Every thing you need to know about upsizing

Tyre Upsizing in India is a growing market. Upsizing tyres definitely adds a personality to a car and is seen as a style statement . However most of the drivers going for tyre upsizing give only one brief to the tyre dealer- "I want broader car tyres" and then he leaves it to the dealer to decide which tyres are put on his car. Generally tyres with aggressive design patterns are pushed and gullible drivers have no option but to go with dealer recommendation on the tyre brand which they will have on their wheels.

Indian tyre market is awash with stories how consumers have been cheated on various accounts. Vehicles have been fitted with tyres which touch on side panels when turning , taken off tyres smuggled from Dubai have been installed, completely unknown Chinese and Taiwanese brands have been fitted, instead of doing inch up the tyres have been down sized and many more . It is clear that consumer education is lacking when it comes to tyre upsizing. Situation has been compounded by the fact that consumer does not have time to do research for his tyres while he goes shopping. Moreover not much information is available on upsizing tyres and even if it is available then it is scattered.

Before we studied brands it was important that we pick the tyre size which is best for upsizing for a given car. There are quite a few alternatives when it comes to replacing OE fitted tyres. However not all qualify for upsizing. We fed the tyre sizes into special computer software programme and then came with perfect technically suitable tyre size. Hence our readers can be sure that the best tyre upsize has been selected for their cars.

However there was one issue which still needed to be sorted out i.e. the patterns. In India the tyre upsizing market has been dominated by unidirectional V shapes patterns. These patterns look interesting when consumer steps into the store to buy. With no other information in place this is the only thing which consumer sees and basis his decision on. The thought process being if it looks good, it must be good.

Fly by night operators in the industry source such tyres from China and Taiwan and place it on the shelves. Some of the tyre dealers in Karol Bagh and Lajpat Nagar in Delhi are too happy to sell these tyres. It gives them fantastic margins, does not have prices listed and being nice looking it’s easy to convince a customer. However these tyres have problems which escapes attention of a consumer. These tyres make too much of a noise after couple of months and that is very irksome .World leaders in tyre manufacturing are moving away from these unidirectional tyre patterns . Pirelli no longer sells these tyres and Michelin has no such kind of tyre pattern in their product portfolio. Worldwide companies are shifting to asymmetrical patterns. These tyres are designed to give much better performance and also designed to dissipate noise.

As you would have realised by now that all aspects - technical , commercial , availability , warranty etc have been thoroughly analysed while preparing these recommendations . We sincerely hope that this will help you decide on the best tyre upsize for your cars.

TYRE UPSIZING : THE TECHNICAL ASPECTS

There is a method behind the madness when it comes to upsizing of tyres and wheels. Manufacturers offer a standard size of tyre and wheel rim on a car for a reason. They try to strike balance between  increasing performance dynamics of a car, increase fuel efficiency of the car, offer a more comfortable ride, decreased tread wear, provide good dry and wet braking response and decrease road noise. In short they choose the best compromise. However with upsize you can choose performance in certain aspects over the compromise.

Manufacturers do leave room in the wheel well for a calculated upsizing of tyres and wheels on their cars. This is done so that owners can upsize the tyre and wheel size to increase performance and or increase traction on different road conditions. It is generally accepted that  maximum calculated upgrade that can be done without upsetting the cars driving dynamics is around 3% of the original size of the wheel rim. Any upgrade above this will result in a noticeable drop in fuel efficiency and compromise on ride and handling of the car. Too big an upgrade in wheel and tyre size will also increase the weight of the car giving the driver no real benefit from the upgrade.

It is advisable to go for an upgrade anywhere between the 3% margin for better performance and handling, increased grip and creating a visual appeal. Do take note that upsizing the wheels and tyres will decrease the fuel efficiency of the car and will result in speedometer error on the car.

You will get following benefits if you decide to go for upsizing of your tyres :

• Improved response to direction changes
• Greater contact area with the ground
• Increased traction
• Greater overall control and handling
• A sleeker and more modern appearance

UPSIZING TYRE : THE SIMPLE MATHS BEHIND THE METHOD 

To a car owner, knowing the biggest wheel size that can fit into a vehicle is very important. There is a simple rule, which we also applied- upgraded wheel's diameter should not be larger than 3% of the original. For example, if we take the 185/65R15 specification as an example, with the original diameter size as follows:

Wheel diameter: 15 inches, 15 inch × 2.54 cm = 38.1 cm
Sidewall: 65% of the tyre's surface, ?18.5 cm × 0.65 = 12.025 cm

But as each wheel has two sidewalls, the sidewalls have to be multiplied by 2,
Sidewall: 12.025 cm × 2 = 24.05 cm
Diameter: 38.1 cm + 24.05 cm = 62.15 cm

Is it possible to upgrade to a 205/60R15 tyre?

Wheel diameter: 15 inches, 15 inch × 2.54 cm = 38.1 cm
Sidewall: 60% of the tyre’s surface, 20.5 cm × 0.6 = 12.3 cm

As before, as each wheel has two sidewalls, the sidewalls have to be multiplied by 2
Sidewall: 12.3 cm × 2 = 24.6 cm
Diameter: 38.1 cm + 24.6 cm = 62.7 cm

Compared with the 185/65R15 specification tyre’s diameter of 62.7 cm, the difference is only  0.88%, which is well within the allocated range.

WHAT THE "PLUS 0"  "PLUS 1" AND "PLUS 2" MEAN FOR TYRE UPSIZE ?

In Plus 0 upsizing the Rim diameter remains same , width of the tyre is increased and profile is decreased.Note: Advantage is that you can upsize without changing factory fitted Rims.

In Plus 1 upsizing  the Rim diameter is increased by  1 inches with increase in width and reduced profile.
Note:  It will Require you to change the Rim of your vehicle

In Plus 2 Upsizing  the Rim Diameter is increased by 2 inches
Note: It will Require you to change the Rim of your vehicle