I have a 06 f150 supercab 4x4 5.4l I have the 3.55 gears and cannot stand them. I have a atv trailer with 3 quads i usually pull and a 3500 pound popup i pull sometimes, The truck is a puke.. It is also has stock 18" chrome wheels. When I hook up to these trailers and pull them my gas mileage drops down to like 9 or 10. It has slower takeoffs and when going up slight hills really downshifts... My ? is If I swap the 355's out to 3.73's would it help out or would there not be a difference? I am wantintg to get trailer performance with gas mileage. I should not even notice those small trailers back there!. Thanks.

 

Yes, 3.55's suck. No, it's not worth the expense to go from 3.55 to 3.73. Make it worth your while and go with 4.10's, you'll be much happier.

 

I agree 4.10's will make it more worth it. Plus if you ever decide to go with bigger tires you are all ready covered.

 

OK If i want to go with 4.10's is this going to give me horrible gas mileage even though the truck is stock? I know If it was to be lifted and running larger tires the gas mileage goes to hell with 3.55's but if the 4.10's were to be installed on a lifted truck running bigger tires it would somewhat bring it back to stock due to the truck not working hard am i right?

 

I have an '05 F-150 truck (reg cab longbed) that came stock with 4.10s. Stock and with the stock tires it got around 13.8 in mixed city and rural driving. Could get around 16-16.5 if I stayed around 65mph. From what I've seen, the city driving will stay about the same but you might drop up to about 1 mpg on the highway. The 5.4L seems ot like to cruise in the 16-1800 rpm range for max economy. The truck is very, very sprightly with 4.10s!!

Basically, you're going to have to pick your poison. You can spend a bunch of money to cure the minor irritation of slow towing that happens 5 percent (or less) of the time you drive the truck, and get slightly worse mileage the rest of the time.

Or, just learn to live life in the slow lane when towing and save your money for something else.

When towing, do you lock out your OD and let the engine rev a little? Better for your trans too.

 

4.10 gears are nice, but do you have $1500-2000 right now to get a set?


If you are only occasionally towing, IMO you would be better served putting that money elsewhere


Btw, the 3.55 to 3.73 jump is pretty negligible. You might feel a tiny difference, but nothing to justify the $$$$.




MPG wise, the 4.10 gears will actually help your city mileage, and take 1-2 highway MPG's. A fair trade in my eyes...I'm going to do a 4.56 swap myself

 

Agree with Tylus, have read in many truck/car magazines with articles about mileage, that in some cases your miles will go up with lower gears. I guess the reason is that you dont have to floor it to get moving, or pull a hill.