Explorer1456
New member
Getting ready to purchase a ‘17 F350 DRW for a future Lance 1172 and need some input on the best gears. Do I really need to go with 4.10’s or would 3.73’s do the job and save me some fuel?
3.73 VS 4.10 gear ratio’s
- Thread starter Explorer1456
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Explorer1456
New member
Definitely going with the Powerstroke Diesel motor, probably staying with stock tires. The camper weighs in around 4500lbs wet. Not really planning on serious offroading, there is only so far a camper hanging that far of the rear wants to go. Not planning on do any towing but let say maybe a small boat/utv trailer.
Don't expect significant savings, if any, by changing gear ratios. The horsepower requirements to move the rig down the road doesn't change based upon changing gear ratio. If your change in ratio drops your RPM's by 500 at highway speed the fuel savings would be the amount required to spin your engine 500 RPM faster.
chet6.7
Explorer
Find out your trans gear ratios and plug them in using both rear diff ratios.What rear diff ratio will allow you to pull a mountain grade in 4th at 55MPH with the engine in its sweet spot.
My Cummins likes around 2K,this also gives me enough RPM to make it easy on the trans and the E-brake works better with some RPM.I think in terms of 55MPH as that is CA's limit with a trailer,and it is the limit on the state hwy's in CA and OR.I would not go down Sexton summit or Siskiyou summit faster than 55 with a load either.Your needs may be different.
http://www.grimmjeeper.com/gears.html
My Cummins likes around 2K,this also gives me enough RPM to make it easy on the trans and the E-brake works better with some RPM.I think in terms of 55MPH as that is CA's limit with a trailer,and it is the limit on the state hwy's in CA and OR.I would not go down Sexton summit or Siskiyou summit faster than 55 with a load either.Your needs may be different.
http://www.grimmjeeper.com/gears.html
Mundo4x4Casa
West slope, N. Ser. Nev.
Explorer,
I have some questions. How old are you? This makes a big difference, usually in how fast you travel. 40 years ago, I would try to stay 5 mph above the posted speed limit. 40 years later, I travel leisurely in the slow lane just downshifting for hills. I recently changed my gears from 3.54:1 to 4.10:1 when I went with 35 inch tires, heavier wheels, carrying my under 2K pound wet Lance Camper to the boonies. For my driving style and the load I'm carrying, I'm in the sweet spot with the 6 speed manual and 4.10's. If you are absolutely sure you will never install taller tires, I'm thinking 4.10's would be ideal with the heavy Lance 1172 even without towing. The International V-8 diesel likes to rev; at least more than my Cummins I-6. With the incredible power now of all the available diesel pickups, you could probably go with either ratio and not see much difference. Do you drive with the pedal down a lot? If you need all the power that the engine produces to stay in the fast lane, go with the 3.73's as the trans will downshift more and deliver more usable power. My bro just bought a used 2015 Ford F-350 SRW Navistar with the twin turbos. Boy, that is some power when the duelin' turbos kick in. You need to know what end of the power need you are on.
jefe
I have some questions. How old are you? This makes a big difference, usually in how fast you travel. 40 years ago, I would try to stay 5 mph above the posted speed limit. 40 years later, I travel leisurely in the slow lane just downshifting for hills. I recently changed my gears from 3.54:1 to 4.10:1 when I went with 35 inch tires, heavier wheels, carrying my under 2K pound wet Lance Camper to the boonies. For my driving style and the load I'm carrying, I'm in the sweet spot with the 6 speed manual and 4.10's. If you are absolutely sure you will never install taller tires, I'm thinking 4.10's would be ideal with the heavy Lance 1172 even without towing. The International V-8 diesel likes to rev; at least more than my Cummins I-6. With the incredible power now of all the available diesel pickups, you could probably go with either ratio and not see much difference. Do you drive with the pedal down a lot? If you need all the power that the engine produces to stay in the fast lane, go with the 3.73's as the trans will downshift more and deliver more usable power. My bro just bought a used 2015 Ford F-350 SRW Navistar with the twin turbos. Boy, that is some power when the duelin' turbos kick in. You need to know what end of the power need you are on.
jefe
Kali
Member
I have a 16 ram 3500 with the 3.73s , it pulled my 17 Lance 1172 just fine. If you plan on upgrading the rims I would consider the4.10. I have upgraded my rims and seems a bit hesitant on take off empty. On a side note, I would look into a Host camper before your Lance purchase. After owning a Lance not a fan. My mammoth will be delivered in January.
Buliwyf
Viking with a Hammer
Either is fine with a 6 speed on the freeway. Only 1st gear is really effected. And I'm really gentle on the truck in 1st gear. (master tech, so I know what happens when you stomp on it)
The 3.73 in 5th gear, is about the same as a 4.56 in 6th gear, and so forth for the 3-6 gears. 4.10 and 4.30 are somewhere in the middle. Stock tires and 3.73 is perfectly fine. In some cases the 3.73 is superior. You'll have more power in 3rd gear with 3.73, than 4th would with 4.10's. Getting going in 1st gear is the biggest difference, and a 6.7L DRW ain't going to have trouble with that.
But if you want beastly tow ratings, get the 4.10. Unless the E-locker is truely available for the 3.73 truck. I didn't think the DRW's could get the OEM E-locker at all.
Here's the #'s from a 3.73 vs 4.30 gasser argument, for example:
2nd is 2.31 3.73= 8.62 4.30=9.933
3rd is 1.51. 3.73=5.63 4.30=6.49
4th is 1.14. 3.73= 4.25 4.30= 4.90
5th is 0.87 3.73=3.24 4.30=3.74
6th is 0.69 3.73=2.57 4.30=2.96
Since a gear lower with the 3.73 is much higher rpm than a gear higher with 4.10, you might find yourself needing to slow down a little bit on hills. No big deal.
The 3.73 in 5th gear, is about the same as a 4.56 in 6th gear, and so forth for the 3-6 gears. 4.10 and 4.30 are somewhere in the middle. Stock tires and 3.73 is perfectly fine. In some cases the 3.73 is superior. You'll have more power in 3rd gear with 3.73, than 4th would with 4.10's. Getting going in 1st gear is the biggest difference, and a 6.7L DRW ain't going to have trouble with that.
But if you want beastly tow ratings, get the 4.10. Unless the E-locker is truely available for the 3.73 truck. I didn't think the DRW's could get the OEM E-locker at all.
Here's the #'s from a 3.73 vs 4.30 gasser argument, for example:
2nd is 2.31 3.73= 8.62 4.30=9.933
3rd is 1.51. 3.73=5.63 4.30=6.49
4th is 1.14. 3.73= 4.25 4.30= 4.90
5th is 0.87 3.73=3.24 4.30=3.74
6th is 0.69 3.73=2.57 4.30=2.96
Since a gear lower with the 3.73 is much higher rpm than a gear higher with 4.10, you might find yourself needing to slow down a little bit on hills. No big deal.
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Kali
Member
zb39, why the truck upgrade?
Darwin
Explorer
You could check out camperlogic.com they have a build thread in the earthroamer etc just above this one. It is aluminum and looks really well thought out and designed to carry a camper on the back. I am not sure if the typical off the shelf aluminum flat bed like CM or Hillsboro could take the weight and twisting having a camper loaded onto them.
I want the ability to customize my storage and bring more toys. I also have a new 8.5 x 20 enclosed trailer I want to haul on some trips. I just like everything to be over built. I go to the Knob Creek
machine gun shoot every year. I want to load my guns and ammo and my Kubota RTV in the trailer. I don't want to be at 16k with a 14k GVW. I will also be flat towing a new wrangler behind on different trips. Also I want to go back to Alaska and go to some places I couldn't when I was in my 40' DP towing a car.