Can you fit 33-inch tires on a Jeep Wrangler JK with a stock suspension? Is the backspacing enough to accommodate the bigger tires? Will you be able to go off-road with 33″ on a stock suspension? How does bigger tires affect the handling and performance?
33-inch tires can be fitted to a stock Jeep Wrangler JK, but with minimum clearance on the front bumper and not enough clearance for full articulation off-road.
Before running out and fitting bigger tires to your JK, make sure you understand all the implications and that there are other factors that comes into play such as backspacing, clearance, fuel economy, handling and more. This article will discuss what you can expect when fitting 33-inch tires to a stock Jeep Wrangler JK.
Jeep Wrangler 33 inch tires – No Lift
The Stock JK design and wheel fenders offers quite a bit of clearance up front. There is no touching when the vehicle is driving in and around town. The rear tires are never really a problem since there’s more than enough clearance and they are not required to turn directionally.
If possible, fitting slightly wider aftermarket rims will help with backspacing especially if it had a slightly more negative off-set. Its not recommend to fit wider tires on the stock rims, since there will be very limited clearance and more rubbing at full lock and especially when off-roading.
click here to find out what is the largest tire you can fit on a Jeep Wrangler.
If you ever intend on going off-road then you will need to do a few more modifications to the the vehicle to make the 33-inch work properly since 33’s are slightly too big for maximum articulation (flex) without any body scrub on a stock suspension. If you’re simply doing the big tire upgrade for aesthetics and the occasional gravel roads, then 33 inch tires can work on a stock suspension.
Will 33-inch Tires Scrub Off-road on a Stock JK?
When it comes to heavy off-road trails, which many Jeep owners are well known for, you will require maximum suspension articulation and enough clearance inside the wheel area. In this instance the stock stock suspension will not work the best. You will be wise to upgrade your suspension first to accommodate the bigger wheels and allow for maximum flex through and over obstacles. We recommend a minimum 2-3″ suspension lift to allow for better clearance and “fllex” without scrubbing.
Being a SFA (Solid Front Axle) vehicle, there are no issues with upper control arms and CV angles to worry about. Many JK owners have successfully fitted 33-inch tires on a stock JK. The amount of scrub depend largely on what the intended application. Disconnecting front sway bars, most definitely results in body scrub with a stock suspension setup while off-road.
So, if you want to fit a larger but not wider tire on the stock suspension and still have no issues off-road and achieve full flex without scrubbing you are pretty much limited to 255/80/17. This is basically the same width as the stock JK tire but with a higher sidewall. This will improve your ground clearance and lift the diff higher off the ground and offer improved clearance on other lower hanging steering components.
Bottom line here, if you fit tires much wider than the 11” tire on stock wheels, your chances of making contact with your rear sway bar end link is high. It is advised to fit a small wheel spacers to rectify this issue.
How Does 33’s Affect Fuel Consumption?
Big tire upgrades will definitely affect the gas mileage, and of course have a direct impact on your wallet too. The bigger heavier tires falls part of the unsprang weight of the vehicle. This is the quickest way to increase fuel consumption.
Unsprang mass/weight refers to the mass/weight of the suspension, wheels and other components directly connected to them, that sits below the suspension, rather than being supported by it.
You can expect to lose at least 1 mpg at a minimum with 33-inch tires. The heavier taller than stock tires are wider with more tire surface hitting the road surface, resulting to more drag and rolling resistance. Of course, the tread pattern also plays a major role since a more aggressive MT (Mud Terrain) tire choice will be louder and result in higher rolling road resistance which means less mpg.
Start adding heavier aftermarket bumpers, winches and other accessories and the side-effects soon become more and more obvious.
click here to find out the weight effects an aftermarket bumper has on your vehicle.
Will 33″ tires affect the JK’s Handling?
With the bigger tires, you’ll also feel a difference in the steering feel. It will feel more stable and cornering will feel slightly better, however you can expect to feel a heavier steering. The bigger heavier tires also results in a slightly more under steer feel.
Increased un-sprung weight will result in decreased handling while by reducing un-sprung weight is the key to improving handling. The lower the un-sprung weight, the less work the shocks and springs have to do to keep the tires in contact with the road over bumpy surfaces.
Then there’s your braking. Something many people don’t even consider before fitting bigger tires. You’ll feel the braking is not as crisp as it was with the stock tires. A Lot of problems, if not all of them are caused by inertia. more weight means higher inertia. Higher inertia results in decreased stopping ability with the stock JK brakes. Bear in mind its not going to be very obvious, however, if you know your vehicle very well and drive it daily, you definitively will notice it.
Wear on Other Components With Oversized Tires
Components that will can affected by fitting bigger tires are:
- Fuel Consumption
- Steering components
- Gearing Ratios
- Torque on the wheels
The bigger you go the more obvious these side-effects becomes. With 33″ tires on a JK you wont feel most of the above-mentioned effects, since the vehicle can handle the 33’s comfortably. However, once you opt for 35, 37 and bigger, your vehicle will not perform optimally without additional upgrades on your suspension, steering and drive-train components to make the whole setup work 100%.
In some cases bigger, isn’t always better!
Does the JK Have Enough Backspacing to Accommodate 33″ Tires?
Having the correct backspacing is crucial when fitting 33″ tires and is often a factor that most dont speak about. But first lets understand backspacing.
The backspacing on stock JK wheels is 6.25″. That means that the mounting surface of the wheel is 6.25” from the rear lip of the wheel. This is just enough to accommodate the 33″ however your clearance on the front bumper might be very minimal, depending on the tire tread pattern, thickness and mold design. All tires are not created equally and tire manufactures use different molds, so clearance will vary greatly based on make and tread pattern here.
Backspacing is the distance from the hub mounting surface (usually in the center of the rim) to the inside lip of the wheel (measured in inches). Positive backspacing puts the tire closer to the hub of the truck. A Rim with more negative backspacing pushes the wheel outward. Hence a rim with a closer to 0 or negative offset will sit further out and allow you to fit wider tires. There will be a few inches of tire poking out.
Always make sure you check your state laws regarding maximum tire “poke”. Certain countries are very strict with this law.
Fitting 33-inch tires is something that can be successfully done on the JK Wrangler without much hassles. This will obviously depend on your intened application. Fit aftermarket rims with a more negative offset to be safe. If you intent to venture offroad, doing rough tracks and rock crawling, you’ll have to do suspension upgrade first to take advantage of the Jeeps legendary articulation ability.