Final drive ratio - 4.46 or 4.7 better for this build?

[KJR50]

With the latest round of info released, 4.7 is confirmed not a no cost option.

In this scenario:
-2.7 with Auto-10spd
-35 someday, but 33 works for now
-daily, mostly highway driving, >75%
-fuel eco/range > power/accel
-most likely no rock crawling, definitely some off roading

Which ratio works better, 4.46 or 4.7? Engine will rev less with 4.46 running 35, what are the drawbacks?

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[KJR50]

Whoa did someone just edit the op

 

[dwbronco]

With the latest round of info released, 4.7 is confirmed not a no cost option.

In this scenario:
-2.7 with Auto-10spd
-35 someday, but 33 works for now
-daily, mostly highway driving, >75%
-fuel eco/range > power/accel
-most likely no rock crawling, definitely some off roading

Which ratio works better, 4.46 or 4.7? Engine will rev less with 4.46 running 35, what are the drawbacks?

I'm kinda curious about this, too.

 

[Mattwings]

Who verified it’s a no cost option? I saw it on the order sheet and it’s only available on the SQ. Dealer is verifying, but so far, no dice.

 

[shoelessjoe]

Who verified it’s a no cost option? I saw it on the order sheet and it’s only available on the SQ. Dealer is verifying, but so far, no dice.

I know B&P isn't the Bible but you can switch to the 4.7 and there is no upcharge. We shall see.

 

[kodiakisland]

This should be more accurate than the B&P, but everything from Ford is suspect at this point:

 

[Drex]

4.7 would give about 5% more mechanical advantage at the cost of about 5% more RPM at the same speed, stock BL tire is about 5% less circumference that SQSH tire, so RPM world be roughly the same with 4.46 33 and 4.7 35. If you get a real 35 in the future, will slightly lower the mechanical advantage and RPM from stock. The heavier weight in the 35s of whatever flavor will increase the braking distance (gearing won't make a difference), slow acceleration, and decrease MPG one to two MPG at a guess. If you think you will fit taller tires in the future, get the 4.7 gears, will help turn the bigger tires. The MPG hit would likely be very small on the gears, but much larger with the taller tires, regardless of the year ratio you choose. (First I heard the the B&P being right over the order guide though, you sure about that?)

 

[Mattwings]

I know B&P isn't the Bible but you can switch to the 4.7 and there is no upcharge. We shall see.

I asked and the dealer is asking as well, but from the order guide (while I was at the dealer) it is pretty specific as SQ only. It will be the factor that sends me to 2.7 vs. 2.3. I think the 2.3 would be very good with the 4.70 gears (probably without too, but....). If I hear something today I will update the post. I was hoping updated information was verified ordering of then option ?

 

[Lilj4425]

4.7 is a higher number so it is clearly the better option.

 

[shoelessjoe]

4.7 is a higher number so it is clearly the better option.

for bigger wheels and tires and off-roading not for gas mileage

 

[PaBronco]

The Rubicons have a 4:10 gear. Guys that run 35s with the 4:10 say it is just right, the off road die hards go with a lower gear (higher number).
Seems like a 4.46 gear would be plenty for most.

 

[kodiakisland]

The Rubicons have a 4:10 gear. Guys that run 35s with the 4:10 say it is just right, the off road die hards go with a lower gear (higher number).
Seems like a 4.46 gear would be plenty for most.

Cool, of course that only matters if the Rubicons have the same transmission, transfer case, engine, etc. as the Bronco. Do they?

 

[KJR50]

@kodiakisland post above, 4.7 listed available as SAS package only.

 

[Spooled]

4.46

 

[CarbonSteel]

The Rubicons have a 4:10 gear. Guys that run 35s with the 4:10 say it is just right, the off road die hards go with a lower gear (higher number).
Seems like a 4.46 gear would be plenty for most.

I would disagree with that. 4.10s "work" with 35" tires, but are not optimum--the 8 speed auto in the Wrangler compensates for the 4.10 against the 35" tires.

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