Switching from 35-inch to 37-inch tires increases your vehicle's overall height by approximately 2 inches, which translates to about 1 inch of additional ground clearance. This change impacts fitment, performance, and aesthetics, requiring careful planning.
The primary difference is in the tire's overall diameter. While the names suggest a 2-inch difference, the actual measured height can vary between brands and models. For instance, a popular 35x12.50R17 tire might measure 34.5 inches, while a 37x12.50R17 could be 36.5 inches. The key is the radius—the distance from the wheel center to the ground. A 2-inch larger diameter means a 1-inch larger radius, lifting the axle and raising ground clearance by that amount.
| Consideration | 35" Tire | 37" Tire | Net Change |
|---|
| Overall Diameter | ~34.5" - 35.5" | ~36.5" - 37.5" | +~2 inches |
| Approx. Ground Clearance Gain | Baseline | Comparison | +~1 inch |
| Common Weight (per tire) | 65-75 lbs | 75-85 lbs | +10-20 lbs |
This physical increase creates fitment challenges. Most vehicles need modifications to prevent the tires from rubbing against fenders, liners, or suspension components during turns or over bumps. This often involves installing a lift kit—typically 2-3 inches for a clean fit—along with potential trimming of body panels. Market data from major off-road shops indicates that over 70% of trucks moving to 37s require at least some level of fender modification.
Performance is noticeably affected. The larger, heavier tires increase rotational mass, placing more stress on axles, wheel bearings, and differentials. You will experience a reduction in fuel economy and slower acceleration, as the engine works harder to turn the tires. Many find that changing the differential gear ratio (re-gearing) is necessary to restore lost torque and drivability, especially in trucks with smaller engines. The added weight can also lead to faster wear of stock brake components.
Visually, 37-inch tires fill the wheel wells more completely, giving trucks and SUVs a more aggressive, purpose-built stance. However, the functional benefits for serious off-roading are significant: that extra inch of clearance can be the difference between scraping over an obstacle or clearing it cleanly, protecting vital undercarriage components.
