3.55 vs 3.73 diff ratio

[jacknbella]

OK, getting ready to purchase a new tow vehicle but can't decide between a 2010 F150 and a 2010 Ram. Unfortunately, all the models in my price range come with a 3.55 limited slip diff. Let's hear from the experts!!! What should I do?

 

[JB]

Re: 3.55 vs 3.73 diff ratio

What does you tow weigh?

What are the tow ratings of the F150 with the 3.55 and with a 3.73?

 

[his1911]

Re: 3.55 vs 3.73 diff ratio

ONe other aspect to consider between 3.55 and 3.73's is how much you tow vs how often you drive the tow rig without actually towing. The difference in gearing can make a big difference in fuel economy.
Nathan

 

[shorts&chanclas]

Re: 3.55 vs 3.73 diff ratio

I would find a way to take the 3.73. Maybe wait a little bit longer to save up for it? I'm sure its pricy'er because you have to buy some stupid accessory package to get the 3.73. You might save up to 1/2 mpg with the 3.55 but I think it will be something of a dog in some situations.

 

[DJ]

Re: 3.55 vs 3.73 diff ratio

Compare tire size also.

 

[windsors03cobra]

Re: 3.55 vs 3.73 diff ratio

Re: Tow capacity and fuel mileage, the difference between those 2 ratios will be negligible at best.
Limited slip, Yes ! Dont forget 4wd and both are great trucks.
Avoid 20 inch wheel equipped models unless you love ridiculously priced tires.

 

[642mx]

Re: 3.55 vs 3.73 diff ratio

ONe other aspect to consider between 3.55 and 3.73's is how much you tow vs how often you drive the tow rig without actually towing. The difference in gearing can make a big difference in fuel economy.
Nathan

Thats true to a point, but I have 4.30's in my Tundra and I can get 17+ mpg (which better than the Ford and Dodge).

To the OP... if your buying a Ford, get the 3.73.... cause that low output 5.4 is going to need all the help it can get.

 

[jfadool]

Re: 3.55 vs 3.73 diff ratio

Thats true to a point, but I have 4.30's in my Tundra and I can get 17+ mpg (which better than the Ford and Dodge).

To the OP... if your buying a Ford, get the 3.73.... cause that low output 5.4 is going to need all the help it can get.

Not true, the ford out tows and hauls the Tundra, and gets better mileage.

http://www.fueleconomy.gov/

 

[jacknbella]

Re: 3.55 vs 3.73 diff ratio

I tow our 5500 lb rig about twice a month, 1.5 hrs each way, 6 months in our boating season, and mostly flat terrain. I am definitely getting a 4x4 because no one here in the midwest bothers with 2WD due to harsh winters. The truck will also serve as my daily commute vehicle (15 miles each way).

I am leaning to a Ram 1500 right now due to its 390 hp HEMI but it also comes with a 3.55, unless I go up on price

I've heard the Ford 5.4L is a pooch but I like the overall appeal and styling of it compared to the Dodge. It's also a bit cheaper. However, some of the newer Ram's have those "Ram Boxes" which could be the selling point because I like the idea of having a trunk in a truck (that could be a country song...).

Thanks for everyone's input! Keep it coming though!!!

 

[642mx]

Re: 3.55 vs 3.73 diff ratio

Not true, the ford out tows and hauls the Tundra, and gets better mileage.

http://www.fueleconomy.gov/

Lets forget about the google searches for a minute... The Ford is something like 60 horse shy of the Tundra and Ram. How could it be a better puller when its so low on power?...

And the MPG thing is from real world experience. One, I use to work for Ford... Two, My Dad has a 5.4L powered F-150. So I can say from real world experience, the Ford is not only a pig, but with a 14 mpg average, its a thirsty pig.

 

[JaseBosto]

Re: 3.55 vs 3.73 diff ratio

Lets forget about the google searches for a minute... The Ford is something like 60 horse shy of the Tundra and Ram. How could it be a better puller when its so low on power?...

And the MPG thing is from real world experience. One, I use to work for Ford... Two, My Dad has a 5.4L powered F-150. So I can say from real world experience, the Ford is not only a pig, but with a 14 mpg average, its a thirsty pig.

Horsepower is actually the last thing I think about when purchasing. I want to know something about the transmission, braking, and how much the rig weighs. If horsepower were all that mattered, then everyone would tow with compact cars. ANY truck will pull your boat down the road. A good truck will be able to stop it, and not get thrown around on the highway while towing it. Both those trucks will do it fine so, I would pick based on personal preferance, which would be the Ford anyday over the dodge(I drive a chevy).

I pull my boat with a 2wd, V6, Automatic regular cab Silverado with 3.42:1 gearing and a rear locker.... I haven't had any problems towing, or stopping, or pulling my boat up the STEEPEST ramps around here. Loaded up I am probably shaking hands with 3000lbs or more based on the boats dry weight.

 

[Silvertip]

Re: 3.55 vs 3.73 diff ratio

Gas mileage and towing discussions are a hoot to watch. Rarely do people consider what they are towing, where they are towing, how fast they are towing, what they are towing with, how they are towing and most importantly, "who" is driving. Put two people in identical vehicles (towing or not) and you will get very different results. Next, it isn't horsepower alone that makes a good tow vehicle. It helps obviously but it is torque and where in the rpm band that horsepower and torque are developed. In my view it doesn't make sense to buy any tow vehicle these days with a 3.55:1 axle(s) when most of them have these giant tires on them. It will certainly provide a tad better mileage with nothing in tow but you could end up with much worse mileage when towing because it takes a great deal of power to overcome a poor axle selection. The proof in this is to install a vacuum gauge and do the testing. You will generally find that the lower the vacuum reading becomes (low numerical axle ratio), the poorer mileage will be and that will almost always happen when comparing a 3.55 to a 3.73 in towing applications. The opposite will likely be true when not towing. Since others have expressed their "real life" towing experience I'll relate just one of mine except it is not a Tundra/Ford/Dodge comparison but rather a Honda Ridgeline and an S10 Crew Cab. 450 mile round trip each towing nearly identical walleye boats. First stop for gas the Honda owner asks what could be wrong with his vehicle because he was having trouble keeping up and it was shifting all the time. Answer? Busy transmission. Excessively high revs burns fuel. The Honda has a distinct HP advantage (250 vs 190) and torque was about the same 247 vs 250). However, the Honda torque came at 4300 RPM and the S10 delivers 90% of starting below 2000 rpm. I tow that boat in OD and it rarely needs to leave that gear. The S10 had 3.73 gears. Mileage comparison was 17 on my truck and 14 on the Honda. I don't know what the Honda was running for RPM by my S10 was around 2000 RPM. There is no doubt the Honda would get better mileage than the S10 when not towing so the lesson here is buy what you want -- not what someone else tells you that you need. You are about to spend a ton of money so research, research, research. All of the details above need to be considered -- not just axle ratio and horsepower.

 

[TilliamWe]

Re: 3.55 vs 3.73 diff ratio

Check out the latest Trailer Boats Magazine for a test of the F-150, Ram 1500, and Tundra. Non-towing mileage for the Tundra was 13.3, the Ram 11.0, and the Ford (with the 3.73) was 14.4. Towing mileage for the Tundra was 9.7, Ram was 8.2, and the Ford was 7.5. Towed load was a 6000lb Mako center console.
With the Ford, you could get away with the 3.55, if you are getting the 6 speed auto, in my opinion. The Ram had the 3.92 axle ratio and a 5sp auto. A 3.55 with it would not be a good fit, in my opinion.

Braking results for unladen were 55-0mph in 107 feet for the Ford (Ram did better at 104, Tundra did it in 119)
Laden braking 55-0mph Ford needed 196 (Ram 179, Tundra 180)
The Ford weighed 5624lbs in Super Crew 4x4 setup. Its tow rating was 11,200lbs with the 3.73, AND the "Maximum Tow Package", which was a $300 option. No idea what all it included.
RAM was Crew Cab Laramie trim and it weighed 5497lbs. Its tow rating was 9800lbs. It also had the highest sticker price at $49,390 (compared to $43895 Ford, and $45,236 Tundra. But you could control some of that with what trim package/other options you choose, I am sure.

 

[22E6441]

Re: 3.55 vs 3.73 diff ratio

ANY truck will pull your boat down the road. A good truck will be able to stop it, and not get thrown around on the highway while towing it.

True statement!

 

[skargo]

Re: 3.55 vs 3.73 diff ratio

I have 3.55's in my Dodge, but it has 550hp/1100 ft/lbs of torque(at the rear wheels), which makes it perfect. I get 18mpg plus too.

 

[redone4x4]

Re: 3.55 vs 3.73 diff ratio

my 04 dodge has 3.92 in it and i wish it had the 4.56 gears. i definitely would not get anything with the 3.55s in it. I had a ram once with them, it barely got out of its own way especially with the boat. you would be disappointed.

 

[skargo]

Re: 3.55 vs 3.73 diff ratio

my 04 dodge has 3.92 in it and i wish it had the 4.56 gears. i definitely would not get anything with the 3.55s in it. I had a ram once with them, it barely got out of its own way especially with the boat. you would be disappointed.

Must be a gas engine, with a diesel, 3.55's or 3.73's are suitable for 95% of the diesel trucks out there. If you are hooked to a big trailer 24/7, and in the mountains, 4:10s are the way to go.

 

[grahamh]

Re: 3.55 vs 3.73 diff ratio

I'd want the limited slip, even if the ratio is not quite what you wanted.

 

[his1911]

Re: 3.55 vs 3.73 diff ratio

Must be a gas engine, with a diesel, 3.55's or 3.73's are suitable for 95% of the diesel trucks out there. If you are hooked to a big trailer 24/7, and in the mountains, 4:10s are the way to go.

I totally agree I have 3 Ford all 7.3 Ls all close to the same truck the 3.55/5spd manual will get 21-22mpg, the 3.73/4spd auto gets 14-15 and the 4.11/auto got 10-11 those are all unladen mileages, and pretty much any boat up to about 26's is unladen in my opinion but then again I'm used to loads that average 9-10,000 pounds so boats aren't real heavy.

Tire size does make a big difference in the gear ratios also, of course the best pulling truck I've ever owned ( unless you wanted speed) was a 77 Dodge PW-100 225ci with a L,2,3 A-833 manual trans and 4.10's it almost seemed like it'd climb a vetical wall just don't plan on doing more than 40mph unless going down steep hills !!!

 

[redone4x4]

Re: 3.55 vs 3.73 diff ratio

Must be a gas engine, with a diesel, 3.55's or 3.73's are suitable for 95% of the diesel trucks out there. If you are hooked to a big trailer 24/7, and in the mountains, 4:10s are the way to go.

Isnt the original post regarding gasoline engines??? Thats the only reason i posted it. Yes, a diesel is different especially if its a manual trans.