If you’re a Jeep Grand Cherokee Summit owner or planning to become one, you’ve probably wondered about upgrading your tires or wheels. One common question that pops up is: Can you run 275/55/R20 tires on the Grand Cherokee Summit? The short answer? Yes, you can — but there are a few important things to keep in mind before making the switch.
This guide will walk you through everything you need to know about putting 275/55/R20 tires on your Grand Cherokee Summit in a simple, straightforward way. No complex terms — just helpful info.
What Is the Jeep Grand Cherokee Summit?
The Summit trim is one of the highest levels of the Jeep Grand Cherokee lineup. It blends luxury with Jeep’s rugged performance. From ventilated leather seats and real wood accents to advanced safety features and a high-end sound system, the Summit feels more like a luxury SUV — but still has the off-road chops Jeep is known for.
Under the hood, many Summit models come with a 3.6L V6 engine, though some higher trims offer a V8. It’s also equipped with an air suspension system, Quadra-Trac II 4×4, and Selec-Terrain traction management. All these systems play a role when you’re thinking about changing tire size.
Understanding Tire Sizes: What Does 275/55/R20 Mean?
Before we get into how the 275/55/R20 tire fits your Grand Cherokee Summit, let’s break down what these numbers actually mean:
- 275: This is the tire width in millimeters. So, it’s 275 mm wide.
- 55: This number refers to the sidewall height. It’s a percentage of the width. In this case, 55% of 275 mm.
- R20: This is the rim diameter. The tire is meant to go on a 20-inch wheel.
Now, the stock tire size for many Grand Cherokee Summits is around 265/50/R20. That makes the 275/55/R20 slightly taller and wider. Let’s dig into what that means for your vehicle.
Will 275/55/R20 Tires Fit a Grand Cherokee Summit?
1. Clearance and Space
Yes, they fit — but it’s tight. The 275/55/R20 tires are about 1.3 inches taller and a bit wider than stock ones. In most cases, you won’t need any modifications, especially if your Jeep has the air suspension system. But in Off-Road 2 mode or full lock turning, you might experience slight rubbing, especially if you’re using aftermarket wheels with less backspacing.
2. Suspension Considerations
If you’re using the standard Quadra-Lift air suspension, you’re in better shape. The vehicle can adjust its height depending on terrain, which helps avoid rubbing. But if you’ve got a fixed-height suspension or your air suspension is aging or sagging a bit, it’s something to monitor.
3. Speedometer and Odometer Impact
Because the tire is taller, it will slightly throw off your speedometer and odometer. You’ll be going a little faster than what your dash says. The difference isn’t drastic, but it’s good to know. For example, if your speedometer says 60 mph, you might actually be doing around 62 mph.
4. Handling and Ride Feel
The ride may feel a bit softer. That’s because taller tires generally absorb bumps better. On the flip side, steering might feel slightly less sharp — not a deal-breaker, but something you may notice on tight turns.
Pros of Upgrading to 275/55/R20 Tires
Let’s talk benefits. Why do people go for this tire size?
Better Ground Clearance
The taller tire gives your Grand Cherokee a bit more height. That’s helpful if you drive on rough roads, dirt trails, or during snowy winters. It makes the SUV feel even more ready for adventure.
Improved Off-Road Capability
Wider tires give you more surface area, which can improve traction on gravel, sand, and other loose surfaces. You’ll feel more planted, especially during light off-roading or camping trips.
Enhanced Road Presence
Let’s be real: they look good. The beefier stance fills out the wheel wells better, giving your Grand Cherokee Summit a more aggressive and confident appearance.
Potential Downsides You Should Know
While the upgrade has its perks, there are a few trade-offs to consider.
Fuel Efficiency
Bigger tires can weigh more. That adds rolling resistance and might slightly reduce your miles per gallon. If you’re a city driver doing a lot of stop-and-go, the impact could be more noticeable.
Rubbing in Extreme Conditions
We mentioned this earlier, but it’s worth repeating. If you’re off-roading in Off-Road 2 mode or making sharp U-turns, rubbing could happen. It’s usually just the inner plastic fender lining — nothing serious, but annoying if you’re particular about sounds or wear.
Speedometer Accuracy
As discussed, the change in tire diameter affects your speed readout and mileage count. It’s minor but can become relevant over time or for trip planning.
Tire Brands to Consider for 275/55/R20
When picking new tires, think about how and where you drive. Here are some solid choices based on driving style:
Daily Commuter (Mostly City & Highway):
- Michelin Defender LTX M/S
- Continental TerrainContact H/T
These offer a quiet ride, good tread life, and solid wet traction.
All-Terrain & Weekend Trail Explorer:
- Falken Wildpeak A/T3W
- BFGoodrich All-Terrain T/A KO2
Great for those weekend getaways or rougher roads without going full rock-crawler.
Winter Focused:
- Bridgestone Blizzak DM-V2
- Nokian Hakkapeliitta R5 SUV
If you’re dealing with harsh winters, these are some of the best in snow and ice.
Do You Need a Lift Kit or Spacers?
Good news: for most drivers, no lift kit is needed. The Grand Cherokee Summit already sits higher than many SUVs, especially with air suspension. However, if you want to go bigger than 275/55/R20 or add aggressive off-road tires with chunky sidewalls, that’s when you might want to consider a small leveling kit or wheel spacers to avoid rubbing.
What About Warranty and Safety?
If you’re worried about factory warranties or insurance, tire upgrades like this usually don’t void anything. But check with your local dealership just to be sure. Most dealers won’t bat an eye unless the tire causes damage or alters major suspension components.
In terms of safety, as long as you stay within reasonable tire sizing limits — and 275/55/R20 is well within that range — you’re good to go.
Final Thoughts
Upgrading your Jeep Grand Cherokee Summit to 275/55/R20 tires is a popular and practical move. It gives you a stronger stance, a bit more ground clearance, and better off-road performance without major downsides. Just make sure you’re aware of potential speedometer differences and keep an ear out for rubbing when turning tightly.
The Grand Cherokee Summit is already a great mix of style and strength — these tires just add a little more muscle to the mix.
FAQs
Q: Will 275/55/R20 tires void my Jeep warranty?
A: Usually, no. But it’s smart to double-check with your local dealership.
Q: Do I need to recalibrate my speedometer?
A: It’s optional. The change is small, but a shop can recalibrate if you want accuracy.
Q: Can I use these tires in snow?
A: Yes, but go with a winter-specific tire if snow is common where you live.
Q: Will these tires rub on full lock?
A: Possibly, especially in Off-Road 2 height or during tight turns. Most owners find it manageable.
Q: Do I need new wheels too?
A: Not necessarily. Most 275/55/R20 tires fit fine on factory 20″ Summit wheels.