So, you want to fit bigger tires to your Jeep Gladiator and want to know what the biggest size is you can get away with without doing too many additional modifications. This article will discuss the biggest tires you can fit on the Gladiator Sport and Rubicon models and what is required to make them fit with and without a lift kit.
The biggest tire size you can fit a stock Jeep Gladiator Rubicon is 35” without any additional modifications. You can run 285/75-17 or roughly 33.8” on stock Gladiator Sport models without a lift kit.
Fortunately, the Gladiators have a lot of room for modifications and can accommodate a wide variety of tire sizes due to their suspension setup and arch clearance. This, however, does not mean you should try and squeeze the biggest tire onto the vehicle. You should ask yourself what the main application of the vehicle is for example, will you be towing, overlanding, show and shine, or doing serious off-roading aka “wheeling”. Each application has a different tire size recommendation.
For the sake of the conversation/article, let’s assume you want the biggest tire that covers both on-road and off-road applications.
Are 35s and 315 tires the same? Differences (Size/weight/Height)
Table of Contents
Biggest tires to fit a stock Jeep Gladiator (Without a Lift kit)
The next section of this article looks specifically at the Jeep Gladiator Sport derivative. We look at what the biggest tire size you can fit without a lift kit and also what additional modifications you’ll need to do to fit 35-inch tires.
Biggest tire on a Jeep Gladiator Sport S
Being a pickup truck, the rear suspension of the Gladiator sits roughly 1.5 inches taller than the front. It is designed that way to allow you to load up the rear to the maximum carrying capacity and allow the truck to level out with the front without too much rear droop.
What happens when your rear sits lower than the front?
If the rear of the truck bed sits level or lower when heavily loaded, your headlights will shine directly into oncoming traffic. Your truck’s steering will also become rather vague and understeer more than usual. It’s for this reason you have 1.5” more clearance in the rear than the front. This also means you can easily fit larger tires in the rear without too much hassle. So, there’s no need for spacers or leveling kits in the rear. If you don’t intend on towing a heavy trailer or loading the rear up too much, you can install a ¾-inch leveling kit in the front for some additional lift up front, but it’s not necessary. This is purely for aesthetics.
There are unfortunately some cons to fitting bigger, heavier tires.
Fitting bigger heavier 35-inch tires to your Jeep Gladiator will negatively affect the following:
- Gas mileage
- Braking distance
- Acceleration performance.
Read: 33s vs 35s (Size/Weight/Height)
Also, because of the stock narrow fenders on the Sport models, you will have a major increase in tire poke which is illegal in certain states in the US. You will also experience some light scrubbing on the front plastic trim on the bumper at full lock. You have to remove the aero-wing plastic bits from the bumpers since they make contact when turning and at full lock. Consider a wide fender upgrade when fitting 35s to your Gladiator Sport. The wheel clearance or backspacing is perfectly fine with enough space for full steering lock without any scrubbing.
Remember, this might be able to fit with some light trimming and cutting of plastic bumper bits, but this is by no means the best setup for off-road applications. Off-road you’ll want to take advantage of the Gladiators’ excellent articulation so you will need to fit a lift kit of minimum 2-2.5 inches to get the maximum benefit when wheeling with your 35” tires.
When running stock wheels and stock suspension on your Gladiator Sport you can safely consider the following sizes without any additional modifications:
- 285/70,17
- 295/70,17
- 285/75,17
Read: 33s vs 285 Tires (Size/Weight/Height)
If you are considering going as big as 315/70,17 on your Sport then be prepared to have minor rubbing and you’ll reach the maximum that you can go on a stock Sport with stock wheels.
Biggest Tire on a Gladiator Rubicon
Rubicon has more fender clearance and a raised suspension in stock format than the Gladiator Sport. 35” tires fit easily on the Gladiator Rubicon models without any additional modifications. On the Rubicon/Mojave models, a lift kit is not necessary for 35s and the transmission ratios of 4.10 are short enough to pull the heavy 35s without any hassles. 35” tires are definitely the most practical all-rounders for towing, off-road, and daily driving applications. They look pretty good too.
If you intend on going bigger than 35-inch tires like say, 37-inch then you’ll need to do a few more modifications and fork out a lot more of your hard-earned cash to make them function properly.
Will a Gladiator Rubicon’s Tires fit a stock Gladiator Sport?
Yes, stock Rubicon tires are roughly 33 inches in size. They are 285/70/17 and only 0.25” or 6.35 millimeters taller than the stock 245/75/17 Sport/Sahara/Overland tires. This means that Rubicon tires are compatible with any Gladiator Model without any additional modifications to make them fit.
Speedometer Reading between 33” and 35” tires
The below table will give you an indication of how the speedometer reading is affected between a 33” and a 35”.
| 33” Speedo reading | 20mph | 30mph | 40mph | 50mph | 60mph | 70mph | 80mph | 90mph |
| 35” Speedo Reading | 21.3mph | 32mph | 42.7mph | 53.4mph | 64mph | 74.7mph | 85.4mph | 96mph |
WATCH – Fitting 35’s on a Gladiator Sport (VIDEO)
Difference Between 33″ and 35″ Tires (Size/Height/Weight)
When it comes to big tire upgrades, everyone seems to be hell-bent on oversized tires and big lifts. This article will discuss the pros and cons of 33” tires vs 35” tires and the physical differences between the two. How big of a difference does that extra 2″ of tire clearance make on the trail?
A 35” tire offers approximately 1 inch more clearance at the axle compared to a 33-inch tire.
Now that might not sound like a lot, however, that 1 inch can mean the difference between being hung up and just managing to scrape over the obstacle. So are big tires the holy grail of off-roading or are there other components and factors that are just as important, if not even more so.
Let’s find out!
User Experience & Feedback
User 1
34″ tires on stock wheels with stock bumper Sport S Max Tow, mine rubbed when max turn left or right and off-road with moderate suspension articulation. Latter I added a 2.5″ lift, and still got/get a little rubbing in the front with moderate articulation and max turning, but rare. Wheels with an offset would help eliminate this, I have cut the wings off bridging that gap between the front fenders and stock bumper. New steel, the winch-capable bumper is on the way, and that will eliminate the occasional off-road rubbing at max turn and articulation.
https://www.jeepgladiatorforum.com/forum/threads/largest-tires-on-an-unlifted-sport.23924/
User 2
285/75r17 Falken wildpeaks with 17×7.5 rubicon rims… no rubbing and didn’t have to remove anything. The tires are just under a 34 but look a lot larger than 285/70r17s. I attached a comparison of the two.
https://www.jeepgladiatorforum.com/forum/threads/largest-tires-on-an-unlifted-sport.23924/
User 3
If you intend to tow I wouldn’t go over a 33. Just my opinion by the power loss w/35s tends to make owners complain on this forum about regearing and/or looking for more mpg. i also have a jtmt and wont be going over 285/75/17z
https://www.jeepgladiatorforum.com/forum/threads/largest-tire-size-max-tow-without-lift.47041/
Resources
- https://www.jeepgladiatorforum.com/forum/threads/largest-tires-on-an-unlifted-sport.23924/
- https://www.jeepgladiatorforum.com/forum/threads/largest-tire-size-max-tow-without-lift.47041/
Conclusion
In conclusion, fitting bigger wheels to your Gladiator will improve the looks, handling, and overall off-road and towing performance if done correctly. Make sure you remain within the manufacturer’s specifications for the best results. Unfortunately, it’s not all roses. When fitting oversized tires to any vehicle you must be prepared for a drop in acceleration, braking, and decreased gas mileage. With that being said, it’s still a worthwhile modification if you do it properly.