3.73 vs 4.30 axle ratio w 7.3L F350

[abqbw]

I have a weak understanding of axle ratios. Maybe you all can help me out. My special order that is being worked on (F350 Tremor Lariat Ultimate w/7.3L) includes the 4.30 axle. I believe this is optional to the standard 3.73. I wonder if I would be better off with the 3.73 axle?

I do not tow much weight or tow very often. Just a small utility trailer with an ATV once in awhile.

I am getting an F-350 to better carry my relatively light weight Four Wheel Campers Hawk pop-up slide in camper. Would I possibly get a little better gas mileage with the 3.73 or are there other pros-cons to the 3.73 or 4.30?

 

[JC_Tremor]

Here's something that may help you out some. Take with a grain of salt as Tremor has pretty large tires and will be different from what is stated there. It's just to give you an idea, and clear up questions.

Rear Axle Differential Ratio Comparisons for Gas MPG

A vehicle's rear axle ratio is numerically expressed. A higher number denotes a lower ratio. For example, if the axle ratios were listed as 3.31:1 and 3.42:1 and 3.55:1 and 4.10:1, the lowest ratio of the four gears is 4.10:1. The lower the gear ratio, the more rpm required to maintain a given...

itstillruns.com

 

[2020Tremor]

I have a weak understanding of axle ratios. Maybe you all can help me out. My special order that is being worked on (F350 Tremor Lariat Ultimate w/7.3L) includes the 4.30 axle. I believe this is optional to the standard 3.73. I wonder if I would be better off with the 3.73 axle?

I do not tow much weight or tow very often. Just a small utility trailer with an ATV once in awhile.

I am getting an F-350 to better carry my relatively light weight Four Wheel Campers Hawk pop-up slide in camper. Would I possibly get a little better gas mileage with the 3.73 or are there other pros-cons to the 3.73 or 4.30?

I don’t think you can get 3.73 factory installed on a Tremor. With the larger tires on the Tremor higher gears will most likely not give you enough improvement to justify the cost of having the gearing changed. The 4:30s will give you a better crawl ratio when off-roading.

 

[PapaRaptor]

I don't think your mileage will be that different.
stay with the 4:30s
If you get larger tires someday or even wider ones you will be glad.

 

[abqbw]

Here's something that may help you out some. Take with a grain of salt as Tremor has pretty large tires and will be different from what is stated there. It's just to give you an idea, and clear up questions.

Rear Axle Differential Ratio Comparisons for Gas MPG

A vehicle's rear axle ratio is numerically expressed. A higher number denotes a lower ratio. For example, if the axle ratios were listed as 3.31:1 and 3.42:1 and 3.55:1 and 4.10:1, the lowest ratio of the four gears is 4.10:1. The lower the gear ratio, the more rpm required to maintain a given...

itstillruns.com

Thank you. That is a very helpful write up. My camper pushes a lot of wind. I think I’ll go with the 4.30. Besides, I just heard that ford is short on the parts for the 3.73...

 

[abqbw]

I don't think your mileage will be that different.
stay with the 4:30s
If you get larger tires someday or even wider ones you will be glad.

Thank you. Good advice.

 

[JC_Tremor]

Thank you. That is a very helpful write up. My camper pushes a lot of wind. I think I’ll go with the 4.30. Besides, I just heard that ford is short on the parts for the 3.73...

I guess that settles it...

 

[abqbw]

The Ford Tremor forum saves me from myself. Again! What a great forum. So helpful as I put together a special order for a Tremor. Thank you all.

 

[Greggg2018]

The Ford Tremor forum saves me from myself. Again! What a great forum. So helpful as I put together a special order for a Tremor. Thank you all.

 

[Greggg2018]

3.73 is not available on the Tremor, 4.30 only. Already tried. If you want better gas mileage stick with the F350, FX4, 3.55 gearing, not so aggressive tires and larger air dam. Probably 3 mpg better than Tremor package.

 

[PapaRaptor]

Thank you. Good advice.

I got 4:11s in my Jeep, was a bit on the low side but I lifted it 4" and went 3" taller tires and now its prefect. Best part I have factory gears.