What Size Tires Fit a Stock CJ-7?

A stock CJ-7 will fit a 31x10.50R15 tire on the right wheel, and a 30x9.50R15 or 235/75R15 fits with room to spare. You'll hear "31s fit, it depends" from just about everybody. What it depends on comes down to two things most guides never put in front of you: which axle track your Jeep has, and how much your 40-year-old leaf springs have settled. The axle track decides how wide you can go and what backspacing you need. The springs decide how tall you can go before the rear wheel well catches the tire.

I've been mounting tires on CJs since they were new on the showroom floor. Most of the CJ-7s that roll into our shop in Long Beach today are wearing a mismatch: the wrong backspacing for their axle, or 31s stuffed under springs that gave up years ago. Let's sort out yours.

The Two Things That Decide Your CJ-7 Tire Size

Find your Jeep in the left column. The year tells you the axle track. The spring check is something you can do in your driveway in five minutes, and I'll show you how further down.

Feature	Fits Clean	Biggest on Stock Suspension	Wheel to Run
1976-1981 narrow-track, healthy springs	235/75R15 or 30x9.50R15	31x10.50R15, only with shallow backspacing	15x8, about 3.5 in backspacing
1982-1986 wide-track, healthy springs	30x9.50R15 or 31x10.50R15	31x10.50R15; 32s need rear trimming	15x8, about 3.75 in backspacing
Any year, sagged springs	225/75R15 or 235/75R15	30x9.50R15 until the springs are replaced	Factory 15x7 or a 15x8
Any year, concours or period-correct restoration	H78-15 bias-ply or 225/75R15 radial	Stay with the factory size	Factory steel or styled wheel

The second table sorts by how you use the Jeep. That's the question that tells you which tire to put on the order sheet once the size is settled.

Feature	Best Size	Why
Weekend cruiser, mostly pavement	235/75R15	Light, quiet, keeps factory gearing close, widest choice of all-season tread
Mixed street and dirt road	30x9.50R15	Fills the wheel well, clears everything on stock springs, minimal gearing hit
Real trail use	31x10.50R15	The classic CJ size; deepest selection of all-terrain and mud-terrain tread
Restoration or show	H78-15 bias-ply or 225/75R15	Matches what the Jeep wore when it left Toledo

What Size Tires Came on a CJ-7 From the Factory?

The CJ-7 ran from 1976 through 1986, and the factory tire changed with the times. Early Jeeps rolled out on bias-ply and bias-belted letter sizes like H78-15, roughly 27.5 inches tall. As radials took over, the standard fitment moved to metric sizes from 205/75R15 up through 235/75R15, depending on year and trim. Renegade and Laredo packages generally wore the bigger 235/75R15 on styled wheels, while base Jeeps often made do with something narrower on plain steel.

Every CJ-7 used a 15-inch wheel on a 5x5.5 bolt pattern. That bolt pattern is your friend, because it is shared with a long list of trucks and Jeeps, and wheel selection in 15-inch 5x5.5 is still deep today. If you're shopping wheels, our 5x5.5 wheel guide covers what else shares that pattern.

Feature	Overall Diameter	Tread Width	Where It Fits
H78-15 (bias)	about 27.5 in	about 8 in	Factory; restoration
205/75R15	27.1 in	8.1 in	Factory base
215/75R15	27.7 in	8.5 in	Factory base
225/75R15	28.3 in	8.9 in	Factory; fits every CJ-7
235/75R15	28.9 in	9.3 in	Factory Renegade and Laredo; fits every CJ-7
30x9.50R15	about 29.9 in	9.5 in	Stock suspension, any year
31x10.50R15	about 30.8 in	10.5 in	Stock suspension with healthy springs and the right backspacing
33x12.50R15	about 32.8 in	12.5 in	Needs a lift

The 235/75R15 is the easiest upgrade on a CJ-7 and is still one of the most widely stocked 15-inch light truck sizes on the market. It's about 28.9 inches tall. You can see how it measures against the others in our 235/75R15 in inches breakdown.

Will 31x10.50R15 Tires Fit a Stock CJ-7?

Yes, with conditions. The 31x10.50R15 is the size every CJ owner asks about, and on a healthy Jeep with the right wheel, it fits without a lift. It is also the deepest flotation size in the 15-inch market, so you will have more tread choices here than in any other CJ size, from highway all-terrains to full mud-terrains.

Here are the conditions. The springs need to be holding factory ride height. The wheel has to put the tire where it clears the front leaf spring at full lock. And you have to accept that hard articulation off-road may still kiss the rear wheel well opening. On a Jeep that only sees pavement and graded roads, that last point may never come up.

The flotation sizing tells you the tire's real numbers right on the sidewall: 31 inches tall, 10.50 inches wide, 15-inch wheel. Measured, most 31s come in closer to 30.5 to 30.8 inches mounted. If you're cross-shopping metric sizes against it, our 31x10.50R15 equivalent chart lines them up.

On load, you don't need to overbuy. A CJ-7 is a light machine. Nearly every 31x10.50R15 is built as a Load Range C light truck tire rated at 109, or 2,271 pounds per tire at 50 psi. Four of them carry more than twice what a fully loaded CJ-7 weighs. Going to a heavier ply rating only makes a short-wheelbase Jeep ride harder.

Do Narrow-Track and Wide-Track CJ-7s Take Different Tires?

They do, and this is the part almost nobody mentions. In 1982, AMC widened the CJ-7's axles. The narrow-track axles used from 1976 through 1981 measure about 53 inches from wheel mounting surface to wheel mounting surface. The wide-track axles that arrived for 1982 measure about 56 inches up front. That puts each front wheel roughly 1.5 inches farther out on a 1982-1986 Jeep.

The frame and leaf springs didn't move. So on a narrow-track Jeep, the same wheel and tire sits 1.5 inches closer to the front spring and the frame. Bolt a wheel with deep backspacing on a 1979 CJ-7 and the inside sidewall of a 31x10.50 rubs the spring when you crank the wheel. Put that same wheel on a 1984 and it clears.

That's why two CJ-7 owners can run the exact same 31s and tell you completely different stories. One has a wide-track Jeep and never rubs. The other has a narrow-track and chewed up a sidewall in the first parking lot.

How to tell which axles you have

Start with the model year on the title, then confirm it at the axle. If someone swapped axles over the years, the year won't tell you the truth. Measure from the face of one front hub to the face of the other. Around 53 inches means narrow-track. Around 56 inches means wide-track. While you're under there, look at the rear cover: a round 12-bolt cover is the AMC 20 that most CJ-7s used, and an odd-shaped 10-bolt cover usually means a Dana.

What it means for tire width

On a narrow-track Jeep, the inside clearance is your limit. Use a shallower backspacing wheel to push the tire outward, away from the spring. On a wide-track Jeep, the outside clearance becomes the limit, so watch how far the tread sticks past the fender or flare. Many Renegade and Laredo models wore factory plastic flares, which buys a little room on the outside.

How Do Tired Leaf Springs Change What Fits?

The youngest CJ-7 on the road is about 40 years old. Leaf springs that age have almost always settled. Every inch of sag is an inch less room between the top of the tire and the wheel well when the suspension compresses.

Owners who've been at this a while will tell you the rear wheel well is where a stock CJ-7 runs out of room for diameter. The rear opening is the tightest, and the rear springs carry the most weight, so they settle first. A Jeep that fit 31s comfortably in 1985 may only clear 30s today without a hint of rubbing.

The five-minute spring check

Park on level ground with a normal load: fuel in the tank, spare tire mounted. Measure from the center of each hub straight up to the edge of the wheel opening. Do all four corners and write the numbers down.

Then look for these signs: one corner sitting noticeably lower than its opposite, rear leaves that look flat or reverse-arched instead of curved, and shiny or crushed bump stops. If the rear sits more than about an inch lower than the front, or one side sits low, plan on springs before you plan on 31s.

New stock-height springs are one of the best things you can do for an old CJ anyway. They bring back the ride height, the handling, and the room in the wheel well. If you want to know how far a factory-height truck can go in general, our biggest tire without a lift guide covers the same logic across other trucks.

What Wheel Width and Backspacing Does a CJ-7 Need?

The factory wheel on most CJ-7s was a 15x7. That works fine for 225/75R15, 235/75R15, and 30x9.50R15. For a 31x10.50R15, step up to a 15x8. A 10.50-wide tire is designed around a rim in the 7 to 9-inch range, and the 8-inch wheel holds the sidewall in its intended shape, gives the bead good support, and sets the tread flat on the ground.

Backspacing is the measurement from the wheel's mounting face to its inner edge. Less backspacing pushes the tire outward. More backspacing pulls it inward toward the spring.

Feature	Wheel	Backspacing Starting Point	What You're Clearing
Narrow-track, 31x10.50R15	15x8	About 3.5 in	Front leaf spring and frame at full lock
Wide-track, 31x10.50R15	15x8	About 3.75 in	Balance between spring inside and flare outside
Any track, 30x9.50R15 or 235/75R15	15x7 or 15x8	Factory or close to it	Narrower tire clears without changes

Treat those as starting points, not gospel. Forty years of bent spring hangers, swapped steering boxes, and aftermarket shackles mean every CJ is a little different. Mount one tire, turn lock to lock, and look at the gap to the spring before you mount the other three. If 15x8 is a new measurement to you, our 15x8 wheel explainer walks through width, diameter, and offset.

One more thing on wheels. Don't go wider just to look tough. A 15x10 wheel on stock suspension pushes a 31 way out past the body, throws mud and rocks down the side of the Jeep, and loads up the wheel bearings and ball joints on a Dana 30 that wasn't built for it.

Can a Stock CJ-7 Run 32 or 33-Inch Tires?

Not without changes. A 32x11.50R15 on a wide-track CJ-7 with fresh springs is the absolute edge, and most owners who try it end up trimming the rear wheel opening. Selection in 32x11.50R15 is also thin compared to 31s, so you give up tread choices for an inch you'll rub on.

A 33x12.50R15 needs a lift, period. Most CJ owners running 33s are on about 4 inches of spring lift, and with the right backspacing and some fender work, a 2.5-inch lift can get there too. That's also the point where the gearing math stops being optional, which we'll get to next.

If you're planning a lift anyway, pick the tire first and build the lift around it. It is a lot cheaper than buying a lift, finding out the tire still rubs, and buying a second lift.

What Bigger Tires Do to CJ-7 Gearing and Speedometer

CJ-7s left the factory with a range of axle ratios. The common ones are 2.73, 3.31, and 3.54, depending on engine and year. A lot of six-cylinder and V8 Jeeps got the tall 2.73s for highway mileage, and those Jeeps feel bigger tires the most.

When you put on a taller tire, the effective gear ratio drops. Here's how a factory 225/75R15 at 28.3 inches compares once you move up:

Feature	30x9.50R15	31x10.50R15	33x12.50R15
2.73 factory ratio	Feels like 2.58	Feels like 2.51	Feels like 2.35
3.31 factory ratio	Feels like 3.13	Feels like 3.04	Feels like 2.85
3.54 factory ratio	Feels like 3.35	Feels like 3.25	Feels like 3.05

A 3.54 Jeep handles 31s just fine. A 3.31 Jeep feels it on hills but lives with it. A 2.73 Jeep on 31s is a dog off the line, lugs in top gear, and gives back any mileage you hoped to save. To find your ratio, lift both rear tires, put the transfer case in neutral, mark the driveshaft, and turn both tires one full turn together in the same direction. The number of driveshaft turns is your ratio. When it's time to fix it, our regear after bigger tires guide covers what to change and when.

Your speedometer reads low with bigger tires, too. CJ-7s use a mechanical speedometer driven by a gear in the transfer case. Going from a 28.3-inch factory tire to a 31 makes the speedometer read about 8 percent low: 55 on the dash is about 60 on the road. The fix is a different driven gear in the transfer case, an inexpensive part and a short job.

What the Wrong Size Costs You on a CJ-7

Getting the size wrong on a CJ doesn't fail all at once. It nickels and dimes you, and every step costs more than the last.

Stage 1: The rub you can hear

It starts with a scuff at full lock in the grocery store parking lot, or a thump from the rear on a driveway dip. That's tire against spring, frame, or wheel well. Most owners ignore it.

Stage 2: Sidewall damage

A sidewall that rubs the same spot on every turn wears through its outer rubber, then starts exposing cords. Sidewall damage can't be patched. That tire is done, no matter how much tread is left.

Stage 3: Body and steering wear

Rubbing the rear wheel opening cracks old fiberglass or plastic flares and chews up sheet metal that's hard to replace on a 40-year-old Jeep. Up front, extra tire weight and too little backspacing load the steering box, tie rod ends, and Dana 30 ball joints harder than they were designed for.

Stage 4: Gearing you have to fix

Tall tires on 2.73 gears mean slipping clutches, overheating in traffic, and a transmission working too hard. Eventually you're paying for a regear you never budgeted.

Stage 5: Buying tires twice

Add it up and it all ends the same way: a set of tires that didn't fit, sold cheap or tossed, and a second set in the size you should have bought the first time. Spending ten minutes with a tape measure is the cheapest part of this whole job.

How to Pick the Right Tire for Your CJ-7

Here's the order I'd walk a customer through at the counter.

Step 1: Confirm your axle track

Check the year, then measure hub face to hub face up front. About 53 inches is narrow-track; about 56 is wide-track.

Step 2: Check your springs

Measure hub center to wheel opening at all four corners on level ground. Low or uneven corners mean springs come before bigger tires.

Step 3: Find your gear ratio

Count driveshaft turns or read the tag on the axle. 2.73 Jeeps should think hard before going past 30s.

Step 4: Pick the size for how you drive

235/75R15 for pavement, 30x9.50R15 for mixed use, 31x10.50R15 for trail work on a healthy Jeep. Restorations stay with the factory size, and bias-ply is available for show Jeeps. If you're weighing bias against radial, our radial vs. bias-ply comparison lays out the trade-offs.

Step 5: Match the wheel

15x7 for the smaller sizes, 15x8 for 31s, with backspacing set for your axle track.

Step 6: Test fit one corner

Mount one tire, turn lock to lock, and bounce the corner if you can. Then mount the rest.

Conclusion

The honest answer to "what fits a stock CJ-7" is a 31x10.50R15 on a 15x8 wheel, with two big conditions: your Jeep needs springs holding factory height, and your wheel needs backspacing that matches your axle track. Narrow-track Jeeps from 1976 through 1981 need the tire pushed outward, away from the front spring. Wide-track Jeeps from 1982 through 1986 have that extra 1.5 inches per side and are more forgiving.

If your springs are tired, run a 30x9.50R15 or 235/75R15 until they're replaced. If your Jeep is a show piece, stay with the factory size. And if you're dreaming about 33s, buy the lift and the gears before you buy the tires.

When you know your size, take a look at our classic tire collection. We've been putting rubber on CJs since they were new, and we're happy to help you sort out the rest.

Key Takeaways

Here's what to remember before you order tires for a CJ-7.

• 31x10.50R15 is the stock-suspension limit: It fits on a 15x8 wheel when the springs are healthy and backspacing matches the axle track.
• Axle track changes the answer: 1976-1981 narrow-track CJ-7s sit about 1.5 inches closer to the springs per side than 1982-1986 wide-track Jeeps.
• Sagged springs shrink the limit: Old leaf springs cost you wheel well room, and the rear opening runs out first.
• Gearing matters on 2.73 Jeeps: 31s turn a 2.73 into roughly a 2.51, which feels sluggish on a CJ.
• Don't overbuy load range: Load Range C 31s carry far more than a CJ-7 weighs and ride better than heavier ply ratings.

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