gear axle ratio question

Depends......mainly on how you folks drive, where you drive, what you tow....etc

Diff ratios are about 10% apart and "at the same road speed...you will gain about 10% more power

If you go lower (higher numeric) you will gain that much more power going higher numeric....lose about 10% going higher (lower numeric)...

BUT...you might lose MPG when not towing...using it as a CAR...some times...while towing heavy...you might gain a bit more MPG...as the engine won't be working as hard

Also, depends on whether your engine has enough RPMs before red line is required to take advantage of this

noonenosthis1 wrote:
We are still talking about changing them. My husband says that since the new fuel pump is in, she has a little more pep!

I`m sure that's just all in your mind. everyone always feels like that after dome type of repair.

I went from 3.73 to 4.30 towing a similar weight trailer. it is a night and day difference. the 3.73`s are good for up to about 7k lbs. anything more will require 4.30`s. in reality I kind of wish I had gone to 4.56 gears. 4.30 are good, but 4.56`s would be a perfect match for heavier trailers with a tall front wall. Its nice to be able to tow in O/D even in a modest headwind. with the 3.73`s I could never run in O/D. the engine was always in the wrong power band when in 3rd, at 65 the engine was lugging if it went into O/D. I either had to be at 60mph or at 75 to get the engine to perform properly. I can tow in O/D at 67mph at 2300 rpm. yes 300 rpm makes a huge difference!

My trailer is 7100lbs empty and 9200lb loaded for a trip. the gears were worth every penny and your towing mileage will go up. mine went up by .5 mpg. another good towing performance option is a tune from 5 star tuning. they change the shift points that make towing much easier on the engine and trans. and it make approx. 15 more HP which is a nice side effect.

We are still talking about changing them. My husband says that since the new fuel pump is in, she has a little more pep!

Our 2004 X has 3.73 and our last TT was at least that heavy. 33 ft with 2 slides. I agree with Old Bisket, leave it like it is. When you get to a steep hill it will shift down.

Changing gears will help reduce down shifting and the feeling that you are often in the wrong transmission gear.
Are you towing in top overdrive? What rpm cruising the flats?

I would go 4.30 minimum if spending money.

The common belief among EX owners is the 4.30 provides the best all around option. I am shortly going to find out how much better they are than the 3.73's!!

I considered 4.56 by having the gears changed. Est cost in the PNW was $2700!! Would have been the same for 4.30 gear change. I found a pair of used 4.30 axles for $1100 and had my son's Ford dealership go through them, check gears, brngs, do necc seals. Done at $1900. Going to do brakes also before installing the axles.

We are towing an equivalent trailer and have have no problems with the EX. Been up and down 9000 ft passes at not much slower than everyone else around us. But looking forward to how the "towing experience" will change with the 4.30's.

Of course, "Old Bisquick" knows better how the Excursion tows!!!

Right where you are .....3:73