how much better mileage does the ecoboost get with the 3.55 than the 3.73 rear end? i am thinking about getting a 4x4 was wondering.

 

doesnt seem like the guys with 4x4 and 3.73's get very good mileage.. Alot of reports ive seen is high 13's to low 15's.. Guess it depends on your driving habits.

If you dont need 4x4 then look at a 2wd with 3.55's.. I pop off 18.5 to 20.5 mpgs easily every tank..

 

i need a 4x4. doesn't sound like they get any better than 6.2 raptor.

 

im sure some other guys will chime in that actually owns one..

 

Originally I wanted the 3.73s but could only get them with the Max tow and the elephant ear mirrors that I did not want. Instead I have the 3.55s and looking back have no regrets. With the 6 speed tranny the 3.55s have plenty of low end pulling power and I have knocked off 20+ on long highway trips several times. As far as saying you will get X lower MPGs I can't say. I don't think this number is actually known outside of the Ford Engineering department.

 

i actually like the tow mirrors, but don't tow anything. sounds like the smart thing is to get the 3.55 rear end and get the mirrors added. it also seems hard to get the platinum with the max tow package.

 

I have the 3.73 max tow and I hated the big mirrors till I got the truck. I do 50/50 city, hwy and have been avg 18.6. I have 12k miles and it seems to be getting better or I am stepping on the gas less.

 

i drive 50/50 too and only get 14mpg with the raptor. 18.6 with the 3.73 sounds pretty good.

 

I have a 4x4 Eco super crew 6.5' bed with 3.73. Everything else stock. Mixed driving with mostly city I get high 16's usually. Red light to red light eats the mileage up, especially if you are heavy on the throttle taking off. Highway I avg. 18mpg and change and have seen 20mpg. This last weekend I drove from Twentynine Palms, Ca (SoCal high desert to LA to SD back to LA then back to 29 Palms (that equates to roughly 10 hours of actual drive time for me) and got a little over 18. I drive fairly aggressive and if I can go 75 to 90 mph, I do. Unfortunately, I have a pending speeding ticket to verify my speeds lol.

Every weekend I make the round trip from 29 Palms to LA, Ca. and avg 18 and change. Going west it's against some strong winds (through a corridor that has endless energy windmills for a reason) and going east I gain about 2,500 feet.

When the truck was brand new in the spring I drove from DC to LA and got 17 and change doing the cross country drive on the I40. My trucks mpg has since improved as it got broken in better.

If offroad is something you will be doing fairly often, and if you plan on bigger tires/wheels and more aggressive tread, I would say opt for the 3.73.

Just my experiences, hope it helps.

 

Had a 2012 XLT EB 4x4 157" WB with a 3.55 rear and averaged 18.9 MPG over the 30k miles I had it. Averaged 2500 miles a month. 75hwy/25town.

 

From what I've read here, each individual truck has more mileage variations than just the difference between 3.55's and 3.73's. Other than when towing, I've seen members report anywhere from 12 to 24 mpg with EB's. You may get a 3.55 truck with bad mileage, or you may get a 3.73 truck with good mileage. It seems to be a crapshoot, and I think driving habits will have more to do with it than axle ratio.

Bottom line, if you are worried about gas mileage, a heavy full size truck is the wrong vehicle to buy.

 

My last 5 tanks are in my signature, 90% highway driving. Cruise set at 75-77mph, level terrain. E10 fuel.

 

i have a raptor so mileage is not a big deal. i was just wondering if there was a difference. i plan on putting 275-60- 20s on. if there was a big difference i wouldn't mind a little better mileage. since it doesn't seem to be i guess the 3.73 is good.