Difference between 4.30 & 3.55 gears

lawnspecialties wrote:


May I inquire what you're pulling?

Yes you may:

2014 Bighorn 15800#

and

2016 Palomino T/C with loaded weight of 3950# (which includes tongue weight of 10' utility trailer and Super Truss Hitch system)

Hope this answers your questions.

Also, to all who have responded, many thanks. I was told by Ford salesman that the higher the number on rear end gears, the better the fuel mileage. I tend NOT to believe everything I am told, thus the question for those with actual over the highway experience.

Lakeside

275/65r 20 are approximately 34.1 inch diameter.

lakeside013104 wrote:
My 2011 F-350 has a 3.55 geared rear end. The new 2017 F-450 only comes with a 4.30 geared rear end.

Basically the same engine (6.7 turbo diesel).

Does that mean better or worse fuel consumption (towing comparable weights)?

Does that mean that the rpms will run higher with the 4.30 versus the 3.55 assuming one drives at the same highway speeds 62 - 65 mph?

Just wondering.....:@

Lakeside

i can tell you this. i have 73 power wagon. i put a 383 bored .030 over. she rolls on 38 inch tires. ugly as sin. short bed that has been modified to accept a club cab.
when i went from the mid 3.00's to 4.50 my highway speed suked. but in the mud and at moab.........yea baby. i can relocate some terra firma. and the lower gear with them bia ply road hawgs and i can pretty much in low gear climb what ever i want. yea i have limits since i never put fuel injection on it. but non the less that is my feed for ya from personal experience.

lakeside013104 wrote:

lawnspecialties wrote:


May I inquire what you're pulling?

Yes you may:

2014 Bighorn 15800#

and

2016 Palomino T/C with loaded weight of 3950# (which includes tongue weight of 10' utility trailer and Super Truss Hitch system)

Hope this answers your questions.

Also, to all who have responded, many thanks. I was told by Ford salesman that the higher the number on rear end gears, the better the fuel mileage. I tend NOT to believe everything I am told, thus the question for those with actual over the highway experience.

Lakeside

Why are you considering an F450? In my mind the F250; F350 and f450 are all basically the same truck. The f250 should be discontinued as it has nothing to offer. The f450 has 4.30 gears because it is designed for towing 25000 to 32000 lbs. The truck designed for your trailer is the F350. I take it you want dual wheels? According to Fords build and price on their website, the gear ratios available in the dually are 3.55 and 4.10. unless your towing extremely heavy or spending much time off road the 3.55 gears will be better suited and give better fuel economy especially when not loaded.

SoCalDesertRider wrote:
Most of the factory stock tire sizes for American 3/4-ton and 1-ton pickups are within about 2 inches diameter of each other, regardless of the factory wheel size.

When you take the pi factor into consideration, a 2 inch difference in diameter is about a 6.4 inch difference in circumference.....and that's quite a bit.

lakeside013104 wrote:
I was told by Ford salesman that the higher the number on rear end gears, the better the fuel mileage.

But everybody knows that car salespersons are experts on EVERYTHING.
:R

I saw about 1.5 mpg loss.

I went from a 2011 f250 with 20" wheel and 3:55 gears I was averaging about 17mpg empty at 75 mph. My current 2016 f350 drw with 4:30 gears an 17" wheels is getting about 15.4 mpg empty at 67mph.

Did I need 4:30 gears to tow 16k lbs, maybe not, but there has only been one grade that has made this truck drop a gear on the highway. To me its worth it!

The bigger tire dia of the 19.5" that the 450 comes with should help bring the rpm down a tad.

4x4ord wrote:

lakeside013104 wrote:

lawnspecialties wrote:


May I inquire what you're pulling?

Yes you may:

2014 Bighorn 15800#

and

2016 Palomino T/C with loaded weight of 3950# (which includes tongue weight of 10' utility trailer and Super Truss Hitch system)

Hope this answers your questions.

Also, to all who have responded, many thanks. I was told by Ford salesman that the higher the number on rear end gears, the better the fuel mileage. I tend NOT to believe everything I am told, thus the question for those with actual over the highway experience.

Lakeside

Why are you considering an F450? In my mind the F250; F350 and f450 are all basically the same truck. The f250 should be discontinued as it has nothing to offer. The f450 has 4.30 gears because it is designed for towing 25000 to 32000 lbs. The truck designed for your trailer is the F350. I take it you want dual wheels? According to Fords build and price on their website, the gear ratios available in the dually are 3.55 and 4.10. unless your towing extremely heavy or spending much time off road the 3.55 gears will be better suited and give better fuel economy especially when not loaded.

To answer your question, Why F-450, I have always been guilty of, "If big is good, bigger is better".

So maybe the F-350 is the better choice here. Thanks for your input.

Lakeside

Sam Spade wrote:

lakeside013104 wrote:
I was told by Ford salesman that the higher the number on rear end gears, the better the fuel mileage.

But everybody knows that car salespersons are experts on EVERYTHING.
:R

Yep....for sure......salesman speak with forked tongue from time to time.....;)

Lakeside

1jeep wrote:
I saw about 1.5 mpg loss.

I went from a 2011 f250 with 20" wheel and 3:55 gears I was averaging about 17mpg empty at 75 mph. My current 2016 f350 drw with 4:30 gears an 17" wheels is getting about 15.4 mpg empty at 67mph.

Did I need 4:30 gears to tow 16k lbs, maybe not, but there has only been one grade that has made this truck drop a gear on the highway. To me its worth it!

The bigger tire dia of the 19.5" that the 450 comes with should help bring the rpm down a tad.

Exactly the info I was looking for. Thanks for sharing.

Lakeside