DiauR1

iTrader: (3)

My current setup is stock suspension with 245/30/20 front and 285/25/20 rear. I'm suffering when it comes to driving certain parts of the interstate here in southern VA. Could I use a little more sidewall on the tires w/o rubbing issues? TIA guys

my wheels would thank me dearly if it works!

LEXUSF

iTrader: (3)

is it not true that ride is like 80 percent suspension? maybe get coilovers?

mikes rx

iTrader: (14)

No, the problem is that here in our part of VA sections of the interstates are pretty crappy. I just changed from 18" 40-series tires to 19" 35-series tires and I can DEFINITELY feel a difference......since there isn't as much sidewall to absorb the impact

DiauR1

iTrader: (3)

Pothole potholes especially on I64 heading VA beach. Need more tires

mikes rx

iTrader: (14)

Dude that's exactly the part I'm talking about too.....between the HRBT and the 64/264 interchange........just gotta hope the HOV lanes are in your favor in order to avoid all the potholes.

DiauR1

iTrader: (3)

The very thought of it makes me cringe on the way down. That's why we always take the Z with the stock wheels.

I'm pretty sure that tire spec would fit on stock suspension hoping someone could chime in

ek9vboi

iTrader: (3)

Its more of a tire clearance issue. The sizes that you mentioned are over sized in diameter meaning that they will sit taller, thus rubbing might occur. If you don't mind it heating up the panels and stuff to push around to prevent rubbing then go for it. Also, your speedometer will be reading a little bit slower as well, about 3-4mph.

But other then that, you should be ok.

timeToy

iTrader: (11)

Check this site

Front:
Stock: 225/40R19
Overall Diameter: 26.08 in
Sidewall Height: 3.54 in

Tire 1: 245/30R20
Overall Diameter: 25.78 in
Sidewall Height: 2.89 in

Tire 2: 245/35R20
Overall Diameter: 26.75 in
Sidewall Height: 3.37 in


Rear:
Stock: 255/35R19
Overall Diameter: 26.02 in
Sidewall Height: 3.51 in

Tire 1: 285/25R20
Overall Diameter: 25.61 in
Sidewall Height: 2.80 in

Tire 2: 285/30R20
Overall Diameter: 26.73 in
Sidewall Height: 3.36 in

Definitely more sidewall, but also bigger wheels and speedo reading a little slower.

DiauR1

iTrader: (3)

Thanks for the info bro, I wonder what would be the impact if I changed the rears only. Maybe awkard looking stance Increased overall diameter in the rears shouldnt be an issue in terms of rubbing vs the front?

timeToy

iTrader: (11)

If there is too much difference in diameter between the front and rear then you risk confusing the traction control...

DiauR1

iTrader: (3)

Thanks timetoy

lobuxracer

iTrader: (2)

No, it's just the opposite. Tires have more impact than anything. Short sidewalls transfer high frequencies easily where taller sidewalls do not.

Timetoy's list is interesting. I would not change rolling diameters this much for anything because the larger diameter affects scrub radius, roll center, ride height, center of gravity, and just about everything related to real world chassis performance.

If your primary concern is cosmetics (and I'm assuming it is since you've swapped out the OEM sizes for 20" sizes) then you can probably change the tires and not notice any impact. Just don't be surprised if someone in stock IS-F effortlessly drives around you in a turn.

Juanca

iTrader: (5)

I think your front tires are close to stock diameter, but the rears are not. I've seen many people using 245/30-20 front and 285/25-20 rear, that's what I use right now, and the ride is smooth. My suspension is stock and I haven't shaved or rolled my fenders, no rubbing at all except if my car has 4 adults and I go through bumps.

1supra

thats funny I live in the same area with the same size wheels and was thinking about going up to the same sizes you were,how did this turn out for you? know this is old thread but thought some more info might be avail on it now

Pqbrown

iTrader: (9)

I have 235/35/20 on the front on my car with fairly aggressive wheels (8.5 +25) and coilovers that aren't all that low and it rubs like crazy. I would go with a thinner sidewall, it is extremely annoying.