You've probably seen them a thousand times on the front of a zero-turn mower or a high-end garden cart without ever really thinking about the numbers stamped on the sidewall. The 11 x 400 5 tire is basically the unsung hero of the landscaping world. It's small. It's chunky. It’s also the primary reason your lawn doesn't look like a dirt track after you finish mowing on a Saturday morning.
Most people don't care about these tires until they go flat. Then, suddenly, you're staring at a "11x4.00-5" engraving and wondering if that extra zero matters or if you can just shove a harbor freight special on there and call it a day. Honestly, the sizing is simpler than it looks, but getting it wrong means your mower deck sits crooked, your cut looks like a jagged mess, and you're out sixty bucks for no reason.
Decoding the 11 x 400 5 tire sizing mystery
Let's break down these numbers before you go buying the wrong thing. The first number, 11, is the overall height of the tire when it's fully inflated. It’s roughly 11 inches tall. The second number, 4.00, is the width across the tread. The last number, 5, is the rim diameter.
It sounds straightforward. It isn't always.
If you buy a "cheap" version of a 11 x 400 5 tire, you might find that it actually measures 10.5 inches or maybe 11.2 inches. On a car, half an inch is nothing. On a zero-turn mower like a Scag Liberty Z or a John Deere Z300 series, that half-inch difference makes the front of your mower dip. You’ll end up with a "scalped" lawn because one side of the deck is lower than the other. Manufacturers like Carlisle or Kenda actually stick pretty close to the specs, but the off-brand stuff you find in the dusty corner of a big-box store? It’s a gamble.
The "5" is the most rigid part of the equation. If you have a 5-inch rim, you need a 5-inch tire. Period. You can't stretch a 4-inch tire on there, and a 6-inch tire will just flop around like a loose shoe.
👉 See also: Executive desk with drawers: Why your home office setup is probably failing you
Smooth vs. Ribbed: Which tread actually wins?
You’ll usually see two main types of tread for the 11 x 400 5 tire.
Smooth tires look like racing slicks. They’re common on the front of commercial zero-turns. Why? Because when you’re whipping a 700-pound machine around a tight corner, you don't want the front tires digging into the turf. A smooth tire slides just enough to prevent "turf tear." If you have a perfectly manicured lawn with soft soil, smooth is your best friend.
Then you have the ribbed tires. These have those vertical grooves running along the circumference. They provide a bit more "bite" for steering. If you’re mowing on a slight incline or dealing with damp grass, smooth tires can sometimes act like skis, leading to a loss of steering control. Ribbed tires give you that extra bit of directional stability.
I’ve talked to guys who swear by the Carlisle Turf Saver series for this size. They aren't the cheapest, but they don't dry rot in two seasons like the no-name versions do. If you're tired of plugging holes every spring, spending the extra ten dollars on a 4-ply rated tire instead of a 2-ply is the smartest move you’ll make all year.
The ply rating trap
Most 11 x 400 5 tire options come in 2-ply or 4-ply.
✨ Don't miss: Monroe Central High School Ohio: What Local Families Actually Need to Know
A 2-ply tire is basically a balloon. It’s thin, soft, and punctures if you even look at a locust thorn the wrong way. A 4-ply tire is significantly tougher. It has a higher load capacity, which matters if you’re using a heavy commercial mower or a cart filled with wet mulch.
Check your sidewall. If it says "Load Range B," that's usually your 4-ply. If it says "Load Range A," it’s a 2-ply. For most residential use, 2-ply is fine until it isn't. But if you have "puncture-prone" property—lots of brush, thorns, or debris—4-ply is a non-negotiable upgrade. Some people even go for the "flat-free" semi-pneumatic versions, but be warned: those ride like a brick. You’ll feel every pebble in your spine.
Why your 11 x 400 5 tire keeps going flat
It’s almost never a nail.
The biggest enemy of the 11 x 400 5 tire is bead leaks. Because these tires run at low PSI—usually between 12 and 22 pounds—the seal between the rubber and the metal rim is fragile. If the pressure drops too low over the winter, the bead pops off. Then you’re stuck in the garage with a compressor, trying to get the tire to "take a set" while air hisses out the sides.
Another culprit? Dry rot. Small tires have a high surface-area-to-volume ratio. They bake in the sun. If you see those tiny spiderweb cracks on the sidewall, the tire is dying. It might hold air today, but the first time you hit a bump, the casing might give up.
🔗 Read more: What Does a Stoner Mean? Why the Answer Is Changing in 2026
If you're dealing with a slow leak, don't just dump a whole bottle of green slime in there. It works for a while, but it corrodes the rims over time and makes a nightmare mess for whoever has to eventually change the tire. A better fix? Buy a tube. A $10 inner tube turns a leaky tubeless 11 x 400 5 tire into a reliable setup that will last another five years.
Installation is a nightmare (Do it anyway)
Changing a tire this small is surprisingly hard. You’d think a bigger tire would be tougher, but it’s the opposite. There's zero "give" in a 5-inch rim.
If you’re doing it yourself, use plenty of dish soap as a lubricant. It makes the rubber slide over the metal lip without tearing the bead. If you try to do it dry with a screwdriver, you're going to gouge the rim and ruin the new tire. Honestly, taking the wheel to a local lawnmower shop and paying them ten bucks to swap it on their machine is the best money you’ll ever spend. It saves your knuckles and your afternoon.
Essential maintenance for longevity
- Check the pressure monthly. Don't eyeball it. A tire that looks full can be at 5 PSI, which is low enough to break the bead on a turn.
- Store out of direct sunlight. UV rays eat these tires. If your mower sits outside, cover the tires or park it in the shade.
- Watch the bushings. Since many wheels using the 11 x 400 5 tire don't have ball bearings—they just have plastic or greaseable metal bushings—make sure you hit them with a grease gun. If the bushing wears out, the wheel wobbles, and the tire wears unevenly.
- Match your pairs. Never replace just one front tire if the other one is significantly worn. Your mower deck depends on both front tires being the exact same height to keep the cut level.
Making the right purchase
When you're ready to buy a new 11 x 400 5 tire, skip the generic listings that don't specify the ply rating. Look for brands with a history in turf like Carlisle, Martin, or Kenda. Make sure you check if the tire comes as "tire only" or as a "wheel assembly." Sometimes, buying the whole wheel with the bearings already pressed in is actually cheaper and way faster than struggling to mount a piece of stubborn rubber onto an old, rusty rim.
Actionable Steps for Your Equipment
- Check your sidewall right now: Confirm if you need a 2-ply or 4-ply based on your mower's weight.
- Inspect for "Cracking": If you see dry rot, order a replacement before the spring rush when prices spike and stock disappears.
- Level your deck: After installing a new 11 x 400 5 tire, park on a flat concrete surface and measure the distance from the blade tip to the ground on both sides. Don't assume the new tire is the exact same height as the old one.
- Grease the zerks: While the wheel is off or accessible, pump some high-quality lithium grease into the spindle. It’ll make your steering feel like new.
If you take care of the pressure and keep them out of the sun, a good set of tires in this size should easily last 500 to 700 hours of mowing time. It’s a small investment that keeps your lawn looking professional and your mower's front end from vibrating itself to pieces.