I recently installed winter tires on 2004 z roadster and as the dealer didn't have the exact same size tires and were on the car he said it would be not problem to install 225's all the way around instead of putting 245's on the rear....Since then even on dry roads the slip light will come on intermittently which is a bit of a pain since you can't accelerate while the light is on. Would anyone be aware of whether the tire size can affect this.
thanks
Premium

 

Absolutely- The rear tires are too small,they rotate quicker than the stock 245's and thus the slip control thinks they are slipping.

Suggest you make dealer replace with the proper size!!

 

Do you have VDC?

 

i have an 03 touring MT (w/ OE 18s). I just put on snowtires on my 17 inch wheels (off of an enthusiast model) and have equipped them on my touring. i got tirerack's recommendation size of 225/50/17F and 225/55/17R. yes, correct. no stagger and taller sidewall on the rear.

i just put em on 2 days ago and have driven 70miles so far. i havent had any issues with the VDC, as promised by tirerack. i made sure that there would be no issues prior to purchasing this particular setup.

i havent really driven hard either though. but then again, why should i? snowtires + dry pavement = a joke. i dont like the feel at all. i feel like i am driving a minivan.

i'd say just turn off the VDC and drive on. you will probably have more control with it off in snow anyway.

 

DavidV- I have a TCS off button which I assume is traction control and am not sure if that is the same as VDC. As far as the tires go although I am no expect in this field I have thought that the three digit number ..ie 245 referred to the width of the tire and the two digit number referred to a height/width ratio. I have to agree with TekwonV that driving this machine with snows is very similar to driving a mini van. It does however beat fishtailing all over the place. Perhaps the best answer is to turn off the TCS but that does seem to defeat the purpose of having it.....

 

Hmmm...just noticed in searching the Nissan site that VDC is not the same as Traction control...and am not sure how to tell if I have VDC-Is there a VDC off button that would indicate this? If so I don't have one.

 

DO NOT turn off your TCS!!! That would completely negate the whole idea of having snow tires. A Z without the TCS in snow would be completely useless even with snow tires. The best snow tires will definately increase traction but in any amount of significant snow fall or covered roads you will still kick in the TCS, especially when starting from a stopped position like a red light.

your problem is most definately from the rear tires being too small, or rather short. Our cars need a .5 inch heigth difference with the rears being taller by the .5 inch. to be sure, follow the link in the wheels section to find the tire calculator and plug in your sizes. if the end result is smaller than .5 inch difference, or even worse equal in heigth or shorter, then you know you have found the culprit and you need to get different rear tires.

do yourself a favor and do this now cause as we get further into the winter the proper sizes start to become scarce!!!

 

here ya go!!! I was in a helping mood. follow the link, and plug in the numbers of your snow set.

http://www.discounttiredirect.com/di...foTireMath.jsp

 

Thanks grifferjr for the information! My Nissan dealer appears to be useless as they are the ones that sold me the winter tires. I would be better off asking questions on this forum then to the moron at the dealership......Thanks again.

 

I would drive around with TCS off, unless there is rain or snow on the road in which case you probably don't want to accelerate fast anyway. Thats what I do.

Grifferjr, what part of Dayton do you live in?

P.S. The Z sucks in the snow!

 

I’m going to disagree with fellow forum members about TCS. Unlike VDC, TCS is NOT sensitive to tire-wheel size. TCS will allow a particular rear wheel rpm difference, then activate SLIP.

I believe that the problem is cold road surface. I took a ride last evening. The road surface was about 36 degrees. During spirited acceleration, I got SLIP in second, third and fourth gears. It didn’t matter if the tires are warm, cold asphalt is terrible for traction.

 

I assume you drive the Roaster Enthusiast. You have Traction Control System (TCS) NOT Vehicle Dynamic Control (VDC).

 

Thanks davidV...I will have to rethink the purchase of two new tires...

 

Just as a followup DavidV I was not accelerating at the time slip came on...I was moving rather quickly but just maintaining speed.....do you still think it is simply a slick surface...the slip stayed on for 15 seconds.

 

disagreement duly noted. from the explanation that i received back in the day. TCS works by sensing if the rear wheels are rotating at a speed quicker than they should be in relation to what the front wheels are rotating. thus if the car senses that the rears are rotating too quickly then the TCS is activated to remove power from the rears. this is handled by the cars computer and is programmed with the .5 inch ratio in mind. if you get a set of rears that are less than the .5 inch or the same heigth or even worse smaller (which is a common error with some aftermarket mods) the car thinks the rears are in an essence spinning when they are not. doest happen all the time but primarily with high level driving and cornering or in this case should the car be challenged with adverse traction conditions.

it is an error but actually an error on the safe side cause you will be activating the traction control easier which in some opinions could be better in situations like heavy snow. you just wont have any power under the rear wheels.

 

Thanks to grifferjr and davidv for the thoughts..i think I will live with the slip for now since i am faced with four new tires in the spring...got around 25000km from the potenzas and won't be putting them back on the car....I am thinking that the goodrich
g-forces T/a will be fine.

 

premium, sorry i didn't see this thread as well, i answered in your other post asking the same question

davidv, i'm no expert, but i have to disagree that TCS is wheel/tire size sensitive

repost
from the factory service manual
page BRC-48 and 96
"TCS function: the wheel spin occurance is detected by....wheel speed signals from all 4 wheels...."

page BRC-96
"VDC function: driver steering amount and brake amount are detected....and the vehicles driving status....is determined by yaw rate sensor/side G sensor, and wheel sensor"

both edited for brevity
TCS uses wheel speed sensors. it is expecting your front/rear wheels to be traveling at different speeds given the factory rolling circumference stagger. so by neccessity, it will be wheel/tire size sensitive. VDC also uses wheel sensors but uses several other inputs as well.

tekwon is correct: you could have run 225 front rear, but needed a taller sidewall for the rear to have the rolling circumference stagger. for example 225/50/18 is 26.9" while stock is 245/45/18 is 26.7"

also agree with others that losing your TCS is defeating the benefit of going to snow tires.

pp

 

Hmmm, let's see...my Z with V-rated Alpin2s feels great on the dry pavement (even with 225s all round) and had amazing snow traction last year. It was better than my wife's Golf with all-season tires. I had no issues last year with a 100 mile round trip everyday all winter--I didn't miss a trip.

VDC and TCS aren't essential to drive in the snow, but I can imagine they help tremendously.

 

Edogg218 do you turn off the TCS in the winter?

 

I have but a lowly base Z