DetroitG37Joe

iTrader: (2)

I want to get a wheel and tire setup....20 inch Gold Volk GTCs...im thinkin 9.5 width up front and 10.5 in back...i dunno what kinda tires maybe Nitto 555s or something...gotta see what tires make em for the size..fat tires look good on our cars...i was wondering does anyone know the OEM tire widths on our Sport 19s with the Bridgestone Potenzas? I was curious as to how much width id be upsizing?

Also out of curiosity do we have more widths on our tires/wheels than do the basic 18 inch non sport wheels for the G37????


Lemme know guys!

TerribleONE453

yea our back rims/tires are wider. And our front tires are 225/45-19 and our rears are 245/40-19. And the non sport g37's are 225/50-18 all the way around

DetroitG37Joe

iTrader: (2)

I was wondering inch wise width......like 8.5 front, 9.5 rear etc....

GregUMR

You know, if you get 10.5 on the rears and somehow the tire/wheel combo is lighter then the stock sport wheel combo, would the car technically be faster and grip much better? I would think yes, anyone with more knowledge know the answer?

DetroitG37Joe

iTrader: (2)

Grip may get better - car stability and ability to stick to the road may get better however when you get bigger rims in diameter (eg +1, +2) the bigger the wheel the more it has to turn and the slower your car goes. Assuming you have Sport 19s, in the case of lighter 20 inch wheels - the lighter weight but added inch in diameter would at best even at and at worst the adverse effect of the inch would surpass the benefit of the lighter weight. Of course these changes in probably trivial anyway (.005 seconds give or take on your times)

About my question does anyone know what the stock widths on the staggered sport 19s are on our G's? My guess is 8.5 up front and 9.5 on the back but that is a GUESS.

SoCalOBG37

Yeah your right...8.5 front 9.5 rear

DiamondGCoupe

iTrader: (4)

Wouldn't recommend those Nitto 555s, haven't had good luck with them, they wear down just as quickly as softer tires.

gan78mao

iTrader: (1)

i think the stock tires are 8.5 and 9
coz from the stock tire size the front looks a bit stretched.
so my guess would be 8.5 and 9
i currently run 9 and 10

GregUMR

It's an easy formula guys.

Example: 185/60R14 85H or 185/60HR14

185mm x .60=111mm
111mm x 2=222mm
222mm + 355.6mm(14")= 577.6mm or 22.74"

The first number is the width of the tire in millimeters, measured from sidewall to sidewall. To convert to inches, divide by 25.4 In the example above, the width is 185mm or 7.28".

The second number is the aspect ratio. This is a ratio of sidewall height to width. In the example above, the tire is 7.28" wide, multiply that by the aspect ratio to find the height of one sidewall. In this case, 185x0.60=111mm or 7.28"x0.60=4.36".

The last number is the diameter of the wheel in inches.

To figure the outside diameter of a tire, take the sidewall height and multiply by 2,(remember that the diameter is made up of 2 sidewalls, the one above the wheel, and the one below the wheel) and add the diameter of the wheel to get your answer.



SO, 245 = 245 millimeters = 9.64566929 inches
225 = 225 millimeters = 8.85826772 inches

UNV-IT46

iTrader: (3)

this is not really correct. Just because you go up and inch in rim size you compensate for that by going small on the side wall. for instance a 20" wheel with a 25 side wall you would be at the same height as a 19" with a 35 side wall...

lowrider

iTrader: (1)

Close - Actually a 25 aspect ratio in a 20" would equate to a 30 aspect ratio in a 19" to be the same height (overall diameter). a 30 aspect ratio in a 20" would equate to a 35 aspect ratio in a 19" for the same height dimension.

Lou

lowrider

iTrader: (1)

See Page 389 (9-9) of your owners manual. Page attached

Lou

UNV-IT46

iTrader: (3)

ya i knew i was not exact with the number but the idea was correct

DetroitG37Joe

iTrader: (2)

good point UNV it could even out that way with the sidewall...thanks guys for helping me figure out them widths in such elaborate detail.....these simple lessons are reminding me of math classes i hated as a kid !!!!!!!

DetroitG37Joe

iTrader: (2)

Yo DiamondG - good call on the Nitto's...If I go +1 could u recommend me a good tire that gets good grip but lasts long too? I guess similar to the Bridgestone Potenzas we got on our sport 19s.....I am all about tread wear cause I drive a lotta city miles - lotta stop and go, turns, etc....