[sbasak]

The Alto in India is sold with 145/80R12 tyre. But in UK it is sold with 155/65R13.

Why is this difference? The diameter for both come to nearly same.

155/65R13 => (13*25.4)+(2*155*65/100) = 533 mm
145/80R12 => (12*25.4)+(2*145*80/100) = 537 mm

Is there one size is more advantageous than the other?

[lamborghini]

I guess that since the condition of our potholes is so bad, they decided to give higher profile tyres to improve ride (well that is my reason) or to save costs (Which i guess is Maruti's reason). A 12" tyre will cost less to buy then a 13" one.

[angelfire]

think the alto cost more out thre....so the added benefit 13 inch wheel...the wide tires just improves feel of the car...also better road grip

[drifter]

UK drivers are far more demanding when it comes to handling of their cars...13inch wheels will provide better handling and grip (wider tyres) as compared to 12inch wheels.

But in India, road conditions are pathetic, for the average driver handling and grip do not top his priorities. So 12inch wheels make much more sense as they provide good ride comfort over broken surfaces. And 12inch wheels are less susceptible to damage than 13inchers from our pot-holed roads.

Drifter

[sbasak]

Originally Posted by drifter

And 12inch wheels are less susceptible to damage than 13inchers from our pot-holed roads.

What is the reason for a smaller dia wheel less susceptible to damage than larger dia wheel?

Isn't it that larger wheels are better for bad roads? (eg. trucks rarely suffer in potholed roads)

Cost may be a reason - smaller = cheaper

[drifter]

Truck wheels as a whole are large...but we are talking only about rim size.

145/80R12 vs 155/65R13

A 13inch rim on an alto will have less tyre sidewall protecting it. On the other hand a 12inch rim will have better protection as there is more amount of sidewall surrounding it.

For a 145/80R12 tyre
116mm is the profile of the tyre ie. the height of the tyre measured from the rim.

For a 155/65R13 tyre
100.75mm is the profile.

The 12inch tyre has more sidewall hence more protection.

Drifter

[nitrous]

One more thing,

a 'downsized' tyre will give better mileage. And since Indian customers are driven by mileage figures, this is also a factor.

[jkdas]

I have never seen an Alto in UK, but have seen M800

[speedsatya]

Originally Posted by nitrous

One more thing,

a 'downsized' tyre will give better mileage. .

can you please explain that ?????

as far as i know maruti shifted from 13 inch to 12 inch on the small cars due to bent rims on the 13 inchers...strangely teh wagon r has 13 inch now after having 13 inch ...then 12 inch and now again 13inch..

[SLK]

WagonR 12"??? when? That car would feel unstable on anything soft. That’s why it has a very firm/stiff suspension and 13" wheels with 33psi.

Small wheels and higher profile would provide better ride thats the bottom line, and it does make a noticeable difference. So if there is no demand for performance from the Indian customer its always better to put higher profile tyres.

[nitrous]

can you please explain that ?????

Obviously, the grip levels are gonna decrease, thus a slight increase in fuel efficiency.