[AttAkker]

I searched and the subject is touched on but not definitive. I need new rear tires and since they need ordered I was wondering if I can get away with a little wider size? Maybe just from 265 to 275. The sales tech didn't know the answer because of course Maserati isn't a common car.

Thanks.

 

[The Head]

what is the width on a GS rear wheel?

 

[AttAkker]

Rear 19 X 9.5

 

[DeaneG]

We heard from a couple of forum guys that said 275 on the rear is no problem. 275's are at their fitment limit on the 9.5" rims, but I expect they'll look better rather than being so stretched over a spool.

I plan to go to 245/275 on my GS spyder this summer.

 

[AttAkker]

Great, I guess I will give it a go. will post before(265) and after(275) pix

 

[xraygun]

I hope it will also give the rim some additional protection from road hazards. Please let us know your impressions on changes in handling and ride as well!

 

[GCalo]

You should use this tire calculator first to see what is the appropriate difference to equal the OEM tire diameter: http://www.miata.net/garage/tirecalc.html

Then knowing the appropriate tire size go to a manufacturer's table to see the suggested rim width. For example: http://michelinman.com/tires/

No guessing and you'll know for sure.

This way you get larger tires and don't affect gearing or speedo readouts.

 

[maseratikai]

sites are useful, but how does one ensure larger tire fits our rim sizes: 8.0"J front and 9.5"J back? any sites who can help with that?

 

[The Head]

your closest size to accurate that will fit on a 9.5" rim is a 275/30/19 which will cause your speedo to read .6 of a mile fast at 60

the closest you can get to factory is a 315/25/19 which only reads .2 of a mile fast but you need a 10.5 to 11.5 in rim to hold them

go into specs under a given tire in tire rack and you can find the recommended rim width for any tire

 

[haha]

your closest size to accurate that will fit on a 9.5" rim is a 275/30/19 which will cause your speedo to read .6 of a mile fast at 60

the closest you can get to factory is a 315/25/19 which only reads .2 of a mile fast but you need a 10.5 to 11.5 in rim to hold them

go into specs under a given tire in tire rack and you can find the recommended rim width for any tire

though anything beyond 295 is mathematically impossible for our cars...too wide.

 

[AttAkker]

I hope it will also give the rim some additional protection from road hazards. Please let us know your impressions on changes in handling and ride as well!

I will keep you posted.

 

[GCalo]

sites are useful, but how does one ensure larger tire fits our rim sizes: 8.0"J front and 9.5"J back? any sites who can help with that?

Once again, after you have determined the tire size you'd like to achieve, look at the tire manufacturer's site for that exact tire and it will give you rim widths optimum for the tire!

 

[flashgordon]

Wider Tires

I contemplated doing this with my Spyder (e.g. going to 245F/ 275R). They will fit but only with certain tire brands. The way to check is to use the tire size calculator to find a size within 2% of the diameter then check if that size (in a specific tire model) will fit the rim by going to the manufacturers web site.

I stuck to the stock size because I had several tire guys tell me that going to a larger size will result in a higher degree of sidewall flex thereby affecting handling (for the worse). This makes sense because the tire is actually bulged out over the rim a bit (I have this problem on my G35 where I switched up from a 215 to a 235).

 

[DeaneG]

I am actually looking for that additional sidewall flex. Roads are rough in my neighborhood and I'd gladly give up a little handling for a little smoother ride. Particularly in the Spyder, where the cowl shake reminds me of one of the few downsides of my automotive choice at every tiny bump.

 

[GCalo]

Post the standard sizes and I'll run the possibilities.

 

[The Head]

though anything beyond 295 is mathematically impossible for our cars...too wide.

it is all a matter of wheel offset...I have 19 x 11 rims in back which matches up to a 315 nicely given I have the wheel room I will most likely have the tire room too

 

[maseratikai]

for the GS: OEM tire and rim sizes are:
Front: 235/35 ZR19 8.0"Jx19
Rear: 265/30 ZR19 9.5"Jx19"

 

[GCalo]

for the GS: OEM tire and rim sizes are:
Front: 235/35 ZR19 8.0"Jx19
Rear: 265/30 ZR19 9.5"Jx19"

You are a bit limited on the fronts unless you went to a more positive offset rim or spacers and had the fenders rolled. So, you could go to 245/35-19 w/o problems.

For the rears you could go to a 275/30-19 with no problems. A 285/30-19 would fit but your speedo would read about 61.1mph at 60 mph. You could fit a 315/25-19 but you'd need 12" rim with a bit more positive offset.

Knowing these figure look up Michelin PS2's or Pirelli P Zeros and see what they recommend for a rim width for these tire sizes.

You do have limits to keep the OEM rims, however.

 

[DeaneG]

I just checked my tread, I have only 2.x mm at the right rear so I'll be in the market sooner than expected.

Wonder what I could have done to that RR tire, the others are 3.x-4.0 mm. Maybe I accelerate up left-hand onramps much harder than right-hand. The car otherwise tracks and stops absolutely straight.

It looks like RE050 Pole, PS2, Pzero, Eagle GS-D3 are all reasonable choices for 245/275 fitment at tirerack with different handling / noise / hydroplaning tradeoffs.

 

[AttAkker]

265 vs 275

Ok, Got the 275 PZ Rosso replacements on. Look wise not much of a difference actually. However, ride wise is much improved. I am thinking only because the rears were so bald, I was feeling everything. The "Sport" mode ride is much better now. I only have like 20 miles though. I am driving it to work tomorrow so I will report back. Here is the 265 vs 275. Sorry I didn't get the angle exactly the same..

No comments on my kitchen floor tile garage. hehe it was a test and I can't wait to tear it up. Bad idea.