I see a lot people like to plus one (+ 1") for their OE tires and ask what sizes are ok, so I thought I write something about it.

1. Motivation
Most of the time, people like to inch up because of the coolness. Having a bigger rim would make the car looks somehow muscular or more aggressive looking. If you look at the higher specification of a similar car, you will also see it is also offered in different rim sizes. Why is it so?

OE manufacturers does a lot of tire size testing before moving on to the tire specification development. Comfort, traction and handling are the main factors an OE manufacturer has to account for. Making a higher inch size available in the market allow the OE manufacturer a bigger leeway to charge a higher price and also to make it justifiable with other addon features.

Grip
The wider you go the higher your contact area resulting in a better traction or braking performance. You do however have to consider whether there is enough room for your extra wide tire.

Comfort
Imagine the sidewall as a flexible cushion which absorbs your weight. This is exactly what the sidewall in the tires does. More often as you go higher in rim sizes, you have to reduce your sidewall height to keep the same outer diameter. This has a pronounce negative effect on car’s comfort.

Looks
A higher inch tire definitely looks much bigger and aggressive looking. Sometimes it also enhances the value of the car as it is being perceive at a much higher status.

Price
Higher inch tires usually also means higher cost. Some owners tend to think the other way by inching down to save money on tires. This is however very rare and most of them like going up.

Check out my post below for more info. I also included a table for a possible relative sizes.

link -->The ulitmate guide to inch up your tire

FYI, putting in bigger tires does got cons, if want to be professional reporting should also list the disadvantage.

- Poor fuel economy
- Odometer may not be accurate
- Electronic stability system may not work as efficient as the safety module is tuned based on the original size. (Certain cars might need to reprogram)
- Suspension system & brakes may put on more strain causing faster wear

This post has been edited by littlefire: Feb 18 2021, 12:13 PM

To be fair to TS, the OP has achieved its purpose of saying what TS is intended to bring up to the forum thread readers here .....
whether in his 'professional' capacity or otherwise , which is immaterial imo .

TS has not expressedly stated there is NO disadvantages in upsizing whilst further add-on or enhancement should be applauded as well .

I suppose an OP is not meant to be end of the thread , but for continuing .............

This post has been edited by zeng: Feb 18 2021, 01:32 PM