📋 Guide Contents
1. Military Tire Sizing Explained
What do military tire size numbers mean?
Military tire sizes use a specific format to indicate dimensions. For example, in size 37x12.50R16.5:
- 37 = tire height (diameter) in inches
- 12.50 = tire width in inches
- R = radial construction
- 16.5 = wheel (rim) diameter in inches
How to read military tire sizes step-by-step:
Common Military Tire Size Format: 37x12.50R16.5
- 37 = Overall tire diameter in inches (37 inches tall)
- 12.50 = Section width in inches (12.5 inches wide)
- R = Radial construction
- 16.5 = Rim diameter in inches
Metric Military Sizes: 395/85R20
- 395 = Section width in millimeters
- 85 = Aspect ratio (sidewall height as % of width)
- R = Radial construction
- 20 = Rim diameter in inches
Pro Tip
Military tires often use unique rim sizes like 16.5" and 20" that are different from common civilian sizes. Make sure your wheels are compatible before purchasing.
2. Civilian to Military Conversion Chart
Popular Military Tire Conversions
Use this chart to find equivalent civilian tire sizes for comparison:
| Military Size | Approximate Civilian Equivalent | Diameter (inches) | Width (inches) | Common Applications |
|---|---|---|---|---|
| 37x12.50R16.5 | 315/75R16 | 37" | 12.5" | HMMWV, Hummer H1 |
| 395/85R20 | 46x15.5R20 | 46" | 15.5" | MRAP, 6x6 Trucks |
| 1400R20 | Not Available | 48" | 14" | Heavy Military Trucks |
| 1600R20 | Not Available | 53" | 17.2" | Large Military Vehicles |
| 12.00R20 | 305/85R20 | 44" | 12" | Medium Tactical Vehicles |
Conversion Note
These are approximate conversions for comparison purposes. Military tire construction typically offers higher load capacity and durability than civilian equivalents.
3. Load Ratings & Ply Information
Understanding Load Range Classifications
Military tires use heavy-duty construction with higher load capacities than civilian tires:
| Load Range | Ply Rating | Max PSI | Construction | Typical Applications |
|---|---|---|---|---|
| D | 8 Ply | 65-80 PSI | Heavy Duty | Light Military Vehicles |
| E | 10 Ply | 80-95 PSI | Extra Heavy Duty | HMMWV, Medium Trucks |
| G | 14 Ply | 110-120 PSI | Super Heavy Duty | MRAP, Large Tactical Vehicles |
| J | 18 Ply | 125-150 PSI | Ultra Heavy Duty | Heavy Military Trucks |
| M | 22+ Ply | 150+ PSI | Maximum Duty | Largest Military Vehicles |
Load Capacity Benefits
Military tire construction provides exceptional load capacity and durability, making them excellent for heavy-duty civilian applications like agriculture, construction, and off-road recreation.
4. Reading DOT Date Codes
How to Determine Tire Age
All DOT-approved tires have manufacture date codes. Here's how to read them:
DOT Code Format
Example: DOT ABCD EFG 2318
- DOT = Department of Transportation approval
- ABCD EFG = Plant and size code
- 2318 = Date code (Week 23 of 2018)
Date Code Breakdown
- First two digits (23) = Week of manufacture (23rd week)
- Last two digits (18) = Year of manufacture (2018)
Tire Age Guidelines
| Tire Age | Condition | Typical Applications | Considerations |
|---|---|---|---|
| 0-6 Years | Excellent | All Applications | Peak performance period |
| 6-10 Years | Good | Most Applications | Widely used in military surplus market |
| 10+ Years | Variable | Off-road, Agricultural, Industrial | Condition depends on storage and care |
Military Surplus Tire Quality
Military surplus tires often have excellent remaining tread life due to limited use and proper military storage. Age should be considered alongside tread condition and your intended application.
5. HMMWV Tire Fitment Guide
Standard HMMWV Tire Specifications
The High Mobility Multipurpose Wheeled Vehicle (HMMWV/Humvee) uses specific tire and wheel combinations:
Original Equipment Specifications
- Tire Size: 37x12.50R16.5
- Load Range: D (8-ply) or E (10-ply)
- Rim Size: 16.5" x 8.25"
- Bolt Pattern: 12 bolts (unique pattern)
- Operating Pressure: 15-35 PSI (depending on load/terrain)
Compatible Tire Brands & Models
- Goodyear Wrangler MT - All-terrain military tread
- Goodyear Wrangler MTR - Enhanced off-road traction
- BF Goodrich Baja - Desert and off-road performance
- MICHELIN XZL (rare in 37x12.50R16.5 size)
Civilian Vehicle Compatibility
HMMWV tires can fit these civilian vehicles with modifications:
- Hummer H1 - Direct fitment (same vehicle platform)
- Chevy/GMC 2500/3500 - With wheel adapters
- Ford F-250/350 - With wheel adapters
- Dodge Ram 2500/3500 - With wheel adapters
HMMWV Wheel Advantage
HMMWV wheels are designed for extreme off-road use with reinforced construction and run-flat capability. They're excellent for serious off-road applications.
Wheel Adapter Installation
When using wheel adapters, follow manufacturer torque specifications and maintain proper installation procedures for optimal performance.
6. Installation & Safety Guidelines
Pre-Installation Inspection
Before installing military surplus tires, conduct a thorough inspection:
- Tread Inspection: Check for even wear, adequate depth (minimum 4/32")
- Sidewall Examination: Look for cracks, bulges, or weather damage
- DOT Code Verification: Confirm age and manufacturing date
- Internal Inspection: Check for separation or internal damage
- Rim Compatibility: Verify proper size match
Installation Requirements
- Professional Installation Recommended: Military tires require proper mounting techniques
- Balancing: Essential for road use and tire longevity
- Proper Torque: Follow manufacturer specifications for lug nuts
- Pressure Setting: Adjust based on load and application
Special Considerations for Military Tires
- Heavy Weight: Military tires are significantly heavier than civilian tires
- Stiff Sidewalls: May require higher mounting pressures
- Tube vs. Tubeless: Some military tires require inner tubes
- Run-Flat Capability: Many military tires can operate with low/no pressure
Professional Installation
Military tires require proper mounting techniques due to their heavy-duty construction. Professional installation ensures optimal performance and safety.
Tools & Equipment Needed
- Heavy-duty tire machine (civilian machines may struggle)
- High-pressure air compressor
- Torque wrench
- Tire pressure gauge
- Safety equipment (safety glasses, steel-toed boots)
7. Legal Considerations for Road Use
DOT Approval Status
Most military surplus tires are DOT-approved and legal for road use when:
- Tread depth meets minimum requirements (typically 2/32" minimum)
- No visible damage or defects
- Proper size for vehicle weight rating
- Age appropriate for intended use
State and Local Regulations
Check your local regulations for:
- Tread Depth Requirements: Varies by state (2/32" to 4/32")
- Tire Age Limits: Some states have age restrictions
- Load Capacity: Must meet or exceed vehicle requirements
- Size Restrictions: Some areas limit tire size projections
Commercial Use Considerations
For commercial vehicles:
- DOT inspections may have stricter requirements
- Age limits may be more restrictive
- Load ratings must match vehicle specifications
- Retread restrictions may apply
Off-Road vs. Road Use
Many buyers prefer military surplus tires for off-road recreation, agriculture, or industrial applications where road legality is less critical but durability is essential.
Insurance Considerations
- Inform insurance company of tire modifications
- Ensure coverage includes non-standard tire sizes
- Document proper installation and maintenance
- Keep purchase receipts and specifications
8. Maintenance & Care Tips
Pressure Management
Proper pressure is critical for military tire performance:
- Check Weekly: Military tires can lose pressure gradually
- Adjust for Load: Increase pressure for heavy loads
- Temperature Considerations: Pressure changes with temperature
- Use Quality Gauge: Military tires require accurate measurement
Regular Inspection Schedule
- Weekly: Visual inspection and pressure check
- Monthly: Detailed tread and sidewall examination
- Quarterly: Professional inspection if used on road
- Annually: Complete assessment including interior inspection
Storage Best Practices
For stored military tires:
- Cool, Dry Location: Avoid extreme temperatures
- UV Protection: Keep out of direct sunlight
- Proper Support: Store mounted tires vertically
- Pest Control: Protect from rodents and insects
Extending Tire Life
- Rotation: Regular rotation for even wear
- Alignment: Proper vehicle alignment prevents premature wear
- Avoid Overloading: Stay within load capacity limits
- Smooth Operations: Avoid sudden acceleration/braking
Military Tire Longevity
Well-maintained military surplus tires can provide years of service. Their heavy construction often outlasts civilian tires in demanding applications.
Common Issues and Solutions
| Issue | Possible Causes | Solutions | Prevention |
|---|---|---|---|
| Uneven Wear | Poor alignment, incorrect pressure | Professional alignment, pressure adjustment | Regular maintenance checks |
| Cracking | Age, UV exposure, temperature | Replacement if severe | Proper storage, UV protection |
| Pressure Loss | Valve stems, rim seal, age | Professional inspection | Regular pressure monitoring |
| Vibration | Imbalance, separation | Rebalancing, professional check | Proper installation, regular inspection |