LT245/75R17 Tire Size

LT245/75R17 Tire Specs To Know Before Buying

LT245/75R17 uses a Light Truck (LT) construction designed for higher load capacity, reinforced casing strength, and operation under elevated inflation pressures compared to standard 245/75R17 tires.

Although LT245/75R17 shares the same external dimensions as 245/75R17 (≈31.5" diameter), its internal structure and pressure range define how it performs under load.

LT245/75R17 Size Specifications

• Overall diameter: ≈31.5"
• Width: 245 mm
• Sidewall height: 7.2"
• Rim width range: 6.5"–7.5"
• Measuring Rim Width: 7.0"

LT245/75R17 Load Range and Construction

LT245/75R17 is available in multiple load ranges, typically C, D, and E, each defining a different ceiling for inflation pressure and load capacity without changing the tire's external dimensions. Selecting the correct load range is not a matter of preference; it is a structural requirement determined by the vehicle's GVWR and intended use.

• LT245/75R17 C: Rated to around 50 psi, this tire suits lighter truck applications where occasional load-carrying is required but sustained heavy hauling or towing is not. The lower pressure ceiling allows more sidewall compliance, which can improve ride quality under lighter loads.
• LT245/75R17 D: Operating typically up to 65 psi, this tire adds ply strength and pressure capacity over the C version, making it appropriate for regular hauling and moderate towing duties where a stiffer, more controlled sidewall is needed.
• LT245/75R17 E: The most common heavy-duty choice, rated to 80 psi. At full inflation, Load Range E LT245/75R17 can support over 3,000 lbs per tire, making it the standard specification for vehicles that tow regularly, carry maximum payload, or operate under sustained highway stress.

LT245/75R17 vs Standard 245/75R17 Tires

LT245/75R17 and standard 245/75R17 share identical external dimensions - the same ≈31.5" overall diameter, 245mm width, and 17-inch wheel fitment. That match can make them look interchangeable, but construction type creates differences that size alone does not show.

• Dimensions: identical (≈31.5")
• Difference: load capacity and pressure limits
• Use case:  LT for towing, hauling, and operation near GVWR; standard for general driving within passenger-rated load limits

The reinforced LT in the LT245/75R17 casing resists deformation under sustained load; a 245/75R17 standard sidewall flexes more under equivalent weight, generating heat and reducing long-term stability

Because LT245/75R17 and standard 245/75R17 dimensions are identical, substitution depends entirely on load requirement. Fitting a standard 245/75R17 where LT construction is specified can result in insufficient capacity under towing or payload conditions, even though the size appears correct. The reverse - an LT where a standard is specified - is generally safe under load but will ride firmer due to the stiffer casing.

Comparison of LT245/75R17 With Close LT Sizes

Two sizes often compared with LT245/75R17 are LT245/70R17, which keeps the same section width but is shorter, and LT265/70R17, which is slightly wider but much closer in overall diameter. Based on overall diameter alone, only LT265/70R17 stays within the common ±3% substitution range.

LT245/75R17 vs LT245/70R17

• Width: both are 245 mm
• Overall diameter: LT245/70R17 is about 3.1% smaller, which places it just beyond the usual ±3% guideline

Because the shorter LT245/70R17 tire has a smaller rolling diameter, it turns more times per mile, which can cause the speedometer to read slightly high and alter effective gearing. In light-truck applications, that difference should not be treated as interchangeable without confirming load capacity, inflation requirements, and vehicle-specific fitment.

LT245/75R17 vs LT265/70R17

• Width: LT265/70R17 is 20 mm wider
• Overall diameter: the difference is only about 0.4%, which is well within the usual diameter tolerance

From a diameter standpoint, LT265/70R17 is the closest substitute to LT245/75R17. The main change is not height, but width: the tire sits wider, which can affect clearance to suspension components, the wheel well, and the approved rim-width range. Before using it, confirm wheel-width compatibility, clearance at full lock and compression, and that the replacement tire’s load index and load range meet or exceed the vehicle requirement.