Well if there was a 2mpg diff on a 06 wiht the 6 speed, what the heck would it have been on a 04-08 with a 4 speed?

You will never notice the diff. Except with better accelration w/3.73s No brainer.

BTW With the popular mechanics test the ford had 3.55s.

 

I have no idea what the others would get with the same setup but all i know is mine is getting 14.8 day in day out on my city driving and if Morgan 867 is getting 13.1mpg with the 3.73's and the exact same truck but mine has the 3.55's then there must be a MPG difference. I was told there would be a MPG difference of between 1-2mpg and that seems to add up. Also if people say that the difference between the 3.55 and 3.37 is such a small ratio difference that it wouldn't make hardly any difference to the mpg then wouldn't that also stand for the difference in towing?? As the saying goes you cant get something from nothing.

 

Two people's unscientific MPG reports don't really add up to anything, especially if you're using the computer for MPG and the trucks are still very new.

3.73 isn't that much steeper than 3.55 so it's not going to affect MPG much if any and it really isn't going to give you that much more grunt. It's only 868ft/lbs vs 912ft/lbs in 6th using peak torque for the math. But I'll take what I can get.

Mike

 

Yeah what you say is true and we could both be getting the same mpg but i doubt it. I just think it's silly to have a truck you only tow with a couple of times a year with a diff i wouldnt even need for a trailer i tow everyday that weights in over 8000lb. It's a cheaper truck and it will save you fuel over it's life. There's no doubt at all to go for the 3.73 if ya towing a big heavy trailer day in day out but most people dont. On the sites i work on im the only person out of maybe 25-30 truck owners who even pull a trailer to work. Bet half of them have diffs they dont even need.

 

Well my final thought is get the 3.73 and have nothing to regret. Like I said, I think my truck needs deeper gears and is lighter and only 15ft/lbs behind the 09 in torque. I was also not satisfied with 3.55s in my 94, but that's a totally different type of engine. Needless to say though I won't make the same mistake thrice.

I seriously doubt that MPG will be any different with .18 of difference and any loses on the highway will be made up for in the city.

Mike

 

from what I can figure in the order guide, you can get the optional 3.73 limited slip for the Platinum/Lariat/King Ranch without having to get the max towing package with the big mirrors.

But it does say that if you want the max towing package, then it requires you to pay for the 3.73 gears.

So I think you have things backwards.

 

If there is a real world MPG difference between 3.55 and 3.73, then I would say it would depend on where you live. Maybe where it's flat, the 3.55 might do a little better. Otherwise, not much difference.

Here in hilly western PA, I have a 5.4 3.73LS Screw with 18" wheels and my brother has a 5.4 3.55LS Scab with 17" wheels and we get the same MPG's, around 12 to 13 mpg for 95% city driving.

 

No matter how you order the 3.73 it gets packaged with the max trailer tow package. I had 2 dealers try and get the truck without max trailer tow but ford just wont do it. I guess they think that if you are gonna be towing a trailer that big that you need the 3.73's then they think your gonna need the massive mirrors. My trailer is about 7ft wide and i def dont need trailer tow mirrors. Now if i was towing a 18-25ft trailer or mobile home then there's no doubt i would go for the bigger mirrors and better ratio but people towing them size are few are far between. I even have a 16ftx8ft trailer and i have towed that a couple of times loaded with mdeical Beds and again it does that a breeze as well. The 04-08 company f150's dont tow no where near as nice with that trailer than the 09 i have.

 

^ok, I see what you mean, maybe I mis-interpreted the order guide because the Ford build website confirms that the max tow package is required with 3.73.

The order guide shows the 3.73LS as being optional for the Lariat/Platinum, but it has a footnote that says "required with max tow package". I take that as if you want the max tow package, then you have to get the 3.73 gears (instead of the standard 3.31 gears on the 4x4), not the other way around. Oh well.

 

My local dealer has a sexy as hell '09 FX4 Screw 6.5' box on the lot. To my amazement, the EPA rating is 14 city and 18 hwy. The 4x2 '09 XLT sitting right next to it with the 5.4L and 3.15 reg axle is rated at 20 MPG hwy. The 3.73's are the only way to go unless the purchaser is an ultra MPG watcher.

I was actually considering getting a 4x2 truck with a 3.55 axle and perhaps a 4.6 3V just to have a comfortable and economical cruiser and keeping my '88 for work and play. After seeing the FX4 on the lot and the EPA estimate, I said to hell with that idea. I'm gettin the 4x4!

Tim

 

Funny thing is some engines will get better mpg with higher gears... example: GM 5.3L ( w/4 speed) My bud in charge of a fleet of them and they got better mileage with 4.10s over anythign else. Keep in mind revving the cr@p out of a 5.3L doesnt hurt its MPG. Ahhh the torqueless wonder.

Now the 5.4L is a whole diff animal... 4.10s would hurt MPG.

 

My pal has a truck identically equiped as mine, except two things.
The paint colour, and he has 3.55 gears, and I have 3.73 gears.

We have done a few trips going to the same place, at the same time, and after the trip we have gone and filled up with gas, and its a crap shoot which truck might take a tiny bit more gas.

I really do not think the mileage difference is enough to really measure, they get basically identical MPG.

The drivers foot has FAR more influence on MPG, than the difference from 3.55 to 3.73 does.

 

Guess I am just lucky then, but we have known our sales rep. for about 15 years. When buying new he always sugests ordering a truck if you have any specific requests for what you want on it, and we still come out at least a good if not better ordering it than buying one off the lot. Its good to know an honest sales rep. though because he will do the same for anyone who comes to see him.

 

I have 3.73 on my 05 and it does just as my friends with 3.55 on gas. Before lifting the truck it wasn't uncommon to get around 20mpg on the highway.