Tire size advice needed........

[gsarmed]

Hello folks. I need to replace the stock tires on my 04 S. I am leaning towards the Dunlop Direzza Sport Z1 Star Spec. As we know, the stock tire sizes are 245/40 rear and 215/45 front . After speaking with a rep at the tire rack, he suggested I get the 255/40 rear as the stock OEM tires are "wide" for 245's. My question is this, which tire size combo for the Dunlops should I get and why?

255/40 rear 215/45 front OR 255/40 rear and 225/45 front?

The car is primarily only driven hard on the street.

Ant advice is much appreciated.

Thanks!

[smac2K]

Go to the home page, and in the search box type "tire" or "tire size" or something like that...Trust me - you will get more info than you can handle :yep: ;)

[gsarmed]

Thanks. I may have missed it but I did try that first and could not find a post about what tire sizes to choose and why.

[smac2K]

Here are a few threads for ya...:thumbsup:


http://forums.s2kca.com/showthread.php?t=23813

http://forums.s2kca.com/showthread.php?t=10300&highlight=tire+size

Read this :below:
http://forums.s2kca.com/showthread.php?t=8244&highlight=tire+size

[repiv]

I think the guy at TireRack is confused. He's thinking of the AP1 OEM SO2 tires. Those rear tires were designated 225 but were the approximate tread width of any other brand of 245. That's why Honda went to 245 when the AP2 went to 17" sizing. The AP2 245 IS a 245. However, what people have done till now is to go with 225/45/17 in front and 255/40/17 in the back. This gave them the same stagger that was designed into the S2000 and the "upsizing" gave the exact same tire diameter that the AP1 was accustomed to.
Along came the AP2. It came from Honda with 215 front and 245 rear. This best approximated the width and stagger of the AP1, which the suspension was designed for. Bridgestone made the SO2 specially for the S2000 and made it with a blocky tread to sidewall configuration so that it resembled a 245 tire. However, Bridgestone did not do the same for the AP2, thus necessitating the OEM sizing that appeared.
Then along came the CR, which had 215 front and 255 rear. Honda did this to suit their desired handling parameters better - less oversteer. The CR was designed and suspended for those tires. If you wish, you could also go with 215 and 255 but your car wasn't designed for it. Nevertheless, it can still be done. For a non-CR S2000 that isn't lowered, I would still recommend 225 and 255 as the better combination. Of course, the ultimate choice is yours. 215/245 or 215/255 or 225/255 will all work. Each one will give a slightly different handling characteristic.

[gsarmed]

Thanks for the information. Very helpful. Could you describe what the expected handling characteristics of the different combinations would be? Is there any downside in deviating from what the Honda engineers selected for stock? Or any upside to deviating? Thanks allot.

[repiv]

The wider the tread width, the more rubber on the ground and the more grip on the road. The more grip you have in the front, the more tendency for oversteer. The more grip you have in the rear, the less tendency for oversteer. This would be the handling reasons for selecting any given combination.
Then there's the esthetic reasons for choosing a particular combination. People tend to choose a wider tire for looks. If this is important to you, then you make your decision based on appearance.
Some consider the stock S2000, both AP1 and 2 to have inherent oversteer naturally, while others consider it to be perfect as it is. You must decide what you think of the way your car handles and choose tires accordingly.

[Skakum]

I'm running 18" wheels all around and my fronts are 225/40 and my rears are 265/35. I've noticed a huge difference in handling and stability when it comes tracking the car.

[repiv]

I'm running 18" wheels all around and my fronts are 225/40 and my rears are 265/35. I've noticed a huge difference in handling and stability when it comes tracking the car.

This introduces an interesting principle that should be elaborated upon. For the OP, your available tire size options is limited by your stock rims. You really shouldn't go beyond a 255 size for the rear rim. Otherwise, you will be unduly stressing the tire by having to force the bead out further than it was designed to do and still be able to withstand the stresses put on them from whatever manouvers the car may make.
Having 18" rims and a lower aspect ratio will give a much stiffer sidewall and this alone, will increase lateral strength and firmness in extreme G loads. The wider rear tire width also will reduce oversteer tendency further. So, for the OP, assuming you are using the stock rims, Skakum's choice is not an option for you.

[tomauto]

I'm running 18" wheels all around and my fronts are 225/40 and my rears are 265/35. I've noticed a huge difference in handling and stability when it comes tracking the car.

Still can't keep up with my ap1 rims in the twisties :poke: