Tire Width 165 vs 175: Performance and Fit

What the numbers mean

In a tire size like 165/70R14 or 175/65R14, the first number is the nominal section width in millimeters. Section width is the linear distance between the exteriors of the sidewalls of an inflated tire, excluding ribs, labels, or protective bands. A 175 tire is therefore nominally 10 mm wider across the sidewalls than a 165 tire, though actual measured width varies with the rim width and the tire's design.

The second number is the aspect ratio, a percentage of the section width. A 175/65R14 has a sidewall height of about 114 mm, while a 165/70R14 has a sidewall height of about 116 mm. Because the aspect ratio changes, switching widths often requires rechecking the overall diameter and speedometer accuracy. See tire aspect ratio and tire section width for more detail.

Grip and handling differences

A wider tire generally provides a larger contact patch, all else equal. That extra rubber on the road can improve cornering grip and braking traction, especially in dry conditions. In practice, moving from 165 to 175 is a modest step: you gain roughly 6 percent in section width, so the grip increase is noticeable but not dramatic.

On wet roads, a wider tire can also help by spreading the load, but it may be more prone to hydroplaning at higher speeds because it has to displace more water. The tread pattern and compound matter more than width alone. If you are choosing between the two for a daily commuter, the width difference is less important than the tire's wet-weather design. Our best all-season tires guide covers options in both widths.

Rolling resistance and fuel economy

Rolling resistance is the energy lost as a tire deforms while rolling. A narrower tire typically has lower rolling resistance, which can translate into slightly better fuel economy. The exact difference between 165 and 175 depends on the tire construction, tread compound, and inflation pressure, but the trend is consistent: wider tires costs a little efficiency.

Proper inflation has a much larger effect than width alone. Keeping tires inflated to the vehicle manufacturer's recommended cold pressure can improve gas mileage by 0.6 percent on average, and up to 3 percent in some cases. Under-inflated tires can lower gas mileage by about 0.2 percent for every 1 psi drop in the average pressure of all tires. See tire pressure basics and tire width and fuel economy for guidance.

Wheel fitment and clearance

The most critical difference between 165 and 175 tires is whether they fit your wheels and your car. Each tire size is designed to mount on a specific rim width range. A 175 tire generally requires a rim that is about 0.5 inch wider than what a 165 uses, though ranges overlap. Using a tire on a rim that is too narrow or too wide can degrade handling, cause premature wear, and create a safety risk.

Before switching, check the rim width marked on your wheels and the tire's recommended rim width range. Also consider clearance: a 175 tire is wider across the sidewalls, so it may rub against the strut, fender liner, or suspension components, especially when turning or carrying a load. The vehicle's tire placard and owner's manual list the original tire size and the recommended replacement sizes. See our tire rim width range for details.

Load capacity and speed rating

Width is not directly related to load capacity; the load index and inflation pressure determine how much weight a tire can carry. A 175 tire in the same load range may have a similar or slightly higher load rating than a 165, but you must verify the load index on the sidewall. Federal standards require that the vehicle's maximum load on each tire not exceed the tire's maximum load rating.

The speed rating is also independent of width. If you switch from 165 to 175, keep the same speed rating or go higher, especially for highway driving. Our tire speed rating guide and tire load index rating explain these markings.

Ride comfort and noise

A wider tire with the same aspect ratio may transmit more road harshness because it has a shorter sidewall for a given diameter, but when the aspect ratio changes, the effect is mixed. As noted, a 175/65R14 has a slightly shorter sidewall than a 165/70R14, so it can feel a bit firmer. If ride comfort is a priority, you might prefer the 165 or a tire with a taller sidewall.

Tire noise is influenced more by tread pattern and construction than by width. A 175 tire may generate slightly more noise on coarse pavement, but the difference is small. For a quieter ride, look for a tire with a symmetric or low-noise tread design.

What to pick for your driving

For most drivers of small cars, subcompacts, and older compacts that came with 165s, sticking with the original size is the safest choice. The 165 offers slightly better fuel economy, adequate grip for everyday driving, and guaranteed fitment. If you want a bit more cornering grip and your wheels and suspension have clearance, a 175 is a reasonable upgrade, but only after confirming the rim width range and checking for rubbing.

Drivers who carry heavy loads or tow should verify that the 175 tire's load index meets or exceeds the original. For winter driving, a narrower tire often performs better in snow because it concentrates the vehicle's weight on a smaller footprint. See tire width for snow for more. If you are shopping, our best 175/65R14 tires and best 175/70R14 tires guides list options by specs.

What to pick for your use

Questions

Can I replace 165 tires with 175 tires on the same rims?

Only if the rim width falls within the range recommended for the 175 tire. Check the rim width stamped on the wheel and the tire's specification. Also confirm that the wider tire clears the strut, fender, and suspension. When in doubt, consult a tire professional.

Will 175 tires improve handling?

A 175 tire usually has a slightly larger contact patch, which can improve cornering grip in dry conditions. The improvement is modest. The tire's tread compound and construction matter more than the 10 mm width difference.

Do 175 tires reduce fuel economy?

A wider tire generally has higher rolling resistance, so it can trim fuel economy slightly compared with a 165. The effect is small. Proper inflation has a much larger impact than the width difference.

What is the difference in section width between 165 and 175?

The nominal section width is 10 mm wider for a 175 tire. Actual measured width varies with rim width and tire design.

Can I mix 165 and 175 tires on the same axle?

No. Tires on the same axle should be the same size, construction, and tread pattern. Mixing widths can cause erratic handling and stress the drivetrain. Replace tires in pairs at minimum.

Is a 175 tire better in snow than a 165?

Often not. A narrower tire concentrates the vehicle's weight onto a smaller footprint, which can improve snow traction. Many winter drivers prefer the narrower width.