JETPILOT

iTrader: (51)

Why does it seem the most popular plus sizing for the 350z is a 245 35 F and a 275 35 R. When 255 35 F and 275 35 R is closer to the original tire diameters, and this keeps the orginal 20mm width difference between F and B. Going with a 30mm width difference will add to the understeer already present.

Will the 255 fit on the front without rubbing??

If I'm not incorrect doesn't the 245 35 F 275 35 R go against the .50-.75 inch maximum difference in tire diameter between front and rear?

JET

King Tut

iTrader: (1)

Why do some people not realize that there are 2 different OEM tire setups for the 350Z? One for the 17" wheels and one for the 18" wheels. Why do people not realize that when listing tire sizes they should also list rim diameter for the tires they are talking about? You talking about tires for 17", 18", 19", or 20" wheels.

Gary King

iTrader: (19)

Go to the Correct Tire sizing when changing wheels... thread.

JETPILOT

iTrader: (51)

19" wheels....

I looked at the correct tire sizing post. Thats exactly why I posted my question. They recomend the wrong tire sizes.

JET

Gary King

iTrader: (19)

Did you use the tire size calculator?

JETPILOT

iTrader: (51)

Yes I used the tire size calculator...... and if anyone else used it u would see that the 245 35 19 275 35 19 setup they recomend is incorrect. Thats my point. and the 245 35 19 275 35 19 setup they recomend is even worse.

JET

Gary King

iTrader: (19)

What makes it incorrect?
What are you comparing to?
How can two identical things have one be worse than the other?

JETPILOT

iTrader: (51)

Im an idiot... I intended to say that the 285 35 19 they recomend is even worse.

Ok here it goes… there is a max difference in diameter in the 350 z between front and rear of .50-.75”.

Stock Front 225 45 18 = 25.97 diameter
Recommended Front 245 35 19 = 25.75 diameter

Stock Rear 245 45 18 = 26.68 diameter
Recommended Rear 275 35 19 = 26.58 diameter

26.58 – 25.75 = .83 out of limits

My recommendation is as follows

255 35 19 = 26.03

275 35 19 = 26.58

26.58 – 26.03 = .55 within limits

Now to mention the 20mm difference in width which is the same as factory as opposed to 30mm width with the recommended size which will increase understear.

The 285 rear recomended is even worse in diameter, and difference in width.

Didn’t anyone else do the math?

JET

ttsupra94

iTrader: (1)

It really could matter less. The general idea is to try and keep it close to the .5-.75 range which the 245, 275 setup does, we are talking about less than a tenth of an inch. You will see all kinds of setups that make no sense like people running rear tire setups that are shorter than the front setup. Best thing to do is go with that you think is best. Most people like the 245, 275 cause its adds a little more stagger. These sizes are run on most of the setups on here. I am actually thinking about changing my front to a 255/35 and my rear to a 305/30, but i'm not sure yet.

King Tut

iTrader: (1)

You said it not me. You never read my first post. WE DON'T ALL HAVE THE 18" WHEELS, so your math doesn't even cover the whole story. I have also done the math. The math says THE COMMON SETUP CAUSES NO ILL EFFECTS TO THE TCS/VDC AND THE TIRES ARE MORE COMMON AND THUS MORE AFFORDABLE. THAT IS WHY WE USE THEM. THE END. If you want the 255/35/19 tires then go with them.

JETPILOT

iTrader: (51)

The post on the board by DISCOUNT TIRE DIRECT gives SPECIFIC sizing information which is wrong. There is no GENERAL IDEA as you said. It's either right or wrong. And their recomendation is wrong.

TSC/VDC..... I don't care. Can you spell understear?

I'm not intersted in who has 18 inch wheels and who doesn't. Im discusssing the 18 inch application.

The whole point here, which you dont seem to get is that the RECOMENDATION is that people run the OPTIMUM plus sizing of 245/275 which is incorrect in any rim size. THE CORRECT PLUS SIZING IS 255/275.

The SECOND point of my post which you also missed is the question of weather the 255 will fit the front.

Thanks for your constructive input......

JET

ttsupra94

iTrader: (1)

Thats why he was asking whether you have 17's, or 18's or what becuase they aren't all the same size wheel, so whether a 255 would fit or not woudl depend what size your wheel is. There recommendation is not wrong. It isn't a law that you have to be within the .5-.75 range, it is a recommendation. If it was so wrong, why does almost everyone on here have the setup. I can't think of anyone that has the setup you are describing, which should tell you something. I have had no understeer, oversteer issues with my setup. Regardless, i'm not sure what you are trying to do. Do you want someone to say you are correct, do you want everyone to switch to your setup. It really doesn't matter, if you want 255/275, go for it, it will work just fine.

Sorry, i already answered your question about whether a 255 will fit in my first post. It most likely should, but it all depends on your offset of the wheel and if you are dropped. There are people who run 275's up front. To get a solid answer to this question you need to tell exactly what wheel and what the offset is and you will get a better answer.

King Tut

iTrader: (1)

Thanks for your constructive question. Will 255s fit without rubbing on what??? On the stock 17" wheel. On the stock 18" wheels. On a 19x8. On a 19x9? On a 19x10? What about offset? What about lowering? There is no answer to your question because you didn't give any information. I don't think people realize that the difference between a 245 and 255 is like 10mm. That isn't going to determine whether it rubs or not. What will determine it is the width of the wheel and the offset. Oh yeah donn't forget to consider the amount of camber you are running cause that will also determine whether it will rub. I hope that was constructive.

Z BOY

iTrader: (41)

They are right, Jet. Your initial question was way too general and provided not nearly enough info about your setup to give you a helpful answer. That being said, after doing the research, i came to the same conclusion you did, and i'm gonna run 255/275 when my wheels arrive. Since my wheels are 18" i'll be getting 255/40/18f and 275/40/18r, which very closely approximates the stock diameter.
I don't believe anyone else has even tried this setup because at least 3 people, including you and i, have posted questions about the feasibility of this setup, and no one seems to know. So for better or worse, we will know the answer when my wheels arrive in 30-90 days or sooner if anyone beats me to it.

dnguyent

iTrader: (5)

I know I'm going with the 255/35/19 up front after my 245's feather themselves apart. I made the mistake of not specifying that I want 255's instead of 245's, and now my front tires look stretched (on 9.5" rims) beyond comfort.

JETPILOT

iTrader: (51)

@ stock ride height I am happy to report that the 255/35/19 w a 31 backspace, and a 275/35/19 w a 43 backspace works with no rubbing. The wheels I have ar SSR GT3's.

255/35/19, and 275/35/19 are the correct tire sizes if you want to get as close to the stock 18" diameters.

JET

DavesZ#3

iTrader: (26)

Apparently, you can't either - understeer.

Just kidding....

Actually, I'm glad you posted this. I'm looking at getting some new wheels and was wondering about tires sizing too. I see a lot of different recommendations, most of which don't seem to follow the rules. Maybe a lot of people are not using VDC so they're not concerned about the diameters.

Z BOY

iTrader: (41)

So how's it handle compared to stock, and any warning lights going off???

JETPILOT

iTrader: (51)

I have yet to see the limit of tire grip and I have pushed it pretty hard. I have the Michelin PS2's. I am sure the car will still understear but I can't even get near the limit. It's beyond my capabilities as a driver. Rear wheel traction is much improved with sticky 275 rubber back there. No warning lights. This setup is pretty sick. The car is more stable, and the stearing is not as quick. It was easier to toss around before.

JET

Z BOY

iTrader: (41)

cool. i love vaccuumming up those corners!