My car: Suzuki Celerio (EU/India) / Alto (Asia) 2010 mdl.

Hi, I'm downsizing from a r14 rim size to a r13. Current tire size is 155/65/r14 and that is the OEM size. My current rim spec is 14x5.5 et38 Rota alloys (wider than oem spec which is 14x4.5 et45 steel rims).

I have two option for tire sizes: 1.) 155/80/13 (taller sidewall) OR 2.) 165/70/13 (wider but same as OEM diameter, more accurate speedometer).

I found cheap alloy 13x4.5 et45 rims (from a Daihatsu Charade) that match up to my car's oem specs

The reason for the downsizing is because I am not satisfied with the current tire's ability to absorb potholes, I recently changed front struts (from old busted ones) and it seems that the tires are really just not pleasant to use on bad roads like the ones in my country.

Do take note that in India (where the Celerio is made) the oem tire size there is 155/80/13. The roads there are pretty bad too, potholes galore.

What is the optimal tire size? Should I go for a taller tire or maintain the OEM diameter? Would the slightly wider tire negate any efficiency benefits I get from downsizing?

  • Larger wheels will tend to "roll over"pot holes; smaller wheels will fall into them making impact worse. Mar 16, 2020 at 15:08

1 Answer 1


I have driven in India and i have the x-rays of two broken ribs to prove it.

I use the Tire calculator from tacomaworld.com to compare tires sizes, it is very handy.

You just enter size you have and the size you are thinking about buying and it will show your specs and an image of relative size differences.

You play with it until you get tires of equal size or of the maximum size your vehicle with take. ( that is an important thing to know so you do not buy a tire to big for your vehicle )

To figure out your vehicles stock tire size you can use Wheel-size.com

Tire size is Three part code: example p215/65 R15. the first number 215 is the width in Milometers of the tire and the second number is an aspect ratio ( or percentage ) of the width. The third number is the size of the wheel or rim 15 inch wheel. So in your case if you want a sidewall that is taller then you would choose tire with a higher second number I.E. A tire with a second number of 65 will have shorter sidewall then tire with 85 as a second number.

For potholes you would want a tall sidewall to absorb the impacts.

  • I am aware of tire size calculator that is why I already present 2 choices in my original post. My main concern is whether I should sacrifice speedometer accuracy for more comfort (taller sidewall) or should I maintain OEM circumference (with a bit wider tire) for accuracy and stay within specs.
    – leoblack9
    Mar 16, 2020 at 5:09
  • @leoblack9 on the tacomaworld calculator is a chart that tells you of the difference in speedometer readings. If you know that number you can then make adjustments to your driving. It tells you the speed Example: speedometer reading;50 mph (80.47 km/h) Actual speed; 48.23 mph (77.62 km/h)
    – Alaska Man
    Mar 16, 2020 at 17:07

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