245/75R16 Vs 265/75R16 Tire: What’s the Difference?

One can change their tires or wheels for different reasons. Yet, switching tires without any calculation is never recommended. Doing this can be hazardous.

If you want to know whether 245/75R16 and 265/75R16 tires are interchangeable, you need to do your math. It may seem quite tricky. No problem! We are here to do the math on your behalf.

As you read further, you will learn the fundamental difference between the two tires. You will also find a chart on 245/75R16 vs. 265/75R16 Tire.

245/75R16 Vs 265/75R16 Tire: Comparison Table

Here’s a quick sum-up of the comparison between the two tires. However minor the differences may be, these are what sets them apart.

245/75R16 TireType265/75R16 Tire
30.47 inches / 773.9 mmDiameter Difference 1.18 (30) 3.9% inches (mm)31.65 inches / 803.9 mm
9.65 inches 245 mmWidth Difference 0.79 (20) 8.2% inches (mm)10.43 inches 265 mm
95.72 inches or 2431.28 mmCircumference Difference 3.71 (94.25) 3.9% inches (mm)99.43 inches or 2525.53 mm
7.23 inches or 183.75 mmSidewall Height difference 0.59 (15) 8.2% inches (mm)7.82 inches or 198.75 mm
661.93 rpm or 411.31 kmRevolutions per mile difference -24.7 (-15.35) -3.7% rpm (km)637.23 rpm or 395.96 km

The rule of thumb for changing tires is knowing the diameter differences. This difference should not cross more than 3% from your primary tires. 

Here, you can see a difference of 3.9% in the diameter. The circumference difference of 245/75R16 is similar to the diameter difference. Their sidewall difference is also huge.

With a difference of 8.2% in the width and the sidewall height, the 245/75R16 tire is much smaller than the 265/75R16 tires. 

The RPM of 245/75R16 is greater than the other one, as it should be. As it is shown, the difference between the two tires is about 3.7%.

How to read the tire sizes 245/75r16 and 265/75r16?

There are four parts to the tire size 245/75r16, and each part bears a certain meaning. Before you decide to interchange or replace the Tire, you must learn about them. Here is the explanation of each part of the tire size 245/75r16.

  • 245 indicates the width of the tires in millimeters
  • 75 shows the percentage of height in relation to the width or the Aspect Ratio
  • R indicates Radial Construction
  • 16 indicates the Diameter of the Rim

Doing the Same for Tire Sizes 265/75r16

  • 265 shows the width of the tires in millimeters
  • 75 shows the percentage of height in relation to the width or the Aspect Ratio
  • R indicates Radial Construction
  • 16 indicates the Diameter of the Rim

What’s The Difference Between 245/75r16 and 265/75r16 Tire?

By now you’ve learned the basics of using two tires interchangeably. Now let’s see implementing the theory in a real example. Below, we have compared 245/75r16 and 265/75r16 tires in terms of width, aspect ratio, construction materials, and rim diameter. 

Width

If you measure from one sidewall to the other sidewall of a tire, you will get the width. It is expressed in millimeters. You can instantly learn the Width of a tire just by looking at the tire size index.

The first three digits of a tire size index indicate the Width of that tire. As you can see, the first three digits of 245/75r16 are 245. It means the width of that tire is 245 millimeters. 

Likewise, the three-digit number of 265/75r16 tire is 265. It means the Width of that tire is 265 millimeters. So the difference in the Width is 265 – 245 = 20 millimeters.

Now, if you switch to the tire size which is 0 millimeters more or less in Width, it shouldn’t be a problem. 

But you cannot switch tire size depending on Width only. You must consider the Sidewall Height as well. The Sidewall Height depends on Width and Aspect Ratio.

Aspect Ratio

As you can see, there is no difference between the Aspect Ratio of the two tire sizes. Both tires have an Aspect Ratio of 75%. 

But it doesn’t mean that the sidewall height of the two tires will be similar. Due to the difference in Width, the sidewall heights will be dissimilar.

Let’s start with the simple question first: what is the aspect ratio? And its relation with other measurements.

Aspect Ratio is the ratio of the sidewall from wheel to tread and the width. This measurement is usually represented in a percentage.

In our example, 245/75r16 Tire size has a width of 245 with an aspect ratio of 75%. So the sidewall height will be 245 x 0.75 or 7.2 inches or 183.75 mm. You can get the number by simply putting the value on the equation.

Equation: Height of a Sidewall = Aspect Ratio of Tire x Width.

On the other hand, the Sidewall Height of 265/75r16 is 7.8 inches. Though the aspect ratio of the two tire sizes is identical, there’s a gap between the sidewall heights. And it’s because of the different widths of the tires.

This change affects the value of diameter, circumference, and the total number of revolutions per mile.

Construction Type

The tire size index informs you about the Construction Type of a tire. It is expressed by a letter in the tire size index. 

Both 245/75r16 and 265/75r16 have the same letter ‘R’. So, both the tires have Radial Construction in terms of construction type.

Such tires have a sophisticated construction with square footprints on the top. The Radial tires are ideal for driving on-road. 

They are resistant to heat and water. They are next-gen tires and can provide great fuel efficiency.  

Another famous construction type is Bias Ply. They are also known as Cross-ply. It is expressed by the letter ‘B’ in a tire size index. This type is great for driving off-road.

Rim Diameter

To know which tire size fits your vehicle, you must know the wheel rim size of your vehicle as well as the Rim Diameter of a tire. 

For instance, if your vehicle has a 16-inch wheel rim, you can use the tire which has a 16-inch Rim Diameter.

By looking at a tire size index, you can learn instantly the Rim Diameter of a tire. The last two digits of a tire size index indicate the Rim Diameter. It is measured in inches.

As you can see, the Rim Diameter of 245/75r16 is 16 inches. Similarly, the Rim Diameter of 265/75r16 is 16 inches.

It means that if your vehicle has a 16-inch wheel rim, you can use both tire sizes. But make sure to use the same size tires for all the wheels.

Can You Interchange Between 245/75R16 Vs 265/75R16 Tire?

Unfortunately, you can’t use these two tires interchangeably. From the above discussion, now you know that there is a significant difference in diameter and sidewall height between the two tires. 

With a 3.9% change in their diameter, it crosses the boundary of a 3% difference. Thus, it is not recommended to interchange the two tires.

Speedometer Difference: Using the current Tire Size 245/75r16 Instead Of the New Tire Size 265/75r16

Look at the Table. It shows differences in speedometer reading and the actual speed at any given time when the current Tire Size is 245/75r16 instead of 265/75r16. 

Speedo ReadingActual Speed
20 mph (32.19 km/h)20.78 mph (33.43 km/h)
25 mph (40.23 km/h)25.97 mph (41.79 km/h)
30 mph (48.28 km/h)31.16 mph (50.15 km/h)
35 mph (56.33 km/h)36.36 mph (58.51 km/h)
40 mph (64.37 km/h)41.55 mph (66.87 km/h)
45 mph (72.42 km/h)46.74 mph (75.23 km/h)

Speedometer Difference: Using current Tire Size 265/75r16 Instead Of New Tire Size 245/75r16

The table shows the differences in speedometer reading and the actual speed at any given time when the current Tire Size is 265/75r16 instead of 245/75r16.

Speedo ReadingActual Speed
20 mph (32.19 km/h)19.25 mph (30.99 km/h)
25 mph (40.23 km/h)24.07 mph (38.73 km/h)
30 mph (48.28 km/h)28.88 mph (46.48 km/h)
35 mph (56.33 km/h)33.69 mph (54.23 km/h)
40 mph (64.37 km/h)38.51 mph (61.97 km/h)
45 mph (72.42 km/h)43.32 mph (69.72 km/h)

What you must consider Before Interchange or Replace Tire? 

There are important things to consider Before replacing or swiping the Tires. You cannot simply replace the 245/75r16 tire with the 265/75r16 tire that is in a different shape.

For example, if the aspect ratio of the existing tire is 40%, replacing it with a tire that has an aspect ratio of  45% might not be a good option. Doing so will have various consequences on the car’s overall performance, such as variations in top speed and speedometer.

However, to a certain extent, such as minor changes in the diameter or the sidewall, you can switch Tires. However, this can only be done in compliance with the manufacturers’ recommendations.

Anyway, when replacing the Tire, the simple guideline to follow is that the current tire’s size, load index, and speed rating should all match with the replacement Tire.

Load Index and Speed Index of a Tire 245/75r16 and 265/75r16

The load index refers to the maximum load-bearing capacity, whereas the speed index refers to the Tire’s maximum allowable speed at a full load. These are very crucial stats to know before you decide to interchange tires.

Index information can be found on the sidewall right after the Tire size number. It is a combination of numbers and letters that bear a particular meaning. 

Here is an example of how the index information is usually written on the sidewall: 245/75r16 90A. The 90A stands for load and speed index, with 90 indicating a maximum load-bearing capacity of 600 kg, whereas ‘A’ denotes an allowed speed of up to 170 km/h.

Check the load and speed index. They must be as close as possible to fit precisely. These values change depending on the vehicle’s weight and wheel size. Here is a table that shows various load and speed indexes, so you get the idea.

Load IndexKgSpeed IndexSpeed Limit
65290QUp to 160 Km/h
66300RUp to 170 Km/h
67307SUp to 180 Km/h
68315TUp to 190 Km/h
69325HUp to 210 Km/h

Size of the Tire 

The size of the Tire is another vital piece of information to know to exchange the tires properly. The large number on the sidewall shows the tire size.

For example, the marking 245/75r16 on the sidewall represents the size of the Tire. You can also find it in the user manual, on the sidewall, and in other places such as inside the fuel flap or glove compartment.

What Size Tires Is 245/75r16 in Inches?

245/75r16 tires have a 30.5″ diameter, 9.6″ section width, and 16″ wheel diameter.

The circumference is 95.7″ and they make 662 revolutions per mile. The Sidewall Height of this Tire is 7.2 inches.

What Size Tires Is 265/75r16 in Inches?

265/75r16 tires have a diameter of 31.6″, a section width of 10.4″, and a wheel diameter of 19″. 

The circumference is 99.4″ and they have 638 revolutions per mile. The Sidewall Height of this Tire is 7.8 inches.

Conclusion

Interchanging between the two incompatible tires will cause problems like miscalculation in the speedometer, damage to the anti-lock brake system, and suspension & gearing settings. 

This happens because your car computer relies on the input of your factory tire. Changing your factory tire will confuse your car computer. 

So, it would be best if you were unwilling to change your factory tire with an incompatible one. Make sure to know all the statistics about 245/75R16 vs 265/75R16 before changing your tire.

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