235 40r18 vs 225 40r18 Tire – The Main Comparison

Are you considering investing in new tires for your vehicle but caught in a dilemma when choosing between 235 40r18 vs 225 40r18 tires? Don’t panic; it is a common problem for many vehicle owners who are wondering which one is better between these two tires. 

We researched a lot about these two tires and found several differences and also some similarities between them. Now we are sharing our research results with our readers in this article to help you choose the right tire size after reading through.

The following parts will give you a numeric comparison guide between these two tires to provide the best-fit tire size for your vehicle. As a result, your driving will be a breeze with maximum stability against all terrain surfaces.

Comparison table between 235/40r18 vs 225/40r18 tires

235 40r18 vs 225 40r18

235 40r18 and 225 40r18 tires are excellent for providing maximum stability and greater traction on all-weather surfaces. If you examine them closely, you can easily determine their apparent differences. Let’s look at the comparison table for a quick idea of the difference between 235 40r18 vs 225 40r18 tires. 

Characteristics 235/40r18225/40r18
Width Diameter 9.25 Inches8.86 Inches
Overall diameter 25.4 Inches25.9 Inches
Sidewall height 3.70 Inches3.54 Inches
Rotation 79.8 Inches78.81 Inches
Rollings per mile in kilometers793.97 Inches803.94 Inches
Rim diameter 18 Inches18 Inches
Rim width 8.00”-9.50” (inches)7.50”-9.00” (inches)
Radius 12.70 Inches12.54 Inches
Speedometer reading 101.2 (kph)100 (kph)

235 40 R18 vs 225 40 R18 Tires: Discussion on Differences 

It is time to check the top main difference features as mentioned in the above table. Our detailed discussion will help you get a clear understanding of their differences. In addition, read through the whole article to grasp all knowledge about these characteristics. 

Width Diameter

  • Width diameter indicates your tire’s contact patch with the road surface.
  • It offers an increased grip for maximum control.
  • It increases maneuverability and easy handling.

If we compare the Width diameter of these two tires, we can quickly determine their differences. A 235/40 R18 tire comes with a width diameter (inches/mm) of 9.25″/235. 

On the contrary, a 225/40 R18 tire comes with a width diameter of 8.86″/225. You can determine there is a difference of 0.39″/10 (4.3%) from the previous tire. As a result, it is an ideal alternative for narrow tire lovers. 

Overall Diameter

  • The overall diameter enhances stability on the road.
  • Improves your vehicle/car’s cornering ability.
  • A larger overall diameter makes the sidewalls stiffer and shorter as well.

You can also find a dissimilarity between these two tires based on their overall diameter. For example, a 235/40 r18 tire features a 25.4″/645.2mm overall diameter. 

In contrast, a 225/40r18 tire features a 25.9″/637.2mm overall diameter. In addition, it is 0.31″/8mm (1.2%), different from the 235/40 r18 tire.

Sidewall height

  • Larger side walls provide extra cushioning for your tires.
  • Provide improved contact and ground clearance for stability.
  • Sidewall height ensures more hold or easy handling performance.

There is a considerable difference in the sidewall height of 235 and 225 tires. As we know, a 235/40 r18 tire comes with a 3.70″/94mm sidewall height. It makes this tire’s sidewalls strong enough to carry extra loads. 

On the other hand, a 225/40r18 tire comes with a 3.54″/90mm sidewall height to provide optimal performance. There is a clear difference of 0.16″/4mm (4.3%) between these two tires’ sidewall heights.

Rollings per mile in kilometers

  • Rollings per mile in kilometers indicate the rollings number a tire covers per mile.
  • It lets you determine the rotation ratio of your tires.
  • It is measured by previous testing experience or in the laboratory.

Another difference between 235/40r18 vs 225/40r18 tires is their rolling ratios per mile. The first one features 793.97″/493.35mm rollings per mile in kilometers. 

In comparison, 225/40r18 offers 803.94″/499.54mm rollings per mile in kilometers. The difference between the rollings ratios of these two tires is 9.97″/6.19mm (1.3%). So, determine the tire size by considering its rolling ratios for a smooth ride. 


  • Rotation of tire means a periodic change of your vehicle’s tire.
  • It lets you prepare for the next tire-changing time.
  • It indicates how much your tire will run in a certain period.

235/40r18 and 225/40r18 tires clearly compare their rotation ratios. The first tire has a rotation ratio of 79.8″/2026.96mm, while the second features 78.81″/2001.82mm. However, the difference between these two tires’ rotation ratios is 0.99″/25.13mm, which is (1.2%).  

Rim width

  • Rim width ensures that your tire is compatible with your wheel.
  • It offers better cornering performance for your car or vehicle.
  • It helps to get a perfect fit tire size for your vehicle.

The rim width of a 235/40r18 tire is 8.00″ -9.50″, which can easily fit your vehicle. On the contrary, a 225/40r18 tire comes with a 7.50″ -9.00″ rim width. There is a clear difference in rim width between these two tires. A 225/40r18 tire’s rim width is 0.50″ -0.50″ smaller than the 235/40r18 tire’s rim width diameter.


  • Radius measured from center to circumference of a wheel.
  • It improves your vehicle’s stability.
  • It impacts the acceleration to compromise overall speed.

The 235/40r18 tire comes with a radius of 12.70″ compared to the 225/40r18 tire with a radius of 12.54″. You can determine the new tire’ distance is 0.16″ smaller from the center to its circumference than the previous tire.

Speedometer reading

  • It shows you the speed of your tire per kilometer.
  • It can slightly vary from the recommended speed.
  • It helps you to determine the difference between actual speed and speedometer reading.

If you check the speedometer reading of the 235/40r18 tires, it will show 101.2 (kilometer per hour). You will see 100 km per hour for 125/40r18 tires in the speedometer reading. The literal difference is 1.2 between 235/40r18 and 225/40r18 tires. 

Similar features between 235 40r18 vs 225 40r18 tires

Apart from the dissimilarities, these two tires also have some similar features. Let’s check the similarities between these two tires from the following table.

Features235 40r18225 40r18
Tire aspect ratio40.0”40.0”
Load index rating92.092.0
Load capacity1389 pounds1389 pounds

This table shows the similarities between 235/40 R18 and 225/40 R18 tire sizes. According to the following features, I have discussed the similarities between these two tires in this table:

Tire aspect ratio

  • The tire aspect ratio offers better steering capacity.
  • A bigger aspect ratio provides greater riding comfort.
  • It helps to reduce rolling resistance to overcome uneven surfaces.

The 235/40r18 and 225/40r18 tires come in the same tire aspect ratio, 40.0″. 


  • Radial construction ensures maximum grip for stability.
  • It offers a lower fuel-burning facility than other construction tires.
  •  Run cooler to offer a smooth ride and longer tread wear.

235/40r18 and 225/40r18 tires feature built-in radial construction for a smooth ride.

Load index rating

  • Load index rating lets you know your tire’s maximum loading capacity.
  • It helps to reduce or stop tire blowouts on the road.
  • It keeps you safe from facing any unwanted accidents or damages.

The load index rating for both tires is 92.0. 

Load capacity

  • Its built-in strong plies keep it in ideal tire shape.
  • Higher load capacity allows you to carry higher/ larger loads.
  • It provides better traction control for a smooth ride.

Both tires come with 1389 pounds maximum loading capacity.

difference in performance between 235 40r18 vs 225 40r18 tire

Excluding the above-described dissimilarities between 235/40r18 and 225/40r18 tires, they have the following differences in their performance. Check the following detailed differences in their overall performance to get the right tire size for your vehicle.

Handling performance

Larger tires are designed to provide greater handling performance for their users than smaller tires. Due to this nature, the 235/40r18 offers superior handling performance than the 225/40r18 tires.

Gripping performances in different weather conditions

Bigger tires come with less disposal ability under the tire surface; that’s why they have the less gripping capacity in water, sand, and dirt surfaces. On the contrary, smaller tires come with greater grip on all weather conditions of their great dispelling capacity under the tire. As a result, 235/40r18 and 225/40r18 tires offer better grips than 235/40r18 tires.

Fuel consumption

Wider and larger tires have more rolling resistance features than smaller and narrower tires. The more rolling resistance a tire is, the more fuel it burns. Bigger tires also reduce speed than smaller tires. Therefore, 225/40r18 tires offer greater fuel economy than 235/40r18 tires.

Also Read: 235 40R18 vs 245 40R18 Tire – Comparison Explained

My Opinion about 235 40r18 vs 225 40r18 Tire Size

When comparing 235 40r18 and 225 40r18 tire sizes, there are a few differences to consider. The first is the width of the tire, with the 235 being wider than the 225. The second difference is the aspect ratio, with the 235 having a larger aspect ratio than the 225.

The wider 235 tire size may offer better handling and stability in certain driving conditions due to the increased contact patch with the road. This wider tire size may also result in a decrease in fuel efficiency and potentially a rougher ride.

On the other hand, the 225 tire size may offer better fuel efficiency and a smoother ride due to the smaller contact patch with the road. However, it may not provide the same level of handling and stability as the wider 235 tire size.

Ultimately, the best tire size for you will depend on your driving needs and preferences. It is important to consult with a tire professional and consider factors such as your vehicle compatibility, driving conditions, and budget when making a decision.

Frequently Asked Questions

People asked several questions about these two tires. Check the following questions and their answers to satisfy your further query.

What is 225/40R18 tire sidewall height?

The 225/40R18 tires generally come in 3.5″/90mm sidewall height. You can determine this measurement of your tire’s sidewall. Measure it by placing a measuring tape from the wheel rim to the top of your tire’s tread. 

What does 235/40 mean on a tire?

235/40R18 tire means its width is 9.3″ or 235 mm. It displays the width of the tire that you can measure from its center to outer sidewalls. In addition, the term “tire width” also refers to the width of the section, tread, or cross-section.

What does 225/40 mean on a tire?

The 225/40R18 tire means a tire’s width is 225mm. You can measure your tire’s width from its center to its widest circumference. It is exactly 225 millimeters from the rim to the tread top if your tire is 225/40r18. 

What is the difference between 225 and 235 Tires?

There are several differences between 225 and 235 tires. The main contrast between these two tires is their width. For example, a 225 tire measures 225mm while a 235 tire measures 235mm. 

Final Thoughts

The difference between 235/40r18 vs 225/40r18 tires is based on their comparative features. You can see both have dissimilarities in their width and overall diameter. Moreover, they are different in their rim width, sidewall height, and more.

A 235 tire is suitable for their usage for heavy vehicles/ larger automobiles. On the other hand, a 225 tire is suitable for lighter vehicles/ regular automobiles. 

I am an engineer and the chief editor of tireslover.com, I am a passionate blogger as well. I am the person who can ensure a perfect, informative, honest, and helpful, guide with 10 years of work experience with different varieties of tires.

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