Quick question about gearing?
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From: Long Island USA
Depends on the load.
If you're a 90% lightweight (like ME!) the 3.73's will certainly help get the most MPGs on the highway - it'll probably hurt stop-ang-go.
4.30's if you're towing near the load limits with stock tires, and even lower (higher numerically) if you are going oversize tires, run 100% at full-load, or are doing stop-and-go deliveries with a decent load.
What do you intend to do with your truck, and what size tires are you currently (and future-wise) running?
If you're a 90% lightweight (like ME!) the 3.73's will certainly help get the most MPGs on the highway - it'll probably hurt stop-ang-go.
4.30's if you're towing near the load limits with stock tires, and even lower (higher numerically) if you are going oversize tires, run 100% at full-load, or are doing stop-and-go deliveries with a decent load.
What do you intend to do with your truck, and what size tires are you currently (and future-wise) running?
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Fleet Mechanic
Joined: Feb 2004
Posts: 1,902
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From: Northern IL
heres the thing guys, dont want to change gearing I just want to understand it better.
Sorry for the mix up. With my truck I dont tow anything I really use it for when I go out southwest for vacations. I have 265/70/17LT BFG tires and 4:10 gearing this is on my 2005 SD V10 4x4 supercab short box.
Sometimes I here guys talking about how great 4:10 gears are and wanted to know why?
Thanks ~Gage~
Sorry for the mix up. With my truck I dont tow anything I really use it for when I go out southwest for vacations. I have 265/70/17LT BFG tires and 4:10 gearing this is on my 2005 SD V10 4x4 supercab short box.
Sometimes I here guys talking about how great 4:10 gears are and wanted to know why?
Thanks ~Gage~
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Joined: Jul 2002
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From: Long Island USA
The "more" gear (lower gearing, higher numerically) the more the torque multiplication.
Torque goes into the rear, torque comes out multiplied by the number.
My 3.73's multiply the torque from the tranny (which multiplies (or divides) the torque from the engine).
Say I'm in a first gear that has a 3:1 ratio. The engine is putting out a peak of 425ft/lbs.
425*3=1275
1275*3.73=4755.73
4755.73 ft/lbs at the rear wheels, being applied to the ground. If the tires are 32 inches tall, the radius is 16 inches, there is 4755.73*12/16=3566.8 pounds of thrust.
Assuming no friction - there is a decent amount of loss involved.
In overdrive, which is usually around .7:1, at peak torque of 425ft/lbs, you'd see an actual torque at the rear wheels of 1109.675ft/lbs or with 32" tires, a pulling power of 832 lbs.
If the entire truck weighs 6800lbs like mine, you'd have 832/6800=.122 G's of acceleration.
Again, given no aero drag, no friction.
If you increase the rear gearing, going from 3.73's to 4.30's, the amount of G's increases to .14G's
Theoretically.
Torque goes into the rear, torque comes out multiplied by the number.
My 3.73's multiply the torque from the tranny (which multiplies (or divides) the torque from the engine).
Say I'm in a first gear that has a 3:1 ratio. The engine is putting out a peak of 425ft/lbs.
425*3=1275
1275*3.73=4755.73
4755.73 ft/lbs at the rear wheels, being applied to the ground. If the tires are 32 inches tall, the radius is 16 inches, there is 4755.73*12/16=3566.8 pounds of thrust.
Assuming no friction - there is a decent amount of loss involved.
In overdrive, which is usually around .7:1, at peak torque of 425ft/lbs, you'd see an actual torque at the rear wheels of 1109.675ft/lbs or with 32" tires, a pulling power of 832 lbs.
If the entire truck weighs 6800lbs like mine, you'd have 832/6800=.122 G's of acceleration.
Again, given no aero drag, no friction.
If you increase the rear gearing, going from 3.73's to 4.30's, the amount of G's increases to .14G's
Theoretically.
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Neither. Go figure.
Anyway, something to add to the above.
At times, you CAN put more torque-to-the-ground with a V10 than with a stock 6.0 diesel. I proved it somewhere, but don't have the link to the thread anymore.
If you have 4.30's in the V10, are in a lower gear than the diesel (higher RPMs possible because it's a gasser), the diesel has 3.73's, you can actually scream uphill right past a diesel pulling the same load.
In a very limited situation, granted, but it's definitely possible on paper, and we've heard about it here in real life
Anyway, something to add to the above.
At times, you CAN put more torque-to-the-ground with a V10 than with a stock 6.0 diesel. I proved it somewhere, but don't have the link to the thread anymore.
If you have 4.30's in the V10, are in a lower gear than the diesel (higher RPMs possible because it's a gasser), the diesel has 3.73's, you can actually scream uphill right past a diesel pulling the same load.
In a very limited situation, granted, but it's definitely possible on paper, and we've heard about it here in real life
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