Carlisle Straight Rib Lawn & Garden Tire - 18X9.50-8

What It Is

The Carlisle Straight Rib Lawn & Garden Tire (18x9.50-8) is a smooth-rolling, low-aggression tire designed for the front axle of zero-turn mowers, lawn tractors, and garden tractors. Its straight-rib tread minimizes scuffing on turf while providing stable steering response.

Fitment & Compatibility

• Size: Must be 18 inches tall, 9.50 inches wide, and fit an 8-inch diameter rim. Measure your current tire’s sidewall markings to confirm.
• Rim width: Designed for 7- to 8-inch wide rims. Check your rim’s stamped width before mounting.
• Load capacity: Rated for up to 575 lbs per tire at 24 PSI. Ensure your machine’s front axle weight doesn’t exceed this.
• Common brands/models: Fits many John Deere, Husqvarna, Cub Cadet, and Toro zero-turns (e.g., Z400, Z500 series). Not a direct OEM replacement for all models—compare tread pattern and offset (3+3 or 4+4 rib patterns vary).
• OEM vs aftermarket: Aftermarket upgrade; verify your original tire size and rim offset (measured from mounting face to rim center). If your OEM tire is a different tread style (e.g., turf saver), handling may change.

Key Things to Know

• Quality: Carlisle is a trusted brand; 4.7/5 rating from 2,413 reviews confirms durability and even wear under normal use.
• Installation: Moderate difficulty—requires tire irons, bead sealer, and an air compressor. Tubeless design, but use a rim sealant if mounting on rusty rims.
• Common gotcha: Straight-rib tires provide less traction on wet grass or loose soil than multi-rib or knobby tires. Avoid if you mow steep slopes or damp turf regularly.
• Pressure: Under-inflating (below 20 PSI) can cause cupping; over-inflating (above 28 PSI) reduces traction. Stick to 22–26 PSI for most zero-turns.

Should You Buy It

Yes, if you need a durable, low-scuff front tire for a zero-turn or lawn tractor on flat, dry turf. Skip it if you frequently mow wet grass, soft soil, or slopes—choose a multi-rib or turf-saver pattern instead for better grip.