ychachad

One of the best upgrades one can do very cheaply without sacrificing ride quality is changing the stock tyre from 225/60-16 to 235/60-16. The extra rubber provides a good bit of grip around corners, believe me. You also get a small boost in fuel economy.

GRAND_LS 4

iTrader: (2)

How do you get better fuel economy and better grip, they somewhat contradict each other. Not to mention the increased diameter.

RA40

iTrader: (6)

The increased diameter with the lower rev's per mile will give him a very small increase...maybe about 8% or about 1/20th a mile at highway speeds. He does have a slightly larger contact patch yet the sidewall height will also increase. The handling will depend on the manufacturers spec for the tire.

In a hi-po to ultra hi-po A/S, this may be possible say a Michelin Pilot Sport A/S or Pirelli P-Zero Nero but these aren't available in this size. I turn up a Pirelli P6 Four Seasons Hi-Po A/S, likely a bit better than the Michelin MX4V stock rubber. (Which IMO isn't that good to begin with.)

But YMMV as they say.

ychachad

You nailed it.
Another advantage is that it reduces the fender gap, and makes the car look sportier.

RollinOn19

Rolling on 19's

GRAND_LS 4

iTrader: (2)

Maybe its personal preference, but adding a higher sidewall doesn’t make it look sportier to me. Technically speaking, the higher the sidewall, the more the handling diminishes theoretically. The fender gap shouldn’t really change as much, and the amount gained will be paid for by increasing the height of the car (also decreasing your center of gravity, so you have a higher sidewall, and increased overall height). However, 235/55/16 sounds promising, if you can find that size in a tire you like.

All in all, the changes will be very minimal, but it doesn’t hurt to discuss and learn from everyone.

D2-AUTOSPORT

I would suggest 20", and if you want to go larger, then 21" staggered.

With the proper lowering, 20s look great

RA40

iTrader: (6)

Changes within 5% aren't going be dramatic as per my discussion with the Michelin rep. Lexkost posted in another thread a tire size calculator and the effects of varying sizes on mileage and speedo readings.

The 245/40-18 is 25.7" and the stock is 26.7" brand new. In real world, I don't readily detect the differences. I know the odometer is off and at higher MPH, it goes off but it isn't so obvious for me to give it a second thought.

With the metered/radar posted streets, what flashes on the display matches what I have on the speedo. La Palma set's one out and the stretch from San Luis Obispo has one to and from Morro Bay.

ychachad

Taller sidewall does not necessarily compromise handling, if the aspect ratio is kept the same, which is what I have done.

Leatherseats.com

Rotational mass is actually a lot higher than just adding the overall weight difference between two different wheel and tire packages. I believe the rough equation for unsprung or rotational mass is about 4 times the actual weight number. So while someone might an overall of 20 pounds in their new wheel and tire package then the curb weight is just an additional 20 pounds, but the rolling weight and actual weight is going to be somewhere around 80 pounds. The same applies for brake discs. Big brake kits are awesome, but they can add some serious weight.

This was demonstrated very well when the Dinan M5 and a supercharged M5 ran together. The Dinan kept up and I forget if he ended up winning or not, but all that Dinan did was some bolt-ons and lightweight mods. The supercharged M5 had all the bolt-ons, supercharger, and aftermarket wheels. It was really an impressive sight. I think one of the figures was that Dinan had dropped the actual rolling weight of the vehicle buy like 160 pounds (40 curb weight pounds) by getting some ultralight wheels and brakes. Anyways... if you are worried about performance at all than big heavy 22's isnt the answer for sure.