Daytona Blue Z in Bo

I live in Boston and driving on the stock tires as been to say the least scary this winter (and last winter). My rear tires have at most another 5000 miles in them before hitting the tread replacement line.

I am looking for a High Performance all season tire for the rain and cold weather and I don't want to change tires in the winter either and something grippy enough to get me moving on the 1/4 track, I narrowed it down to the Michelin Pilot Sport A/S -->
http://michelinman.com/catalog/tires...etype=3&tire=2

Handling rating is a 9
Wet traction is a 10
Snow traction is a 8
Treadwear is a 7

Anybody have any experience with these tires or can anybody reccomend something better? I am looking for at least the same grip as the stock tires with an all season rating.

Also how wide can you go on the stock 18" rims? I'd like to get a 265\45 18" if thats possible..

Static

I know that you can't put a 265 on the stock wheels.. they are only 8" wide.. and that size of tire will not fit.

Daytona Blue Z in Bo

Ya I just sifted thru 8 pages of search finds on tire sizes and I think I am gonna go with 255/45 18's on the back and 235/45 18's on the front..

onecoolee

why not go with stock sizes ? Michelin makes the Pilot Sports in the exact sizes or sizes very close to the stock Re040 Potenza rubber.

You can get P225/45R18 for the fronts and P245/45R18 for the rears in the Michelin Pilot Sports, but for hte A/S version, I think you have to get P225/40R18 in front and P245/45R18 in back.

They use the Pilot Sports on the stock G35 coupe, so I know they make exact replacements ... you may have to amke minor changes to be able to use the A/S Pilots.

Daytona Blue Z in Bo

I just want to go a tad wider with my tires, gives me the feeling of an upgrade rather then just a tire replacement.. Also better tires and a smidge wider may help my 60 foot times at the track

MikeStevens

Is there any reason you can't put the same tire on all four wheels? On the 04 Touring the wheels are supposed to be 18X8 all around.

MannishBoy

iTrader: (1)

If you put the same size all the way around, it will most likely mess with ABS and VDC. The computer makes calculations based on the diameter of the tires, and it knows that stock there is a difference between the fronts and rears.

It's probably OK for track events, but I don't want to do something like that on the street.

MikeStevens

Sorry, I left out some information.

For my Touring, the fronts are 225/45-18 and the rears are 245/45-18. The difference is in the width of the tire, not the diameter.

I'm trying to find out what the objective is in the different widths. I've read a vague reference to the smaller width being aimed a steering control, but for a daily driver I wouldn't think that's a big issue (especially with only a 20 mm difference).

It'd be nice if swapping to the same tires all around means I can now rotate the tires front to back.

uro279

Goal is to keep diameter stagger as stock. I don't agree with what some folks are saying that to eliminate the stagger is 'O.K.' as long as rear is not smaller than the front.

Think about it this way: The car was designed to handle with a certain stagger. Much planning and engineering was made to make EBD, ABS, TC, VDC, weight transfer, and so forth to handle with that stagger. However, they have to make a certain amount of 'comprimise' not to go too much in one direction or the other so as not to disrupt the 'balance' that would keep MOST people happy.

However, people are different, and want different things. So if your a track guy, the current set-up may not be aggressive enough for you. So you can make changes to improve the handle/track performance, but you lose other things in the balance.

So you have to know exactly what trade-offs may occur prior to making changes to see if your willing to make those changes. This requires a good knowledge base of understanding about your car and knowing what your doing.

Thes are a couple of questions to ask yourself prior to making changes:

How will this affect the cars electronic brake distribution? Will the weight transfer change and, if so, what will this do to the brake bias? How will the VDC/TC react? What about ABS? Will it tend to understeer/oversteer? How will the change match up with my style of driving? Will it be a safe set-up?

These are just a few questions, but their are alot more I'm sure.

It's ultimately about how much risk your willing to take and who your are. Just know what you want before hand, learn how to make those changes and what the comprimises are, be honest with yourself if your willing to make the trade-off with the risks involved and if you, and finally if you can be happy with your choice.

lowrider

iTrader: (3)

IMO, replace with 245/40/18s in the front and 255/45/18s in the back. Thie 245/40s are exactly the same OD as stock and the 255/40s are only .4" bigger in the OD (.2" higher). The stagger will be maintained, the understeer will be greatly eliminated and the handling will be improved. These sizes will fit the stock 8" wide wheels, and will give a better look also. As far as brand, I think the best performance/cost ratio goes to the Dunlop SP9000s. A great performance tire.

Lou

ares

iTrader: (2)

"I am looking for a High Performance all season tire for the rain and cold weather and I don't want to change tires in the winter either and something grippy enough to get me moving on the 1/4 track"

lolcontradiction

sorry man, but that is not gonna happen. your gonna maybe improve over stock, but overall any tire that can do anything will be mediocre at everything.

no way a 255 tire is going to have any chance of cutting through snow and getting to the pavement, any tire thats soft in the winter will fall to peices in the summer.

get summer tires, and use them only for summer, then in the winter get blizzaks and use them only for the winter. keep your summer tires and remount them on the other side when the following summer comes around. a set of tires will still last its full life, say you get 30,000miles on a set, you could use them year round and get 3 years or whatever, or use them half the year and get 6years between 2 sets. same difference, but youll have better performance at all times.

lowrider

iTrader: (3)

ares

You're right. I didn't read his understand his whole post. Separate summer and winter tires are a must for his application. Winters would probably be better on a 17" wheel, which he should be able to find at this forum for less than $400 for a set.

Lou

Daytona Blue Z in Bo

I went with 245/40/18s in the front and 255/45/18s in the back, Michelin Pilot Sport A/S.. All 4 tires installed, balanced + tax was $1050 done by a friend of mine at his tire shop with no charge for labor..

Traction has greatly increased in all weather, expecially in temps under 20 degrees where the stock tires were a bad joke. I havn't seen snow yet but i'm sure they will be 100 times better then the Potenzas.. My G-timer 2 is showing me consistant 60 foot times around 2.10-2.15 on easy launches so i'm sure 1.9-2.0 is easily do-able at the track.

Also I just got the Borla TD installed, that plus tires and my goal this year is 13.8 at the track. The new tires are soo much more forgiving to launch..

Thanks for the help guys!

MannishBoy

iTrader: (1)

I think you are missing the point. The aspect ratio is a function of the tire width. I think it is a percentage of height of the sidewall based on the widest part of the tire. So, a 45 on a 275 width is taller than a 45 on a 225. They aren't seperate things. So, if you go to a 275, you'll probably go down in aspect ratio.

Here is a tool to show that:
http://www.miata.net/garage/tirecalc.html

MikeStevens

Yeah, of course you're right.

I just need to go do the analysis that gets them to "close enough". The whole thing will to focus on maintaining the height, (axle to road) as the spec calls for.

There must be some leeway since a tire 5mm out of diameter spec is probably not as bad a an underinflated one, on the cold/hot spectrum.

Thanks for the ideas.