LT305/70R17 Tire Size

All You Need to Know About LT305/70R17 Tires

LT305/70R17 is a light-truck tire size built around a reinforced casing design and higher inflation capability. While its external dimensions match 305/70R17, which are ≈33.8 inches in overall diameter with an ≈8.4-inch sidewall, its behavior under load is defined by construction, not size alone.

In the LT305/70R17 size, the question is not whether the tire fits, but how it carries weight once installed. The LT designation changes how the tire resists deformation, how it responds to pressure, and how it performs under sustained load.

A sidewall of this height(8.4 inches) introduces leverage: under braking, cornering, or payload, the tire structure is asked to control a larger mass over a longer sidewall. LT construction counteracts that by increasing casing stiffness and allowing higher operating pressure, which reduces uncontrolled flex and stabilizes the contact patch.

LT305/70R17 Size Quick Specs

• Overall diameter: ≈33.8"
• Section width: 305 mm
• Sidewall height: ≈213.5 mm 
• Load Rating: typically 121/118 (3,195 lbs / 1,450 kg per tire)
• Rim width range: commonly ≈8.0"–10.0"
• Typical pressure capability: defined by load range and tire specification

How LT Construction Changes Behavior in This Size

On a tire approaching 34 inches in diameter, such as the LT305/70R17, structural control becomes a limiting factor. The larger the tire, the more sidewall movement occurs under the same load. LT construction reduces that movement by reinforcing internal plies and supporting higher inflation pressure.

This directly affects how the LT305/70R17 tire behaves in real use. Under towing or payload, reduced deflection improves directional stability and limits heat buildup. Under lighter loads, the same stiffness can make the ride feel firmer because less energy is absorbed through sidewall flex.

In other words, the LT designation in the LT305/70R17 size shifts the tire from a compliance-driven component toward a load-controlled one.

Pressure and Load Relationship in LT305/70R17

In LT305/70R17, load capacity is directly tied to inflation pressure within the limits defined by the tire’s load range. This size is commonly produced in Load Range C, D, and E configurations, each with a different maximum pressure and corresponding load capability.

Typical examples illustrate the spread:

• Load Range C versions operate around 50 psi with load capacities often in the ~2,600–2,800 lb range per tire
• Load Range D increases both pressure and capacity into the ~65 psi and ~3,000–3,200 lb range
• Load Range E versions extend up to ~80 psi and can support roughly ~3,500–3,800 lbs per tire, depending on the specific model.

Exact values vary by manufacturer and service description, so the tire’s sidewall markings remain the reference point.

On a tire with an ≈8.4-inch sidewall, pressure has a pronounced effect on how that load is carried. Lower pressure allows greater deflection across a larger sidewall height, increasing heat buildup and shifting load toward the shoulders. Higher pressure stabilizes the casing, reduces deformation, and keeps the contact patch more evenly supported under weight.

Because the sidewall is both tall and wide in the LT305/70R17 size, underinflation develops more gradually than on lower-profile tires. The tire can appear visually stable while internal stress increases over distance and load cycles. For LT305/70R17, correct pressure is not just a performance factor; it is what determines whether the tire is operating within its intended load capacity range.

Where LT305/70R17 Is Typically Used

The LT305/70R17 size is commonly selected for vehicles that combine increased tire diameter with real load demand, rather than purely visual or clearance-driven upgrades.

• Heavy-duty pickups (Ford Super Duty, Ram HD, Silverado HD)
• Half-ton trucks operating with towing or payload demands
• Overland builds carrying additional equipment
• Off-road vehicles requiring durability and sidewall resistance

In these scenarios, the LT305/70R17 size is chosen to manage load and stress over time, not simply to match a target diameter.

LT305/70R17 vs 305/70R17

• Dimensions: identical (≈33.8")
• Section width: identical (305 mm)
• Key difference: structural strength, pressure capability, and load response

Because both LT305/70R17 and 305/70R17 sizes share the same external dimensions, fitment outcomes are the same. The distinction appears only when the tire is put into use - particularly under load, where LT construction provides greater resistance to deformation and improved stability.

Recommeded LT305/70R17 Tires

All-terrain LT305/70R17 tires: Toyo Open Country A/T III

Rugged-terrain LT305/70R17 tires: Toyo Open Country R/T Pro

Affordable LT305/70R17 tires: Nitto Terra Grappler G3

LT305/70R17 Fitment Note

With LT305/70R17, matching the size is only the starting point. Load range, operating pressure, wheel compatibility, and actual vehicle demand must be aligned to ensure the tire performs as intended over time.