Tire Size Guide
Last Updated: March 2026
Understanding tire sizes is essential for choosing the right tires for your commercial truck. This guide breaks down how to read tire markings on the sidewall and helps you find the correct size for your vehicle.
1. How to Read a Commercial Tire Size
Commercial truck tire sizes follow a standardized format. Let's break down the most common size: 295/75R22.5
- 295 — Section width in millimeters (the tire's width from sidewall to sidewall)
- 75 — Aspect ratio (sidewall height is 75% of the section width)
- R — Radial construction (virtually all modern truck tires are radial)
- 22.5 — Rim diameter in inches
For sizes like 11R22.5, the format is slightly different:
- 11 — Section width in inches (≈ 279mm)
- R — Radial construction
- 22.5 — Rim diameter in inches
- No aspect ratio listed = standard aspect ratio (approximately 90-92%)
2. Understanding the DOT Code
The DOT (Department of Transportation) code is printed on every tire's sidewall and contains critical information:
Example: DOT XXXX XXXX 2425
- The last 4 digits indicate the manufacturing date
- 24 = 24th week of the year
- 25 = year 2025
- So "2425" means the tire was manufactured in June 2025
Why it matters: Tires degrade over time regardless of use. We recommend professional inspection for tires over 5 years from manufacture date, and replacement for tires over 10 years old.
3. Load Index & Speed Rating
After the tire size, you'll see numbers and letters indicating load capacity and speed rating:
Example: 295/75R22.5 144/141L
- 144/141 — Load index (single/dual configuration). 144 = 6,175 lbs per tire (single), 141 = 5,675 lbs per tire (dual)
- L — Speed rating (L = 75 mph maximum). Common ratings for truck tires: L (75 mph), M (81 mph)
Critical: Never install a tire with a lower load index than specified by your vehicle manufacturer. Overloading causes premature tire failure, which is dangerous and voids the warranty.
4. Tire Pressure (PSI)
Correct inflation is the single most important factor in tire life and safety. The maximum cold inflation pressure is printed on the tire sidewall.
Typical pressures for commercial truck tires:
- Steer tires: 110–120 PSI
- Drive tires: 95–110 PSI
- Trailer tires: 100–110 PSI
Important:
- Always check pressure when tires are cold (before driving or after sitting 3+ hours)
- Under-inflation causes excessive heat, shoulder wear, and increased blowout risk
- Over-inflation causes center tread wear and reduced traction
- Check pressure at least weekly for commercial vehicles
Not sure which size you need? Call us at (224) 642-8165 — our team will help you find the right fit for your truck and application.
Common Tire Sizes We Carry
Click any size below to browse our inventory.
295/75R22.5
Available in: Steer, Drive, Trailer
The industry standard for Class 8 semi-trucks. Fits most Freightliner Cascadia, Peterbilt 579, Kenworth T680, Volvo VNL, and International LT.
- Section width: 295mm (11.6 inches)
- Rim size: 22.5 inches
- Load range: H (16-ply rated)
- Our price range: $210–$310
11R22.5
Available in: Steer, Drive, Trailer
The traditional inch-based sizing used on most Class 7 and Class 8 trucks. Interchangeable with 295/75R22.5 on 22.5" rims. Popular on older Freightliner, Mack, and International trucks.
- Section width: 11 inches (279mm)
- Rim size: 22.5 inches
- Load range: H (16-ply rated)
- Our price range: $230–$330
11R24.5
Available in: Steer, Drive
The larger 24.5" rim option for trucks spec'd with this wheel size. Common on some Peterbilt, Kenworth, and Western Star models.
- Section width: 11 inches (279mm)
- Rim size: 24.5 inches
- Load range: H (16-ply rated)
- Our price range: $250–$330
285/75R24.5
Available in: Drive
Metric equivalent for the 24.5" rim platform. Used on trucks with 24.5" rims where a slightly narrower profile is preferred.
- Section width: 285mm (11.2 inches)
- Rim size: 24.5 inches
- Our price range: $240–$280
225/70R19.5 & 215/75R17.5
Available in: Steer, Drive
For Class 4–6 medium-duty trucks — box trucks, delivery vans, flatbeds, and dump trucks. Fits Freightliner M2, International MV/CV, Hino, Isuzu NPR/NRR.
- 19.5" and 17.5" rim platforms
- Lower load ratings suited to medium-duty applications
- Our price range: $120–$170
ST235/80R16 & LT245/75R17
Available in: Trailer (ST), All-Position (LT)
For pickup trucks, utility trailers, and flatbed trailers. ST (Special Trailer) tires are designed specifically for trailer use — never use on a powered axle.
- ST = Special Trailer (trailer only)
- LT = Light Truck (all positions)
- Our price range: $115–$140
Tire Size FAQ
Yes, in most cases. Both sizes fit 22.5" rims and have very similar dimensions (295mm ≈ 11.6"). However, always verify the load index meets or exceeds your vehicle's requirements, and don't mix sizes on the same axle.
Check three places: (1) The tire placard on the driver's door jamb or glove box, (2) Your vehicle owner's manual, or (3) The current tires on your truck (look at the sidewall markings). You can also call us at (224) 642-8165 with your truck's year, make, model, and axle configuration — we'll look it up for you.
We strongly recommend sticking to the manufacturer's specified size. Different sizes affect speedometer accuracy, ABS calibration, clearance, and may void your vehicle warranty. If you're considering a size change, consult your truck dealer or call us to discuss.
Load Range indicates the tire's ply rating and maximum load capacity. For commercial trucks: Load Range G = 14-ply rated, Load Range H = 16-ply rated (most common for Class 8), Load Range J = 18-ply rated. Higher load range = higher weight capacity but also a stiffer ride.