CdnHO
Well-Known Member
For all you guys with the 2019 and newer 3500 with HO and Aisin trans. Trying to decide between the 3.73 (standard) and the 4.10. What is your RPM at 60 MPH. Let me know what ratio you are running. Thanks and stay safe.
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Axle Ratio Decision
- Thread starter CdnHO
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MikeXM
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Here are a few pointers:
3.73: 1530rpm @ 60mph, 1920rpm @ 75mph and 2190rpm @ 85mph.
4.10: 1690rpm @ 60mph, 2120rpm @ 75mph and 2410rpm @ 85mph.
All assuming 30.8in effective diameter tires which sounds about right for the stock tires (31.8in specs).
I went with the 3.73 as I make a lot of unloaded miles. I wanted to save a bit on fuel so it did make sense.
But from what users have reported, it doesn't seems like I saved much. My best unloaded tank so far is 15.4mpg and other have reported similar with the 4.10.
Would I still buy the same? I think I would. Do I feel I could have used the 4.10 for towing instead? Not at all so far. But would the 4.10 be out of question? Nope.
3.73: 1530rpm @ 60mph, 1920rpm @ 75mph and 2190rpm @ 85mph.
4.10: 1690rpm @ 60mph, 2120rpm @ 75mph and 2410rpm @ 85mph.
All assuming 30.8in effective diameter tires which sounds about right for the stock tires (31.8in specs).
I went with the 3.73 as I make a lot of unloaded miles. I wanted to save a bit on fuel so it did make sense.
But from what users have reported, it doesn't seems like I saved much. My best unloaded tank so far is 15.4mpg and other have reported similar with the 4.10.
Would I still buy the same? I think I would. Do I feel I could have used the 4.10 for towing instead? Not at all so far. But would the 4.10 be out of question? Nope.
CdnHO
Well-Known Member
MikeXM, That is exactly the info I was looking for. Most of my miles are towing a 20K+ fifth wheel RV. Since the HO peak torque is at 1800 RPM the 4.10 will get me fairly close to that. I will order the truck with the Max Tow Package with includes the other options I want. Thanks a lot.
I have a 2019 3500 DRW with the H. O. And Aisin with the 4.10’s. At 60 mph I am around 1700 rpm with stock tires. I get about 14-15 mpg unloaded. Never been over 16 mpg yet. 9000 miles so far.
CdnHO
Well-Known Member
boatdude1, how is your fuel mileage pulling heavy? I usually run between 60 and 65 pulling.
Which is pretty much what I showed in your other thread....
hdrams.com
Rear axle ratio recommendation
I pull a fairly heavy fifth wheel RV at around 21,000 pounds. Looking at ordering a 2021 3500 Club Cab dually with the HO and Aisin. This comes standard in 3.73 rear axle. A friend is recommending a 4.10 axle as he is concerned that the Aisin trans might hunt a lot with that weight. My fifth...
hdrams.com
CdnHO
Well-Known Member
Brutal_HO. Totally missed that chart. Sorry man. Would not have posted this thread had I seen it.
I only tow our toy hauler with the truck. It is about 15,000 lbs loaded. I get about 10 mpg at 60 mph.
CdnHO
Well-Known Member
If Tow/Haul locks the transmission into 5th gear, then Brutal_HO's chart might point to 3.73 as a better choice since peak torque is reached around 60 mph. Just want to make the best decision as I will be with this truck for a while.
TH doesn't lock out any gears. The truck will upshift into 6th in TH if conditions are right. You have to use the ERS (Electronic Range select) to lock out 6th or any desired upper gear.
CdnHO
Well-Known Member
OK. Great. 4.10 it is according the guys recommendations as well as your chart. Hard to believe I am going to spend five times for a truck what I paid for my first house. LOL Yeah, I am THAT old.
CdnHO
Well-Known Member
I appreciate everyone's input.
Yea, IMHO, 65 in 6th gear is going to put you right at 1800 if that's what you want. Not sure if that's where everyone is getting the best mileage, but it's the peak torque spot.
Again, lugging 21K I don't think I would want the 3.73 in the dually but it also depends WHERE you tow. I tow in the mountain west and the 3.73 does well for my setup but I'm at just under 16K and also upsized the tires, giving me an effective 3.55 ratio, something you're not likely to do with the dually. Seems to run your 60-65MPH with that weight and 3.73 you'd have to drop a gear and run higher revs.
Again, lugging 21K I don't think I would want the 3.73 in the dually but it also depends WHERE you tow. I tow in the mountain west and the 3.73 does well for my setup but I'm at just under 16K and also upsized the tires, giving me an effective 3.55 ratio, something you're not likely to do with the dually. Seems to run your 60-65MPH with that weight and 3.73 you'd have to drop a gear and run higher revs.
CdnHO
Well-Known Member
Many years ago I was taught in mechanics school that peak torque was the point of maximum efficiency. Of course that is before diesels were big even in the big trucks.
Not a lot of hills between Detroit MI and Brownsville TX. But if I decide to go west, I hear there are some big hills there. LOL
Not a lot of hills between Detroit MI and Brownsville TX. But if I decide to go west, I hear there are some big hills there. LOL
There's always the possibility the wife will want a bigger trailer at some point... If it's your "forever" truck, you have to factor that as well.
CdnHO
Well-Known Member
I sure hope not. She is busy trying to overload this one already. With two ten thousand pound axles, she probably has some room for more junk in this one. 
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Me too.
CdnHO
Well-Known Member
CdnHO
Well-Known Member
These trucks are sure a lot more complicated than my first car. Six banger with three on the tree.