^^ I guess this would be the best bet 225/45R18 91T or 225/55R18 98T. But which one, I know the middle # is some ratio of height vs inner width. The brand has 45 or 55 but no 50....lol

 

ok they are the same width different height on the side wall. 225mm wide at the equator and one is 225mm*0.45= 101.25mm in height

225mm*0.55=123.75 mm in sidewall height.


So now which one will fill the wheel well better.

 

I'm sure the 55 would fit, it's only 2.2 cm, that's less than an inch taller

 

2.2cm on the radius so 4.4 in diameter

 

If it fits go taller an skinnier better in the snow

 

My winters are 245/45/18's all around.


(PS: i know multi posts but i was trying to break the 1000 post make wooohooo)

 

DO NOT use either choice. 225/45/18 or 225/55/18 is over 3% different in rolling circumference than OEM spec (225/50/18). That could potentially throw off the sensors of the onboard computer ... (ie ABS, traction control, etc) ... which could put you in danger.

Whomever said to pick the "taller" one ... that could be a very dangerous situation. Don't advise people if you're not sure what the numbers mean and the ramifications of those choices. "Filling in the wheel well" is not the important thing here ... safety is.

 

^^ thanks for the heads up, but damn, this model of tire is not made for our size.

 

wanna check again about the rim and tire size for G37S.. if 17" is no go here.. please give me proper size

 

Any good tire shop will tell you what will work with your car. If you read my posts i say what set up I have and mearly stated a taller tire will be better in the snow I never said what size to use. As for safty if you have no rubbing issues it wil only through off your speedo a bit. And yes I do understand what tire sizings are I have worked at Michelin for 5 years building and classpecting tires. My wife worked there for 6 years building tires on the chain (MAF). As well both my father and father in-law have over 70 years combined at the plant.

 

I was asking because I already had put larger size tires on my cars before.

 

Can you please elaborate further? Does it really affect the onboard sensors that much?

225/50R18 vs 225/45R18 is 3.3% difference according to miata tire calculator (i.e. when speedo reads 60mph, actual speed is 58mph).

 

^^^ exactly it is not a big deal.

 

Is it actually written somewhere - that says OEM spec is 225/50R18 for snow tires for a G37S? Or is this just because tirerack.com says so? Because an Infiniti dealer told me that Infiniti says that 225/45R18's in front and 245/45R18's in rear is the proper size for snow tires since the Sport model is a different set-up then the regular G37. The regular G37 should use the same size all around - whereas the "S" should use staggered (according to Infiniti dealerhip)...

 

^^ what's the point thought, putting wider tires in the back for winter tires. do the 225/45/18 fit in the rear?