TRA E-4, complete reference

The Pilbara haul truck workhorse.

E-4 is the Tire and Rim Association (TRA) service code for haul truck and earthmover tyres with extra-deep tread, typically 1.5 times the depth of an E-3 in the equivalent size. The deeper tread translates to longer service life under abrasive conditions, better cut resistance, and more retread potential at end-of-life.

The E-4 is the standard fitment on most tier-one Pilbara iron ore haul fleet, Caterpillar 793F, 797F, Komatsu 830E, 930E, Liebherr T 264. The lifecycle economics favour E-4 over E-3 on long-cycle, high-tonnage haul operations even though the unit cost is higher: longer life, more retreads, lower cost-per-tonne hauled.

Where E-4 sits in the E-series

• E-3 Rock Regular: standard tread depth, normal-duty rock haul. Mid-size haul trucks (90-150t). Tread depth approximately 64-72 mm in 33.00R51.
• E-4 Rock Deep: extra-deep tread, longer life, cut resistance. Tier-one Pilbara iron ore haul (200-240t). Tread depth approximately 92-108 mm in 40.00R57.
• E-5 Rock Extra Deep: maximum tread depth. Extreme applications, uncommon.

Common E-4 sizes

The E-4 service code appears in sizes including:

• 27.00R49, CAT 777F, Komatsu HD785 class (90-100t haul)
• 33.00R51, CAT 785D, Komatsu HD1500 class (130-150t)
• 37.00R57, Some 180t class haul applications
• 40.00R57, CAT 793F, Komatsu 830E (~218t)
• 46/90R57, 50/80R57, Newer-generation Pilbara fitments
• 53/80R63, 59/80R63, Giant haul (CAT 797F, Komatsu 930E)

Brand patterns in E-4

• Bridgestone: VRPS, VRLS, VHS, V-Steel, across the E-4 size range
• Michelin: XDR, XDR3, XDR4, premium E-4 line
• Goodyear: RM-4A+, RM-4B+, RH-4A, E-4 alternatives across sizes
• Yokohama: Y69, RB42, strong cost-to-tier-one in E-4
• BKT: Earthmax SR45, mid-tier E-4 option
• Aeolus: AE57, wide availability through trader channels

When E-4 makes sense vs E-3

The E-4 cost premium over E-3 in the same size is typically 15-25%. The service life gain is typically 35-50% in abrasive conditions. The lifecycle economics favour E-4 in:

• Iron ore haul (abrasive material, long cycles)
• Hard-rock mining
• Long-distance haul where cycle wear dominates failure mode
• Operations where retreadable casing residual value is captured

E-3 retains its place in:

• Short-cycle haul (where cut damage dominates over tread wear)
• Soft-material haul (coal, gypsum, lower-abrasion material)
• Smaller haul trucks where E-4 isn't manufactured in the size
• Operations without retread infrastructure