LT38X12.50R17 Tire Size

LT38X12.50R17 Tires: What This 38-Inch Light Truck Size Means

LT38X12.50R17 is a 38-inch flotation tire - three full inches taller than a 35-inch tire - designed for heavily modified trucks and dedicated off-road builds where maximum ground clearance is the primary goal.

The LT prefix in the LT38X12.50R17 size confirms Light Truck construction and load standards. Tires in this size typically carry a Load Range C or D rating. Note that LT38X12.50R17 is a specialty size with limited manufacturer availability; buyers should verify current in-stock options before planning a build around this size.

LT38X12.50R17 Quick Specs

What Each Part of the LT38X12.50R17 Size Means

• LT - Light Truck designation
• 38 - Overall tire diameter in inches
• 12.50 - Approximate section width in inches
• R - Radial construction
• 17 - Wheel diameter in inches

LT38X12.50R17 vs LT35X12.50R17: What Three Inches Actually Means

The section width is identical between LT38X12.50R17 and LT35X12.50R17. Running LT38X12.50R17 instead of LT35X12.50R17 produces cascading effects across the vehicle:

• Ground clearance increases by approximately 1.5 inches (the radius gain)
• Speedometer and odometer read low without recalibration - the taller tire covers more ground per revolution
• The effective gear ratio becomes numerically lower, reducing low-end torque and acceleration unless re-gearing is performed
• Driveline stress increases, often requiring axle and differential upgrades
• Fuel economy typically decreases

For rock-crawling and trail use where clearance is paramount, this tradeoff is acceptable. For a daily-driven street truck, the penalty is significant.

Where LT38X12.50R17 Tires Are Commonly Used

• Rock-crawling competition vehicles
• Custom lifted trucks (typically 6"+ lift required)
• Extreme off-road builds and trail rigs
• Trail-focused Jeep Wrangler builds
• Heavy-duty off-road applications with upgraded axles

Do LT38X12.50R17 Tires Require Major Modifications?

Yes. Most vehicles require substantial suspension modifications for LT38X12.50R17 tires (typically a 4"-6" or larger lift), axle and differential upgrades, re-gearing to restore power delivery, and body or fender trimming for full clearance. This is not a bolt-on size for stock or mildly modified vehicles.