Tire Size 305/70r16 vs 315/75r16
The main difference between 305/70r16 and 315/75r16 tires is their diameter. The 315/75r16 tires are 1.79 inches (45.5 mm) larger in diameter than the 305/70r16 tires.
That means 315/75r16 is better suited for off-road driving and provides more ground clearance.
305/70r16 vs 315/75r16
This table will allow you to quickly and easily comprehend the distinctions between the options.
The 315/75r16 tire has a 5.5% larger diameter and 3.3% wider width compared to the 305/70r16.
This crosses the 3% replacement tire barrier, meaning the 315 may require modifications like a lift kit to prevent rubbing at full turn. The smaller 305 tire is a more direct replacement.
With a diameter of 34.6 inches, the 315/75r16 provides 1.79 inches more ground clearance than the 305/70r16 at 32.81 inches.
This added clearance is excellent for off-roading, helping avoid scrapes. However, the larger diameter causes a lower speedometer reading on the 315 tire.
The 315/75r16 larger size and heavier weight will likely reduce fuel efficiency compared to the 305/70r16.
The smaller 305 has less rolling resistance and rotational mass, contributing to better gas mileage.
The taller sidewall and greater air volume of the 315/75r16 absorb bumps and impact better, providing a smoother ride over uneven terrain.
The 305/70r16 transmits more road vibration but offers a comfier highway ride.
The 315 has a stretched, aggressive look due to the taller sidewall, suiting trucks and SUVs. The 305 has a lower profile appearance that some prefer aesthetically. Neither is drastically different visually.
Handling & Stability
The 305 shorter sidewall and smaller size give it quicker steering response and handling precision.
The 315 taller sidewall flexes more, reducing handling sharpness slightly but aiding stability off-road.
Noise & Vibration
The 315 dampens road noise and vibration better with its extra sidewall flex and air volume. The shorter 305 sidewall transmits more harshness into the cabin over bumps.
Durability & Wear
The smaller 305 tire exhibits potentially longer tread life and even wear. The larger 315 sees more stress, which could increase wear on components.
The narrower 305 can cut through the snow for better traction. The wider, taller 315 provides an advantage in deep mud or sand with its larger footprint. Both perform well overall in adverse conditions.
At 20 mph true speed, the 305 reads 20 mph on the speedometer. The larger diameter 315 reads 21.09 mph at that true speed, a difference of 1.09 mph.
What Does 305/70r16 Tire Mean?
The number and the letter in a tire’s size designation tell you the tire’s width in millimeters and inches, respectively.
The “R” stands for radial construction, and the 16 is the diameter of the wheel in inches. So, a 305 70r16 tire has a width of 12.01 inches or 305 millimeters and a diameter of 16 inches.
Based on the comparisons, the 315/75r16 is better suited for off-road driving and adventures due to its larger diameter, added ground clearance, and improved traction in mud or sand.
However, the 305/70r16 rates better for on-road performance with its responsive handling, smoother highway ride, and increased fuel efficiency from less rolling resistance.
For daily driver or street performance, we recommend the 305/70r16 for its optimized on-road capabilities. But the 315/75r16 is the better choice for off-road activities for tackling rough terrain.
Meet Caitlin McCormack, a Tire Size Expert and Blogger Passionate About Everything Related to Tires. With Years of Experience in the Tire Industry, Caitlin Has Become an Expert in Tire Sizes and Their Impact on Vehicle Performance.