potmilkz

My brother is putting on some 19's on his car..

wondering if there is any problem running 30 series front and 35 series rear? he wants a little more meat in the back..

this will be on a 2012 accord coupe.

justnspace

iTrader: (1)

when some one wants more meat in the back, they generally go for a wider look.
your brother, however, is changing the profile height and not the width.

it will look AWKWARD, a lower profile in the front and a thicker sidewall in the back.
I'm not to sure why he's doing this.....

Unless he is stretching tires.
usually, a stretch is still lowering the profile and width....

Please post tire specs.

potmilkz

lol.. i dunno.. i asked him why.. he just said he wants to.. he just wanted me to ask.

but the question remains.. will this cause any problems

hes running 245/30/19 and 255/35/19..

justnspace

iTrader: (1)

pshh.. man, you guise need to learn about tires..




When you are considering changing the wheel and tire size on your vehicle, the important thing to remember is that the overall diameter of the tire/wheel combination should be close to the original sizing.

To find out the overall diameter of your original tire/wheel combination the first thing you must be able to do is read the tire:

Example:

225/40R18

225 – Section Width in mm (Section Width or Tire Width is the measurement of the tire from sidewall to sidewall)

40 – Section Height/Aspect Ratio (Aspect Ratio is the ratio of the height of the tire’s cross-section to its width. In this example, 40 means that the height is equal to 40% of the tire’s width. This is also sometimes referred to as “Series”.)(profile)

R – Construction (The "R" stands for radial, which means that the body ply cords, which are layers of fabric that make up the body of the tire, run radially across the tire from bead to bead. A "B" indicates the tire is of bias construction, meaning that the body ply cords run diagonally across the tire from bead to bead, with the ply layers alternating in direction to reinforce one another. Newer tires also have new sport constructions, such as Z. See your preferred tire manufacturer’s website for details.)

18 – Wheel Diameter (18” diameter)

Sometimes your tire will have a letter in front of this information indicating “P” for passenger car or “LT” for light truck.

Formula for Calculating Tire Dimensions

Using the above example once again - 225/40R18

1. 225 mm divided by 25.4 = 8.86” (section width)
2. Multiply 8.86 (section width) by .40 (aspect ratio) = 3.54” (section height)
3. Multiply 3.54 (section height) x 2 then add the rim diameter (18) = 25.08” which rounds up to 25.1”.

25.1” would be the tire dimension for this particular example.

Tire Size Calculator
http://www.motegiracing.com/techzone...me=totaltech1#

justnspace

iTrader: (1)

TL;DR - use the calculator to find the closest rolling diameter for both front and rear.

its not that freaking hard to understand.

justnspace

iTrader: (1)

so in other words, the width and profile height go hand in hand.
your Original post is incomplete and missing info.

your brother wants a wider tire while keeping the same rolling diameter.
use the calculator to find out what tire comes closest to stock.


ALSO, WHY THE FAWK DOES HE WANT WIDER IN THE REAR!?!
FWD vehicle...

Mr Marco

This will just add more unsprung weight and drag on the front end. Unless he's getting them for free, he should stick with 245/40/19.

potmilkz

thanks guys. ill let him know..

as far as reasons.. i cannot tell you.. he just wants what he wants..

Edward'TLS

Wider tires on the rear of a FWD car will further increase the understeer tendency of the already defaulted understeering front-heavy FWD car.

Not a good move, unless the car owner want his/her car to handle like crap.

justnspace

iTrader: (1)

^he can put the same width all around.
it would look better and handle better than having his purposed setup.

again, your brother is weird.
ask him WHY he wants to do this.

Tomathon

Yes this will create an issue with the ABS system, which relies on wheel speed sensors. Overall rolling diameter of front is significantly smaller than the rear.

BTW.. total diameter of wheel including tire is smaller on the front than the rear as well, so his car will look funny.

And as Edward TLS said he would be negatively impacting his handling especially since his car is FWD. If it was SH-AWD this would matter less as the torque vectoring quality would be able to utilize the increased rear tire width to push the car around the corner.