has twice the torque multiplication of my truck, and power comes on stronger, at lower engine speed, and last longer vs. mien that runs out of steam before 5000rpm.

 

The 6 speed transmission technology was indented for improving fuel economy while continuing to give reasonable low end acceleration.

My 2010 XLT Screw 4.6 3V with 3.55:1 gears would out run from a dead stop my '04 STX regular cab or '07 XLT Screw both with 4.6 engines with 4 speed transmissions.

Don't forget to consider increase of hp. I don't know about the 5.4 but the newer 4.6 engines have more hp and torque than the '04-'08.

 

The 4.6 2v from '04-07 had 231bhp
The 4.6 2v from mid-'07-'10 had 248bhp
The 4.6 3v from '08-'10 had 292bhp

 

My 2005 5.4 with a tuner would run right with my stock 2011 in a quarter mile. You must have a custom tune to take advantage of everything Ford left on the table. I seriously doubt they left as much to be gained on the 2011, with just a tune.

 

I had a 2005 XLT, 4x4, 3.55 LS rear, short box / regular cab with the 5.4 and a 4 speed automatic. I traded it in on an identical truck - except the 2010 has the 4.6 with the 6 speed and a 3.73 LS rear. I will guarantee you that the new truck will run anway and hide from the old truck in a drag race. The 6 speed makes all the difference in the world.

 

Not only that, but the 4.6 3 valve has almost as much power as the older 5.4 3 valve.

 

My 2004 F-150 with a 5.4 3v = 300hp/365ft lbs (3.73)
My 2011 F-150 with a 3.5 twin turbo = 365hp/420ft lbs (3.55)

I think that's the biggest difference.

Does 2 more gears help in the trans? Sure, but not as much as 65hp/55ft lbs.

 

Yup, I've done a hard 2nd gear start in the EB just to make a fair comparison. I would put an EB starting in 2nd against a 5.4 starting in any gear with any trans. I've owned both, the EB is the better motor. The extra gears only stretch the lead.

 

Nope. Almost twice the wheel torque in first gear and more in second of an EB6-spd than 5.4L 4.spd.

 

My '07 and my '10 XLT Screw with a 4.6 had the same 248 hp. I was surpirised how much more torque my new '10 seems to have with the 6 speed.

 

You sure about that? I didn't know you could get the 6 speed with the 4.6 2 valve........

 

Unless it was special order, I don't think you could...

 

I bet you would be surprised if you actually raced them and I don't see the gearing difference making that big of a difference. I was looking at a 2010 F150 xlt crew cab 4x4 with the 3 valve 4.6 and 3.73 gears,I was able to keep it overnight before making a decision. Driving it around, I was impressed with the added power and my buddy with an 07 FX4 thats bone stock came by and we decided to run the two trucks against each other. Off the line the 2010 would jump ahead about a truck length but the 07 would catch up and pass me everytime. From a roll it was even closer with the 07 winning slightly everytime. The 07 is a heavier truck and had a passenger compared to me being the only one in the 2010.