React3

Whats up guys, Im running Volk gt-7 245/35/19 up front and 275/30/19 in the rear. I used to run 235/35/19 but I upgraded to 245/35 . But when I change lanes hard or drive hard on the freeway my "SLIP" light flashes on and I bog down of course. With my old setup (235/35) I never had this problem, is this something I should be concerned with? But the car doesn't really slip I just think the computer is thrown off by the tire size..
Does this happen to you??
Can this be solved? By not changing back to 235/35.


Thanks

beggohbee

iTrader: (1)

I'm actually doing a lot of research into this right now and it looks like some people who run larger overall front diameters (vs rear) experience the same issue with the VDC system going a little crazy. The stock '06 (not sure what model year you have) comes with 225/45/18 (F) and 245/45/18 (R), which means your rear OD is going to be larger than the front and thus the VDC is programmed to regonize this differential.

By switching from 235/35 to 245/35, you're front is now bigger than the rear and it keeps triggering the VDC system since it thinks your wheels are spinning out of control. From what I understand, there is no fix, other than to go back to 235/35 or change your rear to a different size. Or I suppose you could just turn off VDC altogether... not a good idea though if you ask me!

I've read about lots of people who run your exact same setup and have no issues though.... so I'm a bit confused myself as to why that happens. It would make sense if it happened to everyone the same way, but I guess depending on the make/model of the tires, the ODs are somewhat different.

Hope that helps.

davidv

iTrader: (2)

The front tires are taller than the rear.

React3

Thanks for the results but it's strange because the 235/35 wouldn't give me problems.. I just simply put a wider tire..

Wired 24/7

iTrader: (2)

The 235/35 isn't just narrower, it's also shorter.

The sidewall is 35% of 235 versus 35% of 245.

There are some people who say that 275/30/19 is "ok" but this thread pretty much proves it's an incorrect size.

DavesZ#3

iTrader: (26)

Sure, you put on a wider tire, but remember that "35" represents the height of the tire as a percent of the width. So when you went from a 235 to a 245, the sidewall height went from 82.25 (235*.35) to 85.75 (245*.35) and that increased your overall tire height. Based on the tire calculator, the front tire increased 0.3" in height. Apparently enough to throw off VDC. You really need the 275/35/19 in the rear or maybe a 245/30/19 in the front will fix it.

Wired 24/7

iTrader: (2)

^^ Slow poke hehe

3-fity

iTrader: (4)

Does VDC have this issue it the fronts are shorter than the rears?

I just went from a 225/245 setup to a 225/255 setup, all 40 series. I need to replace the front tires, but they don't make a GS-D3 in 235/40. That means I would have to get 255/35's on the front and I am pretty sure that they wouldn't fit on the 8" wheels. Plus I would like to have some sort of stagger. Any suggestions?

DavesZ#3

iTrader: (26)

The fronts are supposed to be shorter than the rear. I've heard it said that the rears should be between 0.5 and 0.75" taller than the fronts. In reality, I've seen tire combinations that fall outside that range work fine.

The diameter of the stock 225 tires is about 25.9", the 245 rears are about 26.7". So you want to pick tire combinations that are close to those sizes so you maintain the proper front/rear stagger as well as keep the speedometer/odometer readings accurate.

3-fity

iTrader: (4)

Thanks! I guess I'll go with 245/35's. Does a 245/35 F 255/40 R sound like a decent stagger?

Sorry for hijacking the thread. I just thought it seemed relavent.

davidv

iTrader: (2)

That is very difficult to tell if it is VDC or TCS because they are working in tandem.

I suspect that it is TCS. Consider my Enthusiast with TCS only. I previously had a tire mismatch that not only would SLIP, but it also put the car in the limp mode. Pretty serious stuff for having the wrong tires on the wrong axles.

davidv

iTrader: (2)

Please use this calculator: http://www.dakota-truck.net/TIRECALC/tirecalc.html

3-fity

iTrader: (4)

I have used that. It doesn't really help any. It tells me I would have to put a 255/35 on a 8" wheel in order to stay with appropriate sizing. So my problem is that I need to find a GS-D3 that is CLOSE to the right size for the fronts that won't screw with the VDC.

It seems a 245/35 might be the closest I can come. It is a bit shorter than the OEM front tires. But not by too much, and I think I can fit it on a 8" wheel comfortably.

3-fity

iTrader: (4)

Ok, last question.

Is there an issue with squeezing a 255/35 tire on an 8" wheel? Any body out there done that?

barthelb

Its fine on a 8.5, don't know about an 8. Just try to keep the front diameter an inch shorter than the rear. Right now im running a 245/35/19 front and a 285/35/19 rear and it is fine. Just try to keep it about 1" overall diameter difference, with the front being shorter.

3-fity

iTrader: (4)

Thanks! This is what I was looking for.

Do you think a 1.2" difference between the fronts and rears will cause any issues?

davidv

iTrader: (2)

What is the difference in height between the OEM front and rear times?

barthelb

Since a 245/35 RE050A is 25.7" overall diameter and a 285/35 Michelin PS2 is 26.9" overall than no 1.2" difference will not cause an issue as long as the front is the shorter one, as this is the size and brand i was running.

barthelb

On the touring model it was 1" Front 25.8 Rev 804 Rear 26.8 Rev 775

3-fity

iTrader: (4)

barthelb, you're the man. Thanks!