zBear

iTrader: (12)

I am debating whether to stay 18s or go 19s and have a question.

I know 18s are going to be faster than 19s in straight line acceleration because they are lighter, but how would the same setup handle in turns and slaloms? Would 19s hold the road less efficiently than 18s? I don't think they would, but lets see what the tire gods say.

Z04

iTrader: (15)

the front is a 0.04% diameter difference and the rear is 0.63% diameter difference. so basically, it will be nothing you will notice at all since those tires are pretty close

terrasmak

iTrader: (8)

Should be the same depending on surface. The surface could change either one better or worst.

Spike100

As terrasmak says, you won't notice a difference in handling. The 18" setup will provide a slightly more comfortable ride (cushioned by the slightly higher sidewall... but those widths hold a lot of air, so even the comfort-factor approaches negligible). The 19" wheels will look better.

I'm not sure about acceleration and the the weight difference. I'm guessing acceleration will be less with the 19's".

--Spike

Z1 Performance

iTrader: (564)

there is really no way to answer this question

the handling difference will come as a result of the specific tire you are talking about, the alignment specs of the car, the width and offset of the wheel they are being installed on. The size stamped on the side is the least important aspect of whether it will handle better or not

zBear

iTrader: (12)

Assuming everything is the same other than wheel size and tires size, for example:

18in TE37 9.5/10.5 +22 all around
255/40/18 295/40/18
Michelin PS2
Alignment F -1.3 Camber/R -1.5 Camber/0 Toe

19in TE37 9.5/10.5 +22 all around
255/35/19 295/35/19
Michelin PS2
Alignment F -1.3 Camber/R -1.5 Camber/0 Toe

Am I going to lose that much handling running 19s over 18s? 18s are no doubt the better setup if you want all out performance. But 19s just look better on the street.

Z1 Performance

iTrader: (564)

first, not sure who suggested those sizes, but they are way out of whack. On your 18 inch example, it's way too much stagger, and you'll upset traction control and vdc. It's also going to look quite goofy with it's huge sidewall. I recomend you keep front to rear stagger to under 3% total difference, just as the factory does.

same goes for your second tire choice sizes...they are too off base, over 4% difference, which is no good

255/35 front and 285/35 rear would be ideal in an 18

265/30 or 275/30 front, 295/30 rear would both work well in a 19. Or, 265/35 front, 285/35 rear in a 19 also would work

I run 265/30 front, 285/30 rear on my own car, for a bit over a year now, and it works great

Z1 Performance

iTrader: (564)

best bet is to play around with a tire calculator ^

zBear

iTrader: (12)

I'm currently running 265/35-18, 285/35-18, but wanted to up the rear to 295 for more traction and lower the front a little for less heavy steering. I wanted to go as wide as possible in the rear without having to do any crazy camber and 295 looks like the ideal choice.

I came up with the numbers myself using the Tire Size calculator here and they came out like this.

Stock
F 225/45-18
R 245/45-18

Original Tire Choices: % Compared to Stock
F 255/40-18 +0.2%
R 295/40-18 +2.3%

F 255/35-19 +0.2%
R 295/35-19 +1.7%

Your Suggested Choices: % Compared to Stock
F 255/35-18 -3.6%
R 285/35-18 -3.1%

F 265/30-19 -2.7%
F 275/30-19 -1.8%
R 295/30-19 -2.7%

F 265/35-19 +1.3%
R 285/35-19 +0.6%

I was trying to keep tire sizing as close as possible to stock, so I was going with 40 profile for 18s and 35 profile for 19s.

If I'm reading correctly between the lines, then I should be OK running 265/35-19, 295/35-19 or if I stick with 18s then 265/40-18, 295/40-18, just keep my stagger closer to stock.

You're running 265/30, 285/30. Are you running 30 profile because it's help tire flex?

Z1 Performance

iTrader: (564)

You are wanting to keep the overall rolling diameter of front to back to under 3%

265/35/19 and 295/35/19 is a difference of 3.03%....which is just out of what you want

My setup, for example, is a 1.87% stagger.