Hi... On my 06 G35 6MT I recently bought two new tires for the back (Kumho Ecstas) in the original size, 245-40-19... The fronts are still the original Bridgestone Potenza's... They still have considerable miles left on them and that, coupled with my desire to see if I like the Kumhos (granted a bit hard to tell with the Bridgestones still on the front), is what prompted me to only get two tires right now...

Coming off a freeway exit that I take every work day, never before had the VDC come to life (at least I think that's what is happening)... But the two days since I've had the Kumhos and taken this same exit at the same speed I always do, as I come around the curved part of the exit ramp, certainly not squealing any tires but going at a good clip, I feel what I assume is the anti-lock brakes kicking on even though on the second time it happened I wasn't even touching the brake pedal...

Am I correct that this is the VDC doing this??? And if so, why?? Is it sensing slip even though I don't??? I know I can switch off the VDC and I will likely try that soon as an experiment but I think I would rather leave it on if possible... Does this often happen with new and different (from OEM) tires??? Is the fact that I have only two new tires perhaps part of what's going on??? Any feedback would be much appreciated as I am new to VDC...

thanks much... bob..

 

its due to the difference in grip of the front and rear tires, sometimes it happens, sometimes it doesn't. Its easy to verify by repeating with the VDC off.

 

If I remember right, the Kumhos didn't grip as well as the oem RE050s in a 2005 tire test. Listed at Tire Rack's site. IMHO, that might explain why the RE050s gripped fine and the new Kumhos cause the VDC light to come on. (at the same freeway exit ramp)

 

this is a common problem when you mix 2 different brands / tread patterns on the car....you should replace your fronts with Kuhmos so you are running a matched tire set.

 

Thanks for the feedback... I appreciate the help... I thought it likely was what you guys said, mixing tires... The Kumhos do have a radically different tread design than do the Bridgestones and I'm sure the grip is different too... I'm likely gonna go ahead and put Kumhos on the front as well shortly and just give up the remaining tread on the Bridgestones... Plus, the only way to really know if I like the Kumhos is to run them on all four wheels... Again, thanks for the feedback... bob...

 

VDC off!!! In nice weather I think VDC is actually more dangerous than it is helpful, especially when entering/exiting freeways.

 

Ya it was like what other said before about mixing tires.

 

While I agree with most of you that it is because of mixing tires; I think it also shows the lower grip of the Kumhos. So if you were to also switch the front ones you'd be loosing traction there as well. Maybe you'd be better off trying to get rid of the Kumhos through some doughnuts and get back to Potenza's. I don't where you drive and in what conditions but I am a huge fan of Bridgestone tires, especially the 960s. Even though their sidewalls are not that stiff they have exceptional grip especially on wet.

 

IMHO, it's not the mixing of tires. If he ran Kumhos on all 4 corners, the VDC still would have kicked in.

 

had the same problem, refer to this thread: https://g35driver.com/forums/brakes-...acting-up.html

one easy solution, i learned it doesn't kick in if u accelerate through the whole turn =)

 

turn it off

 

I recently put new tires on the back so now I'm running a mixed set. Nitto on the back and toyo on the front. Same thing happened to me while exiting last weekend and the "slip" light came on and VDC kicked in. Freaked me out at first wasn't sure what happen right away!

 

Hmmm...i have a 03 5AT non brembo so i dont think i have a VDC..
but i have similar problem with braking moderately in downhill mountain driving....except that i am running 4 same tires but the rears, instead of 275/35/19 i have 275/30/19 coz the mfr do not have that size...=.=
what i felt must have been ABS...but i wasnt even going downhill that fast. It's making it more dangerous...do u guys think it's the 30 series rears that is making the ABS engage?

 

i have the same problem >< potenzas in the front, t1r's in the rear

 

I don't think it has to do with mixing of tires. I have Toyos T1R on my car and I just replaced the rears with the same. Ever since the rears were replaced, I've been having this problem even though there are still plenty of tread left on the fronts.