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Drive ratio - 4.27 vs. 4.46 on road driving experience difference?

Goat4454

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Can someone explain in simple terms the difference in on-road driving experience for these drive ratios ?
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Higher the ratio, more RPM’s, loss in fuel economy, louder ride. Gain torque at lower speeds, better burnouts and better for bigger tires
 

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Can someone explain in simple terms the difference in on-road driving experience for these drive ratios ?
Look up a gear calculator and put in the ratios for the 10 speed, the transfer case you’re getting, and then the two options for final gearing. You can then look at the RPMs at every speed and gear and compare. There are also lots of threads on it...just don’t compare Jeep or other final ratios to Bronco, that final number is worthless without controlling for transmission and transfer case ratios.
 

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love the info!
 

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With 10 forward speeds, differences will be minimal. If we still had 4 speed autos it would be more significant.
 
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Goat4454

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With 10 forward speeds, differences will be minimal. If we still had 4 speed autos it would be more significant.
Will MPG be significantly different between 4.27 and 4.46 ?
 

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Will MPG be significantly different between 4.27 and 4.46 ?
No. RPM at any given speed will be 5% different, so at highway speeds maybe 100 RPM crawling maybe 50 RPM so no big deal. Just take which ever one Ford offers in your Engine/Transmission/Trim combination, you'll be none the wiser.
 

Whelan007

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No. RPM at any given speed will be 5% different, so at highway speeds maybe 100 RPM crawling maybe 50 RPM so no big deal. Just take which ever one Ford offers in your Engine/Transmission/Trim combination, you'll be none the wiser.

Won't the transmission have different calibration depending on the gear ratio.
Isn't that what happens when you change tire size and get it adjusted.
 

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Won't the transmission have different calibration depending on the gear ratio.
Isn't that what happens when you change tire size and get it adjusted.
Your speedometer is set for Gear Ratio/Tire size and will be set appropriately from the factory. If you change gear ratio/tire size calibration should be reset or just live with the error.
 

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Goat4454

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No. RPM at any given speed will be 5% different, so at highway speeds maybe 100 RPM crawling maybe 50 RPM so no big deal. Just take which ever one Ford offers in your Engine/Transmission/Trim combination, you'll be none the wiser.
Going to know that MPG won’t get worse
 

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No. RPM at any given speed will be 5% different, so at highway speeds maybe 100 RPM crawling maybe 50 RPM so no big deal. Just take which ever one Ford offers in your Engine/Transmission/Trim combination, you'll be none the wiser.
@Goat4454
Qouted above is about as solid of an answer as you are going to get.

Now for my 200 words anyways:
Let Ford build your truck and you'll be alright.

If everything else remained the same, you'd NEVER know the difference between those two gears.
NEVER!
Ford has their engineering dead on in regards to the tranny/gearing/tire combinations.

I used the calculator at http://www.grimmjeeper.com/gears.html and ran all the factory options available.
From a base Base to a Sasquatch and every thing in between, the difference at 70 or 80 mph was not much more than a few RPM's. An absolute non-issue.
 
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Goat4454

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@Goat4454
Qouted above is about as solid of an answer as you are going to get.

Now for my 200 words anyways:
Let Ford build your truck and you'll be alright.

If everything else remained the same, you'd NEVER know the difference between those two gears.
NEVER!
Ford has their engineering dead on in regards to the tranny/gearing/tire combinations.

I used the calculator at http://www.grimmjeeper.com/gears.html and ran all the factory options available.
From a base Base to a Sasquatch and every thing in between, the difference at 70 or 80 mph was not much more than a few RPM's. An absolute non-issue.
Which explains why no difference in MPG between the various final ratios ??
 

Drex

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The driving experience as far as torque multiplication and RPM is affected by the circumference of the tire in addition to the final ratio. With equal sized tires you will get 9.6% more RPM at the same vehicle speed with the 4.46 gears. You also get an extra 9.6% torque applied at the hub of the wheel. It is a mechanical advantage. Like using a longer wrench on a bolt. It twists the bolt harder with the same force on the handle, but the handle moves further. Imagine a 8 inch wrench; you crank on a bolt and it won't budge. So you go get a wrench that is twice as long, now the bolt turns pretty easily. Double the length of the wrench, double the twist (torque) on the bolt. 10% longer wrench moves the free end 10% more (RPM) and twists the center of the wheel 10% harder. That is what your gearing does. With the same size tire, if the 4.27 gearing had you running 2300 RPM at 60 MPH, the 4.46 would be spinning at 2300 * 1.096 or 2521 RPM. 221 RPM higher. At 80MPH would be 3067 and 3361 RPM respectively at 294 RPM more. Not a huge difference, but probably an MPG or two lower.

Part two is wheel circumference. A larger wheel/tire takes less revolutions than a smaller one to be traveling at the same MPH. if one tire is 50 inches around the outside, it will spin twice as many times as a 100 inch circumference one would in the same amount of time at the same speed, that would halve your RPM at the same speed.

Now, here is the key; if you have two gears about 5% different (like the 4.46 to the 4.70) and put a 5% bigger circumference tire on the lower gear (paradoxically the lower gear has the higher number) they effectively cancel the gearing differences. As it happens the Sasquatch tire circumference is just about 5% longer than the Badlands 33" tire. So the Sasquatch tire on the 4.70 gears will have almost exactly the same RPM at the same speed as the 33" tire on the 4.46 gears.

You can look up the circumference of different tires and then subtract the percentage difference from that 9.6% gearing difference to get the actual percent difference and figure out RPM differences from there. It is easy if it is the same tire, 9.6% difference.

Short version; higher numbered gears multiply torque more. More power at the ground for a given MPH. It also raises the RPM at that given MPH.. Tire sizes can change how much different the power at the ground and the RPM. Not really power, but it is close enough.

Edit: fumble fingered my calculator, should be 4.4% difference between the gears, so my distances are just over doubled what they should be, sorry. The theory is correct though.
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