Hi,

It could be a stupid question but I had kinda weird SLP warning light blinking issue right after 20" wheels installation.
The thing was, the local america's tire recommended me to put same sizes of tires/wheels(245/35/20 - Front and Rear) around and they put 4pieces of exactly same size wheels and tires which was not recommened by infiniti dealer.

Just right after installation on my 03' G Coupe,
the SLP light started to blink and it automatically slowed car like 5 minutes.

I drove back to tire shop to ask and the crew said, the ECU might need to be adjusted to new rim size and stuff so after around 20miles of drive would solve this issue.

After 10miles of drive from the tire shop to work, the SLP light stopped blinking but I'm still wondering if there's anything I have to do to make it sure like ECU reset and such.

Infiniti dealer still strongly asks me to go back and replace the front tires with smaller ones than rear ones but america's tire guys keep saying everything is going to be fine after a short drive.

Don't know what am I supposed to do.



Anyone?


Thanks in advance.

 

I made an appointment tomorrow morning at local america's tire for replacing rear tires.
Front is Kumho Ecsta SPT 245-35R-20 95Y
Rear will be Falken FK 452 275-35R-20 102Y
Hope it will solve the issue. Sigh~~

 

That's closer. You need to keep the relative diameters the same, and the rears were always larger diameter than the fronts. Let's see, those fronts will be 2.51% larger than stock and the rears will be 3.12% larger. It will throw off your speedo, but I think that as long as they're both about the same relative size difference, which they are, they won't throw VDC warnings. Hope it works out.

 

Thanks for your comments, Curt!!
My only concern is, whether 275-35-20 tires work with 20X8.5 Offset 20 wheels or not. I have same size rims for front and rear so there is no choice for now. Hope I don't need any spacers or something for rear. (Yes, I'm a total noob to wheels&tires. )

 

When i went from my after market wheels back to my OEM 18 inch wheels i had the same problem but it went away.

 

I believe the stock height of the rear tires are 26.8, and the fronts are 25.7. So, if you keep the diameters around the same with a smaller side wall, you shouldn't have any problems.

I used 4 of the same size snow tires for winter, all 225/55/17. They are approximately the exact same diameter as the stock rears. I only had the slip light go on once the first time I drove the car, and it never happened again.

 

Thank you very much for your comments.
Like you guys said, After about 30miles of drive, SLP light went away.
I drove a little aggressive to make it sure and everything looked fine.
Went to Local America's Tire and they said, just give it a try for a couple of
days and if there's anything I still don't like, they would replace the rear tires with 275 without charging re-stocking fee and such.

I still don't know if it's a good choice or not but I think at least I have an advantage for tire rotation if I keep the same sizes of wheels but if there's any mechanical / performance issue, I wouldn't hesitate to put some more money on the rear.

Again, thank you for your comments.

 

I'm glad things have "worked out" for you.

However:

1. Your tire set up is rediculous. Talk about destroying the dynamics of the car. Also, isn't a 35 profile too much for a 20" wheel? My 19s are 35 profile with 245 front and 275 rear. Your wheels and tires must look huge.

2. Next time before you spend your hard earned money to screw up your car, ask some questions here, do some research. I'm sure that you would have received plenty of help so that you didn't make this mistake.

Can you please post pictures--I have to see what this looks like!!

 

Thanks for your concerns and comments, JZ39.
Yes, I should have asked some more questions before I "screw up" my car but, I think I still have some chances.

Like you said, the tires + rims look HUGE. On the top of that, since the front / rear has exactly same sizes, the front ones somewhat look a big bigger than rears(YAY!! totally un-balanced look)

I think I have to ask you some question this time to make my last chance on this Friday actually "works out".

I don' think I can replace the whole tires with lower profile ones but the only choice I have is replacing rear tire with 275/35/20 102Y Falken FKs.

Will there be any problem with clearance for brembo/fender well(inner&outer)?

The current rim is 8.5 wide + 20 offset. Can it hold 275 tires without any issues above?

Any info will be totally helpful for me to avoid Re-screwing-up my lovely G.


Again, Thanks.


- JK -

 

I don't know. Honestly, before I spent more money, I would take on the tire place and ask them what in the hell were they thinking making this suggestion to you. They are supposed to be experts:

They:

1) Sold you incorrectly sized rims front and rear
2) Sold you tires that are way off from the rolling circumference of the OEM set up which will also whack out your spedometer
3) Perhaps dangerously suggested the same sized tires front and back


I apologize for being an A-hole in my last post.

 

Having the same size tires front and rear is not necessarily dangerous. You are eliminating the "stagger" set up from the factory. As long as you do not go outside the recommended tires sizes, ( so not to mess the VDC up), you will be okay.

Most that will happen is it throws the speedometer off slightly, and your car is more neutral than before.

Believe me, there are many people on this forum who no longer run a stagger set up.

I would still biatch at the tire place like JZ39 said. They should have sold you a comparable set up as OEM, and larger rear rims to fit the setup

Good luck

 

It's not a good idea to put a 275 on an 8.5" rim. Offset makes no difference as the tires are mounted in the same place no matter what the offset. The width is the only thing you should be concerned about...and in this case, a 275 is too much. Many tire shops won't even mount such a wide tire on an 8.5" rim. You could probably go with a 265, though even that is pushing it.

The reason the front ones look bigger is not because of the diameter or the width, but rather because of offset. If you want the rims to be flush all around, a higher offset is usually necessary on RWD cars. It's why the factory 18" rims look more sunken in the rear than they do in the front. (They are the same width and offset all around.)

Also, in my opinion, running the same width tire all around isn't necessarily dangerous. There is a slight safety concern, yes, and I'm sure that's why Infiniti told you to run a smaller tire up front. The reason being that running a smaller tire up front will create understeer on these cars, and for the average joe, understeer is much easier to control in a no-traction situation than oversteer is. But if you live in an area where you have no snow or otherwise won't be losing traction very often, it's not a big deal.

Edit: Looks like the previous poster beat me to that last part

 

JZ39, No problem at all. Your comments really really helped me out. Thanks.
GR8TG35, Alteus, Thanks for your info. I learned a lot from you guys. I'm pretty sure that I am not gonna make a same mistake again. I feel like I'm kinda armed with solid wheel / tire knowledge now. YAY!!

Actually, I live in Sunny So. Cal. and normaly rent a car when I go snowboard and not a hardcore commuter at all(like 20miles a day on notorious I-5).

Well... like I mentioned above, the tire shop guy let me try it out for a couple of days more so maybe I would ask him to replace the rear tire with 265 or replace front tire with smaller one(not quite sure whether go with 225 or what.) or just keep this settings until it hits the time to change the whole.




Hope my stupidness will help some of SUPER NOOB on wheels/tires people through this thread.


I don't think I can thank you guys enough and thank you G35 forum.



cheers!!


- JK -

 

by using the tire calculator from America's tire. the 245/35/20 is about stock settings. except for the rev part.

i would just stick to the size you have now. since the slp light went away.