
If you’re struggling to figure out which gear reduction you need on your UTV, you’re not alone. People ask us this question all the time. Gear reductions can be pretty confusing, and people are afraid of making the wrong decision—especially when that decision involves dropping a few hundred or a few thousand dollars on parts and labor.
So what gear reduction do you need?
We’ll answer that question for you (or at least narrow down the options) to make your choice as simple as possible.
There a four questions you need to ask yourself before you get started. Prep yourself by answering all four of these:
The single most important question is the first one: where are you riding? We’re going to focus on whether you’re riding on trails, sand, mud, rocks, or roads first and foremost.
So let’s get started.
Most people’s goal with mud is to get the biggest tires and the most torque possible. So at some point, the gear reduction you need is only limited by your budget. For the ideal mud machine, here’s what you need:
Torque is so important for mudding, so don’t skimp on it for your mud machine. Mud tires are big, heavy, and grippy, and plowing through mud takes tons of power. That’s why we recommend going as big as you can.
When it comes to road-riding, you should avoid it with a mudding-focused UTV. The best mud machine is the worst road machine—you won’t be able to get to safe speeds, and if you try, your engine will hit some wild RPMs and stay there the whole time you’re on the road. Stick it on a trailer instead.

Rock crawling demands a more nuanced approach to your gear reduction strategy. It’s not always a situation of “go big or go home.” Instead, you need to think about what setup you really want and how you plan on riding.
It all comes down to your tire size.
Most people think the tire-size sweet spot for rock crawling is about 35”. If that’s your tire size, here’s what we recommend:
OR
AND
We don’t necessarily recommend you combine portals and a transmission gear reduction for rock crawling—adding two gear reductions tends to be overkill. Rock-crawling tires aren’t heavy enough for that.
Plus, gearing down can make road-riding a pain. That’s because gear reductions give you more torque at the expense of your top speed, so if you want to go faster, you have to rev higher—not fun for you or your engine.

Trail riding’s easier. We recommend sticking to the bottom end of the gear reduction range for any standard trail-riding tire size. You’ll feel the extra bottom-end torque every time you roll over an obstacle or climb a hill, but it won’t slow you down when you put the gas down either.
Plus, road-riding (if you need to and are legally allowed to) will be easier with a smaller gear reduction.
If you’re going with a transmission gear reduction, get a 10% or 13% gear reduction.
If you’re going with GDP Portals, go with a 15% gear reduction available on 4” portals.
It’s just enough to give you a little extra oomph every time you hit the gas.
Honestly, you probably don’t want a gear reduction for riding a UTV in sand.
Why?
Gear reductions slow you down and give you torque. Dunes are all about going flat-out (within reason) and hitting top speed. Most stock machines already have enough torque for the task. In fact, you might even consider a high-gear set to give up some of that torque for even more speed.
If you have some torque-related issues like paddle tires that are especially heavy or sand that’s especially hard to turn tires in or something, you might consider a 10% gear reduction.
But if you don’t have a good reason to get one, don’t bother.

So choosing your gear reduction isn’t that tough. Almost everybody can benefit from one. And with multiple ways to get a gear reduction on your side-by-side, it’s never been easier to get more power to the ground.
Get yourself a GDP Portal Gear Lift, a transmission gear reduction, or both, and feel what awesome torque does for you.
21 Comments
Looking to enhance the look and performance of my 2023 Can am outlander xmr 1000
Have decided to go with a portal lift but not sure if I should go 4inch or 6inch portal lift
Currently running the stock 30″ tires but would look to eventually go 32″
Looking for input on tire size and gearing for trail riding and mud
Hi Shawn—this sounds like an awesome project! If you’re more mud than trail, I’d recommend the 6″ GDP lift with 30% gear reduction. That’s going to be the more versatile option.
If you’re more trail than mud, go for the 4″ GDP lift with 15% reduction. You’ll notice the improved torque, but won’t totally sacrifice top speed.
As far as 32″ tires go, you’re maxed out at 31″ with the 4″ GDP lift. You CAN get up to 34″ tires with the 6″ GDP lift, 1.5″ forward offset A-arms, and SuperATV footwells.
If that 32″ tire size is really important to you, go for the 6″ GDP lift.
2021 Polaris, RZR XP 4 1000 Highlifter. I put 35 inch mud tires and I want to put a clutch kit on it. I was looking at the rev 1, but what is the difference between stage one and stage two?
Mostly riding in sand and mud.
Hi Jeff, great question. Depending on your machine, most stage 2 clutch kits include additional weights and/or a secondary helix for more precise clutch tailoring. For this kit, stage 2 adds a helix.
I need portals for my 2023 CFMOTO ZFORCE 950 HO EX with TEAM MSC stage 3 clutch kit.Could you tell me which SUPERATV portals would fit?
Have a polaris 2019 rzr turbo xp . I have put 32 inch tyres . And want a gear reduction of 12% and 25% hi /lo stages 2 and 3 questions are
Does this eliviate stress on machine
And will it be a bit better in start up in drive
And the last question do you have these parts
And price . If not can you steer me in the correct
Direction to purchase. Thankyou. Christopher
Hi Chris,
Get your OEM part number for your reverse shaft and give us a call so we can see if we have a kit that works for you! 812.574.7777
I have a 2024 polaris ranger crew xp 1000 premium I have a 4 inch s3 powersports lift and now looking to add portals keep going back and forth on the 4 or the 6 inch and what gear reduction to get anywhere appreciated
Hey Brice,
Give us a call and a tech can help you with this decision. 812.574.7777
we do mostly trail riding and in the spring and fall we hit the dunes, probably less than 4 times a year, i want to run 35 inch for the trails but don’t want to suffer when we hit the dunes. best gear reduction or no gear reduction? running 31 inch tires in the dunes, 2023 rzr xp 1000 turbo
Hey Robert,
If you’re going with a transmission, I’d recommend a 12% gear reduction. If you’re considering portals, I wouldn’t go any higher than a 15% reduction.
L have a 2016 polaris rzr900 highlifter L do a mix of trail plus mud what portals do you recomend?
Hey Larry,
It depends on what size tires you’re wanting to run! I wouldn’t recommend going higher than a 30% gear reduction.
33s I’m looking at the 4inch portals
Hey Larry,
If you’re doing a lot of mud riding, we suggest a 30%.
Im running a 2021 rzr xp4 1000 highlifter with 35″ bkts wanting to put 6in portals but bot sure what percent would be best
Hey Brian,
What style of riding do you typically do?
I installed one of your 12.5% reduction transmissions, with geared reverse, on a 2017 RZR XP 4 1000. I am running 30″ tires and would like to know if/what clutch kit I should get for trail riding. If you need to refer me somewhere else, that’s great too!
Hey E,
Give us a call so you can speak with a technician! 812.574.7777
I have a stock 2015 Polaris ranger 900 XP. I own 50 acres of woods/knobs up and down country. I have recently gotten stuck multiple times trying to traverse the hills. Even in 4 wheel drive in low gear all 4 tires just seem to want to spin and gets me stuck. What would help get me better traction , clutch kit, gear reduction kit? I currently have 26×9 r14 26×11 r 14 I was thinking about bumping up to 28s. I have also noticed a runner smell so I’m currently replacing the belt but I need help.
Hey T,
Right now you’re losing traction before power, and the hills make it worse. Bigger tires like 28s will actually hurt unless you re-gear, because they take torque away and make the belt slip (that burning smell). The biggest help is better, more aggressive tires and a clutch kit, which keeps the motor in the powerband and saves the belt. A gear reduction kit is great for steep woods riding, but it’s more money and usually a next step. I’d stick with 26s or 27s, upgrade the tires, replace the belt, and add a clutch kit—that alone will make a huge difference.