Tire Load Index vs. TPMS & Valve Stems
Comparing 2 standards across 13 specifications. 13 key differences identified.
The Tire Load Index (standardized under ISO 4000-1) is a numerical code assigned to a passenger or commercial tire indicating the maximum physical weight (in kilograms and pounds) the tire can carry when inflated to its maximum operating cold tire pressure. Spanning Load Index 70 (335 kg / 739 lb) to Load Index 120 (1400 kg / 3086 lb) per tire.
Tire Pressure Monitoring Systems (TPMS, mandated by the US TREAD Act and EU UNECE Regulation 64) utilize Direct TPMS wheel-mounted valve sensors communicating via RF radio frequencies (315 MHz in North America, 433.92 MHz in Europe and Global). Utilizing the standard Schrader pneumatic valve with unified 8V1-32 UNEF cap threads.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standardization
|
ISO 4000-1 / ETRTO / TRA Load Tables | — |
|
Standard Load (SL) Pressure
|
Calibrated at 2.5 bar (36 psi) cold inflation pressure for passenger car tires | — |
|
Extra Load (XL / Reinforced)
|
Reinforced internal carcass calibrated at 2.9 bar (42 psi) for heavy electric vehicles (EVs) and SUVs | — |
|
Common Passenger Load Indices
|
LI 82: 475 kg (1,047 lb) | LI 88: 560 kg (1,235 lb) | LI 91: 615 kg (1,356 lb) | LI 95: 690 kg (1,521 lb) | — |
|
Heavy EV & SUV Load Indices
|
LI 100: 800 kg (1,764 lb) | LI 104: 900 kg (1,984 lb) | LI 108: 1,000 kg (2,205 lb) | LI 112: 1,120 kg (2,469 lb) | — |
|
Vehicle Axle Calculation
|
Sum of two tire load capacities on an axle must exceed the Gross Axle Weight Rating (GAWR) | — |
|
HL (High Load) EV Benchmark
|
New standard for heavy battery packs carrying higher load at equivalent tire volume and pressure | — |
|
Pneumatic Valve Standard
|
— | Schrader automotive tire valve (standard TR413 / TR414 rubber snap-in or metal clamp-in) |
|
Valve Thread Specification
|
— | 8V1-32 UNEF (0.305 in / 7.7 mm diameter with 32 threads per inch) |
|
North American TPMS Frequency
|
— | 315 MHz UHF radio frequency (FCC Part 15 compliant) |
|
European & Global TPMS Frequency
|
— | 433.92 MHz UHF radio frequency |
|
Direct vs Indirect TPMS
|
— | Direct: Physical pressure sensor in each wheel | Indirect: ABS/ESP wheel speed sensors calculate rolling circumference drops |
|
TPMS Warning Threshold
|
— | Mandated dash warning triggers when pressure drops 25% below the placard recommended cold pressure |