Gear ratio to tire size - sasquatch or not?

[Rubisquatch]

I’m definitely Getting a Badlands and I’m definitely planning on running 35s (or 315s which are actually 34.4s) but I’m still not sure about squatching when I order my Bronco. All I’d get really by squatching is 4.7 gear ratio as opposed to 4.46 non squatch (yes I know I’d get bigger fenders too and maybe 9-10mm of height). I do plan on adding a 2-2.5” suspension lift also so the little extra height is not really a concern.

So I guess I’m asking any gear experts if I really need the 4.7? I had a Rubicon with 35s and 4.10 gearing and it was great on trail and road (well, needed more power but thats due to the FCA 3.6L not the gearing). I’m thinking if I know I’m not going bigger than 35s ever wouldn’t the 4.46 that comes standard be more than fine?

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[kodiakisland]

That chart is for a 1:1 final drive ratio. Great for comparing gears in 80s and earlier vehicles with V8s. Not so much these days.

 

[NCOBX]

I probably wouldn’t get worked up about making the 4.70s a have to have. But I guarantee the difference between the two will be noticeable and make a difference in driving experience. Granted with the 10 speed it will help mask being under geared which will help.

 

[NCOBX]

That chart is for a 1:1 final drive ratio. Great for comparing gears in 80s and earlier vehicles with V8s. Not so much these days.

I wouldn’t get worked up over the actual RPM, the balance between gears and tire size is still valid if you want to keep 9th and 10th gear usable.

 

[kodiakisland]

I probably wouldn’t get worked up about making the 4.70s a have to have. But I guarantee the difference between the two will be noticeable and make a difference in driving experience. Granted with the 10 speed it will help mask being under geared which will help.

Yep, if you pay attention to your vehicle, you will notice. If not, then you won't. If driving an auto, just push the skinny pedal down until you get where you are going. Performance isn't everything.

 

[NCOBX]

Yep, if you pay attention to your vehicle, you will notice. If not, then you won't. If driving an auto, just push the skinny pedal down until you get where you are going. Performance isn't everything.

That’s exactly my problem haha, I pay way too much attention and it works on me.

 

[Rubisquatch]

Good input guys - the reason I’m waffling on squatch is I want the 2.7L. So if it came down to 2.7 Engine and 4.46 Gear OR 2.3 engine and 4.7, which option would be better?

 

[kodiakisland]

So I guess I’m asking any gear experts if I really need the 4.7? I had a Rubicon with 35s and 4.10 gearing and it was great on trail and road (well, needed more power but thats due to the FCA 3.6L not the gearing). I’m thinking if I know I’m not going bigger than 35s ever wouldn’t the 4.46 that comes standard be more than fine?

Can't tell you how many times I've heard this. My vehicles a dog, but the gears are fine.
Well, no, they aren't. You either get things done with raw horsepower, or through the work of gears. Go drive an old Powerwagon with 150hp and you will not describe it as underpowered. Top end will certainly hurt as there is no overdrive, but correct gears give plenty of power.
Same with your Jeep.

Many people just accept poor performance as normal. It doesn't have to be. Lower gears give more performance on the low end, and modern transmissions have high enough final drives to not be a handicap.

If you don't mind describing your vehicle as slow and underpowered, get the higher gears.

 

[Rubisquatch]

Can't tell you how many times I've heard this. My vehicles a dog, but the gears are fine.
Well, no, they aren't. You either get things done with raw horsepower, or through the work of gears. Go drive an old Powerwagon with 150hp and you will not describe it as underpowered. Top end will certainly hurt as there is no overdrive, but correct gears give plenty of power.
Same with your Jeep.

Many people just accept poor performance as normal. It doesn't have to be. Lower gears give more performance on the low end, and modern transmissions have high enough final drives to not be a handicap.

If you don't mind describing your vehicle as slow and underpowered, get the higher gears.

This is great feedback, thank you. I can clarify but the Jeep was not a dog per se. it would have been nicer if it went faster but as a Jeep on 35s, it did 80 -90 on the highway when needed, great around cities but was not as fast as other cars, but it was totaly fine for the most part. Would I have liked it to accelerate faster, sure. Was it an issue, no.

 

[kodiakisland]

Good input guys - the reason I’m waffling on squatch is I want the 2.7L. So if it came down to 2.7 Engine and 4.46 Gear OR 2.3 engine and 4.7, which option would be better?

I assume you are looking at the same transmission on both. I haven't looked at any dyno data on the 2.7, but I would expect it to to like lower RPMs than the 2.3. If that's the case, it should work out about the same. Modern 4cyls like higher RPMs and benefit from lower gears to keep them in the sweet spot.

If you are looking at different transmissions, the auto has lower gears than the manual and can tolerate a higher rearend.

Lots of factors that play into choosing the correct gears for a specific vehicle.

 

[Rubisquatch]

I assume you are looking at the same transmission on both. I haven't looked at any dyno data on the 2.7, but I would expect it to to like lower RPMs than the 2.3. If that's the case, it should work out about the same. Modern 4cyls like higher RPMs and benefit from lower gears to keep them in the sweet spot.

If you are looking at different transmissions, the auto has lower gears than the manual and can tolerate a higher rearend.

Lots of factors that play into choosing the correct gears for a specific vehicle.

Thanks - I’m going wth the auto. i like manual but for this rig, it will be auto.

 

[EvlNvrDys]

@kodiakisland you seem to be well versed in gears and I'm at a loss. I come from FSB's that had 351's under the hood, and after a quick Google search had 3.55 gears in the rear. We all know around 210 hp and I want to say 350 lb ft of torque. Either had 33" AT's or 35" MT's. Always had great acceleration and could tow 5000+ lbs without issue.

Wife's Jeep (2017) I know it sucks.. But has the V6, 33" tires, 3.23 gears? Acceleration OK, but can't tow shit.. Huge dog, talking towing empty 1600lb trailer.

So if I get the 2.7 in my Bronco and will tow 3500 lbs running 33's or 35's would I be OK with the 3.73 gears? Or should I look at the 4.46 or 4.70's? I ask because I may not opt for the Squatch package, but if I can't tow 3500 lbs with what I consider to be enough power I'm gonna be pissed I got the wrong gears in the rear.

Thanks in advance.

 

[NCOBX]

The more gearing you have the happier you will be.

Thanks - I’m going wth the auto. i like manual but for this rig, it will be auto.

I think you will be fine with 4.46 and the auto, it’s not going to be a speed demon by any stretch but 35s aren’t really a massive or heavy tire so you will be fine. You will definitely lose some fuel economy having the 4.46s instead of the 4.70s but I mean it’s an off-road truck so it is what it is.

 

[kodiakisland]

@EvlNvrDys


A lot of the older vehicles we grew up with had V8s that operated at lower RPMs and also had transmissions with 1:1 final drive ratios. Remember when manufacturers made a big deal out of overdrives? I haven't even heard that term used in a long time as all transmission have one, two, or three gears that are "overdrives". Vehicles back then didn't need as low of gears.

If you know you will be towing and plan to run 33s or bigger, I doubt you'll be happy with 3.73s. You should at least look at the 4.46 but would probably be happier with 4.70 if towing with 35s.

 

[NCOBX]

@kodiakisland you seem to be well versed in gears and I'm at a loss. I come from FSB's that had 351's under the hood, and after a quick Google search had 3.55 gears in the rear. We all know around 210 hp and I want to say 350 lb ft of torque. Either had 33" AT's or 35" MT's. Always had great acceleration and could tow 5000+ lbs without issue.

Wife's Jeep (2017) I know it sucks.. But has the V6, 33" tires, 3.23 gears? Acceleration OK, but can't tow shit.. Huge dog, talking towing empty 1600lb trailer.

So if I get the 2.7 in my Bronco and will tow 3500 lbs running 33's or 35's would I be OK with the 3.73 gears? Or should I look at the 4.46 or 4.70's? I ask because I may not opt for the Squatch package, but if I can't tow 3500 lbs with what I consider to be enough power I'm gonna be pissed I got the wrong gears in the rear.

Thanks in advance.

Bronco with 35s and 3.73 will be a dog. Your fuel economy will suffer and your entire driveline will be stressed from being under geared. You will be significantly happier with either gear sets you mention over 3.73s.

I run 4.56 with 37s which feels pretty good, but the case could be made for me to move to 4.88s.

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