ARTICLE: Choosing The Right Set Of Tyres for your Car

[gowda79]

Please let me know which is the widest tyre can be put on Safari without making any alteration to the body of the vehicle

[iraghava]

I would say 255/65 R16 would be a nice size on the Safari without needing any modifications to the arches.

[nripin]

Originally Posted by kpzen

you will need 12" 114.3 PCD alloys and 145/80-12 tyres.

Thanks KPZEN i got the 145/80-12 size ones

[nripin]

Originally Posted by binz

Isnt the oe 13"?Or did you mean M800 rims?

Yes my OE size is 13"its a 99 model Carb Zen.

But the Rims i got was 12 "

[Xehaust]

Now we all have gained a lot of knowledge as to choosing the right set of tyres from the thread HERE (READ FIRST: Choosing The Right Set Of Tyres for your Car) by Rehaan.
While that thread discusses on how to choose the right set of tyres & all the technical knowledge regarding PCD's and what are all those markings and numbers all about. Eg. What does 205/55 R15 mean.
And also things like tubeless, tread patterns and so on.

My aim here is to spread & discuss knowledge on the implications, the pros & cons and the do's & dont's of tyre UPSIZING/UPGRADING.
In short, what happens after you choose your tyres and what are the consequences.

To start off id like to point out a simple misconception. Ya ya, i know that most of you know this but id like to share this with people who don't.
So here goes:




What is the difference between UPSIZING & UPGRADING?
To put it in a nutshell -

"UPSIZING" is when you increase the size of your rims.
Eg. You "UPSIZE" your Swift rims from 14 inches to 15 inches.
UPSIZE leads to a change in your rims & tyre size.


"UPGRADE" is when the rim size remains constant but either your tyre size changes or you buy better rubber of the same tyre size as well.
Egs. You "UPGRADE" your Swift 165/80 R14 tyre to 185/70 R14 tyre. You see, here the RIM size (R14) remains the same.
OR
You "UPGRADE" your SWIFT 165/80 R14 MRF tyres to 165/80 R14 Yokohama tyres. You see here that even the size remains same but the brand of rubber changes. This is also called an UPGRADE as the compound used by Yokohama to make their tyres is more suited to handling performance than the compound used by MRF.
So they are superior in quality you might say. This is also wrong as quality depends on the aim of use of the tyre. MRF makes them for comfort, Yokohama makes them for handling performance. Thereby, both may be of equal quality but enthusiasts call it an UPGRADE. Day to day car owners may call MRF an UPGRADE over Yokohama if the comfort is higher and tyre noise is lower even though handling is poorer. So you see, it's all relative.
So, we summarise "UPGRADE" by saying that RIM size remains constant, the tyre size may or may not change but it is still an upgrade.









The implications,pros & cons and do's & dont's of UPSIZING/UPGRADING.
I will discuss in points to make it easier to read & remember:

1> Handling is not only dependent on the tyres but also on the chassis of the car. So by only upgrading or upsizing doesnt mean that you will get huge amounts of handling performance. (Though they do help )


2> Upsizing leads to loss in ride quality even though it leads to gain in handling. So the bigger the upsize, the more your behinds will feel our roads.


3> Most cars are happy with a +1 upsize, meaning that you can go 1 inch bigger. Eg. Alto has 12 inch rims, so 13 inch should be ok. +1 upsize is a balance between loss in ride comfort and proportionate gain in handling performance. The higher you go after +1, the higher the loss in ride comfort as proportionate to the VERY marginal gains in handling.

YES People, this and the next point is specially for those of you who want to go in for those huge bling bling rims. Remember, huge rims and almost negligent rubber are a fad in other countries simply because their roads are super-smooth thereby giving VERY VERY pleasing aesthetics to the car and good handling.
Our roads eat up suspensions for snacks, so you know how your butt will feel not to mention that ever widening hole in your pocket. Read on to know why.

4> HIDDEN COSTS!!! Another thing to note is that the bigger the UPSIZE, the more overtime your suspension and other parts of the car will put in to cope with it.

This will not only lead to higher wear and tear of mechanical parts but also bigger maintainance and repair bills.

Finally, in case of an UPSIZE or UPGRADE, the thicker the tyres, the lower the fuel efficiency. Due to higher rolling resistance and added weight.






FINALLY, id like to end on a startling discovery (About UPSIZING) that came to light in my tiny little head after reading an article. Here is poor ol' me sitting and typing the article about the startling discovery:

The basic 'funda' of upsizing is to keep the overall diameter of the tyre constant (ideally) or within 3% (Plus or Minus) of the original diameter.

<<People, this is why we consult each other before upsize>>
<<Now, the reason behind it>>

If this rule is not followed, your car's speedometer will give you incorrect speed readings and your odometer will give wrong distance covered readings. In extreme cases, it may also conflict with the ABS system in your car.



HOPE THIS THREAD HELPS A LOT OF PEOPLE IN UNDERSTANDING WHAT UPSIZING/UPGRADING IS ALL ABOUT.

P.S. - This took me 2hrs to type & not to mention the thinking involved on how to structure this post. We BHPians should get paid for such consultation

[Ricky_63]

Hey thanks for all the enlightening !! So I should say I am upgrading my A4 tyres as I intend to keep the OE rims, but move from 205/55/16 to 225/50/16

Cheers

[ram_hyundai]

xehaust,i can understand the time you spend for such a long post.good job done.but it would have been better if you could have split this post into two parts and then you have more time and you could have covered more points.what i thought and immediately went through my mind was almost all the points are covered in the tyre upsize discussion forum in different posts.
the better part of your post is that almost all the points are covered in a single post.
ram

[HappyWheels]

good one xehaust; appreciate the effort and the quality of the post! :-)

[PatienceWins]

Good One!! You have covered all the pros and cons very well.

[itzzme]

Pardon my ignorance but i learnt :
Upsizing is broader tyre on the same rim size.
Inch-up is increasing the rim size.

[PatienceWins]

Originally Posted by itzzme

Pardon my ignorance but i learnt :
Upsizing is broader tyre on the same rim size.
Inch-up is increasing the rim size.

No

Upsizing is increasing the size of the rim. For eg. Upsizing from 14" rim to 15" rim.

Upgrading is increasing the width of tyre with NO CHANGE TO RIM SIZE. For eg. upgrading from 175 65/R14 to 195 60/R14.

[sj_koova]

Thanks Xehaust,

Good. Now I know the right meaning for some jargons.

[amit_mechengg]

there is a new model launched by plati in 12" costing 10000 for a set of 4 wheels.
i am planning to put it on alto. but the dealer is asking me to stick to the stock size 145/80 r12 michelin as i dont have a power steering.
please guide me gurus. shall i got for 13" or 12" ...and please give me the correct tyre size. shall i retain the same or upgrade to 155/80 ?? can these fit on 12".
he is also saying that the alloys are half inch wider than rims so the 145/80/ r12 will expand more on 12" alloys and give me a better road grip.

[tsk1979]

Note from mod: Threads merged, please do not start new threads for similar topics, use existing threads wherever possible

[vasudeva]

Help me Please

I have a Opel Corsa 1.4 GSI with 37,000 kms and old tyres (175/70R-13, Bridgestone). The car is being driven by my beloved and based on her usage, annual km driven is around 2000 kms. I plan to keep the car for another 2-3 years. In that time, it will reach around 43000-45000 kms.

Right now, the tyres are OK and should remain so even when I sell it. The question is that since my wife will use it for 3 years, I plan to spend some money on changing tyres, primarily for ride and comfort. As of now, the tyres may have close to 10000 km life, but for me that does not matter.

I would appreciate your advice if changing tyres at 37K will appreciably improve ride and comfort. Even a better but not appreciable improvement in ride and comfort would be sufficient reason to change tyres before their life. If that is yes, should I buy Michelin XM1 175/70-13. What about Bridgestone. Would these cost me around Rs. 3K/tyre. No plans for upsize. Ride and comfort is very important, so perhaps even an upsize may be ruled out, unless someone knows better. I would really appreciate an advice with ride and comfort being the top priority, rather than performance ( my wife does not exceed 60!).