Todd@ProDyno

Oh boy....Ive been over this again and again. Seems as if these shops that 'know everything' really dont know much at all. Most common is found in 19" upgrades when some random shop suggests 245-35-19 with a 275-30-19 rear. THE REAR TIRE IN THIS SITUATION IS SHORTER!

1st issue:
Nissan wants between .5 to .75" stagger front to rear, rear being taller of course.

2nd issue:
you WILL anger vdc, trac, abs

3rd issue:
The dealer doesnt need much reason to try and void your warranty. Ignoring their stagger rule is one thing, doing a rear tire thats shorter is even worse.

4th issue:
It looks wrong. a 275-30-19 rear is 1.2" shorter in overall diameter than your stock rear tire. Why would you do this?

For most 19" 350 applications you should have a 245-35-19 & 275-35-19 or 285-35-19 rear tire. Anyone who tells you otherwise is mistaken. the 35 series rear may be a bit harder for them to find, or maybe they were told the wrong information. Either way, it is the incorrect setup...and a lot of you on the board have had this mistake happen to you.

Maybe it will cause and issue. Maybe it wont. I sure wouldnt want to find out while going 60 on the highway in the rain in CA when a wrec happens around you and your abs decides to freak out. Just my .02.

Take a look at the calculations below.

this one is stock size rear vs a 275-30-19 rear


this is the 245-35 & 275-30-19 incorrect combo


and here is the correct 245-35 & 275-35 combo




Most commonly 18" upgrades should be
245-40-18 with a 275-40-18 rear

and in 19" it should be
245-35-19 with 275 or 285-35-19 rear.


TIRE SIZE CALCULATOR

zxsaint

I've got an incorrect stagger as well, but not as bad as 275/30.

While I haven't run into any problems yet with 245/35F and 285/30R, i'm going to correct it with my next set. I'm considering 255/35/19 and 275/35/19 instead. That still provides for a .55 stagger (only .16 less than stock)

Wish I could do 285/35's in the rear but tire selection in that size on 19's really blows.

fdao

Very informative post. Thanks.

Question: What would you recommend for a Plus 0 set up on 18" Track Model Rims?

onii

iTrader: (1)

thanks soo much for this. i was lookin for over half an hour yesterday tryin to find this info.

Audito350Z

iTrader: (1)

I run 245/40-18 front and 255/40-18 rear on my Track model wheels... I don't remember the actual numbers, but that set up is close to OEM dimensions

PeteH

ChuckGZ

all right, guys. time for chuck's stupid ? of the day:

If you go up in size from, say, an 18' to a 19', how do you compensate for what your speedometer is telling you vs. your actual speed? any way to adjust for this?

All i ask is that anyone who posts telling me how dumb this question is also provides an answer.

lowrider

iTrader: (3)

Since the whole idea here is trying to keep the Outside diameter at or near stock, there will be no speedometer error to correct. With the 19" you will have a shorter tire sidewall which will compensate for the taller wheel, and therefore have the same outer diameter.


BTW, the correct plus 0 setup for the stock 18s is 245/40 in front and the stock 245/45 or 255/45 in back. 255/40 is too short, and might affect the stagger.

Have a nice day.

Lou

ChuckGZ

Ah. Thanks for clearing that up. I'm a knucklehead when it comes to wheels/tires.

moog

iTrader: (14)

What would you recommend for my G35 which runs 225/40-18 & 245/40-18. I will be upgrading to 20"s in a couple weeks.

Audito350Z

iTrader: (1)

I used 255/45 for a while and the rear tires looked like 4x4 truck tires... while that size is the closest to the OEM size, it is actually a tad taller than OEM, by about 1.2% IIRC. The taller tire also made the car slower on the straightaway at Texas World Speedway due to the change in the gearing created by running a slightly taller tire.

The 255/40 is shorter than OEM, but only by about 2%... not enough to cause any negative effect... the accepted practice is to remain with +-3% of the OEM diameter....

PeteH

fdao

Thanks PeteH

Todd@ProDyno

Since it came up in a different post, Ill try to address it a bit here as well.

Nismo upgrade is 245-40-18 & 275-40-18 which is a .94" difference in height front to rear. Outside what Nissan originally told us, but not too far off. However, Nismo follows up with a disclaimer saying not for VDC cars. Then, they get even more confusing and say if you use the full Nismo suspension, its ok to use this with VDC. Oh man Im confused. That makes no sense at all, and I cant wait to hear an answer. The suspension has absolutely NO way of effecting how the ecu is reading the tire revolutions which is the #1 reason for vdc, abs issues.

lowrider

iTrader: (3)

I'm running Nismos with 245/40/18 and 275/40/18 (Dunlop SP9000). The Dunlops came from Discount Tire here in Tucson. There is absolutely no problem with VDC, TCS or any electronic system. Nissan's disclaimer is pure BS. Sometime back, I heard that they actually withdrew it. Anyway, I love the wheels and the tires, and the handling is outstanding!

Lou

craZy

Hey all,

Just out of curiosity, what would be a good size to run with a 19x9.5 wheel in front and a 19x10.5 rear? I have a base model, so I dont have to worry about some of the malfunctioning electronics. But I am concerned with the ABS issue and do not want to stretch a tire over these wheels. I can not figure out what the correct sizing would be for this setup, so can someone please help me??? Thanks in advance folks....

Jerry

lowrider

iTrader: (3)

I don't know what the offset is on your wheels, so I don't know if you would have rubbing issues in front or not. But, IMO, the correct size tires for those wheels would be 275/30/19 in front and 285/35/19 in back. I don't think you'd need to roll the fenders, assuming the offset is correct. I believe only Continental makes tires in those sizes. Good Luck!

Lou

zxsaint

craZy, i've got the same sized wheels. The ideal setup for this would probably be something like 265/35/19 and 295/35/19 but rubber this size is expensive and hard to find.

My next set of tires are going to be 255/35 and 275/35 since I really want to get the toyos (light weight+excellent grip).

Daewoo

I am in the same boat as craZy. 19x9.5 wheel in front and a 19x10.5 rear. what tire offers this size other than continental.

DmitryZ

lol

You shouldn't have any vdc abs problems as you are running the nissan suggested size on the nismos as first post suggests

You will definitely screw up your vdc abs if you have-
smaller rears than fronts as mentioned by discount tire in first post-> more brake bias to the rear = very bad


P.S.

Those are some hot wheels!!! I am getting them installed next week on my Z (same tire sizes)

sux2bu

DTD,

I am receiving some conflicting information on the correct tire size for a 19x8 wheel. I have been told by some that 245/35/19 is appropriate, while others have said that 235/35/19 would be a better fit. What would you recommend?

Todd@ProDyno

Both are fine for an 8" but Id go 245 for your application