As the title states, I am eyeballing and researching the 4.10 vs 3.73 rearend on the FX4 ecoboost. What kind of mileage difference are we talking towing and not towing. I've seen alot of posts that state the 4.10 is overkill for the ecoboost.

Are we talking 1-2 mpg difference or is it around .5-1mpg difference?

Truck will be used to haul a 3500lb fish/ski boat regularly and occasionally(once or twice a year) a 9500lb Jayco 32ft trailer. Outside of that it will be used around town for my computer business.

 

I would think the 4.10's would drop the mpgs atleast 1 to 2 mpgs.. I'd go with the 3.73s

 

Unless you plan on putting bigger tires on it I would avoid the 4.10s for what you are wanting to do. You don't list a location to know what kind of terrain you will be seeing but for the boat it doesn't matter. Any of the engines with any of the axles in a F-150 will not have problems with that much weight. I notice my mileage is much better when I can keep the truck under 2.000 RPM while cruising down the freeway. It seem the turbos really start to spool up between 1,500-2,000 RPM and with that extra fuel is used anytime there is a change in load. With my 3.55s I can run 75MPH and stay around 1,800RPM and still get high teens easily including some running around in town. The 4.10s will be a lot of fun but I think they would be overkill behind that motor. Now, if I had a 5.0 I would want them since it is fairly rev happy.

 

Aren't you the guy who has been crapping all over the EB???

 

I have been known to state problems about the EB, but Ford has finally resolved most of the issues. Just because I had a problem vehicle from Ford doesn't mean I'm gonna hold a grudge or blacklist them. There are things I love about the f150 and quite frankly my family has been buying Fords for generations. I'm entitled to say I had a Platinum f150 EB that was basically a lemon, but that was one truck not all of them.

The 4.10 vs 3.73 debate is due to the ability to tow, my question is about mileage difference between the two ratios. I can get either a 4.10 or 3.73 for almost the exact same price with current discounts and packages Ford is offering.

 

Regardless of the axle ratio, you should get one with both the max tow and HD payload package (8200 GVWR) to tow that Jayco. The chart I'm looking at shows with the 157" WB and EB, this is only available in 4x4 and MAY only be available with 3.73's.

http://www.ford.com/trucks/f150/specifications/payload/

http://www.ford.com/trucks/f150/specifications/towing/

 

If you have any plans to add larger than stock tires, I would go with 4.10s. 2mpg is not a large hit financially. I am of the opinion, if you buy a truck you want it to pull as well as possible.

 

Normally I would agree with you 100%, but the EB has sufficient low end torque and 1st gear is low enough in the 6 speed to make this nowhere near as important as it used to be.

If my suspicions are correct, the truck you are looking at with the 4.10's may not have the HD payload and max tow package. THIS is more important than gear ratio for towing a 9500# trailer. Don't I remember one of your very first threads where you thought you were misled about your towing capacity? This time, let's do it right!

If these trucks are in stock at the dealer, you need to go look at the door jamb sticker for GVWR and payload ratings. Also note that a WD hitch will be required and even with that, max tongue weight is 1130#. If the Jayco has a heavier tongue weight, you should not tow it with a 1/2 ton truck.

 

Mislead yes, but this time around I'm not planning to pull a light fifth wheel and should be absolutely fine with the Jayco trailer as far as payload is concerned. If the current Tundra can pull the Jayco with ease then an fx4 with max tow and ecoboost should be able to handle it. If I was still planning to pull the light fifth wheel, you are absolutely correct.

My Tundra has a 4.30 rearend so that is why I am bringing this up... the Tundra obviously gets **** for gas mileage and the rearend is a big part of that. I am leaning towards the 3.73 setup from Ford but I still want to make sure it's not a huge jump in mileage going to the 4.10s because I can get them both for almost identical money.

 

What are the gears the the tranny on the tundra? Also look at the torque curve for the two engines. I suspect the 5.7L in the tundra needs a lot more revs to get into the power.

I doubt anyone can say with any level of accuracy the difference in mileage you would see. There are just too many variables in the equation. Look at the spread around here on just the EB trucks that are similarly optioned. Now try to apply those numbers to two different trucks with different drivers from different parts of the country. Any one of those items can account for a few MPG difference together it makes a fair comparison impossible.

Try to drive both exactly how you always drive and see the difference. That will be the only way to get a true idea of what it will be.

 

I wish I could drive both, can't find a 4.10 locally much less in the US. They are a rare breed for sure. I'm leaning towards the 3.73's as I have found several trucks already built with the features I want, it will all come down to the money.

 

Just because it "pulls it with ease" doesn't mean you are not over a rating once you put people and cargo in the truck.

 

I can guarantee I'm not overloading the truck as I've weighed it. It's close but definitely not overloaded.

 

X2!!! To the OP, I have a FX4 Eco with 157" wheelbase and max tow pkg. I tow a 32' 9" trailer and it weighs 7500lbs(loaded). With the trailer and truck loaded and ready to go I'm only 180lbs from my trucks GVWR of 7700lbs.. Now your talking about basically the same truck towing a trailer that is 2000lbs heavier.. It will all depend on what you want for options in the truck which will count against your payload and what the exact tongue weight is on the Jayco once it's loaded.. My truck has just about every bell and whistle and my payload is 1700lbs... If you are looking at something with less options you will obviously have a bit more payload to play with..

 

The OP was asking 4.10 vs 3.73 mileage towing and not towing, not payload.

I am well within ratings while pulling both the boat and travel trailer.