997.1 4S all season tire setup question.
10-13-2018, 01:19 PM
#1
997.1 4S all season tire setup question.
I posted this in the 997 forum, but probably best addressed here. Just picked up an 08 C4S coupe and plan to DD year round in Ohio. I need a winter wheel and tire set for light snow and ice. I will not be driving in heavy snow or ice and prefer more options than dedicated snow tires, so I am trying to source an all season tire combo with 18 or 19 inch wheels. 19 inch all seasons are hard to find, like Toyo Proxes 4, so will probably go 18 inch like Conti DWS06 which make 295/35/18 which I know will work ok per Tire Rack and Porsche manual, with 235/40/18 fronts.
My real preference is to try 285/35/18 because there are multiple brand options like Michelin AS3's. This will be a shorter than stock tire height and throw off the rear to front height difference. Will that matter much with handling and especially with the AWD system and other car systems including ABS? Might I get an error message or other problem? The car has full Bilstien adjustable system, I think the damptronic version which I am trying to confirm. I am going to raise the suspension about 10mm and get an allignment after getting new wheels and tires for winter if that matters.
Other question is if I get wheels that I know work for the widebody, per Tire Rack anyway, specifically 18x8 and 18x10, can I safely run the NB snow tire sizes of 235/40 fronts and 265/40/18 rears. I'd still use all-seasons instead of snow tires. The 265/40's are basically same height as stock 305/30's and front to back height difference is basically stock too, and the 265's fit the 10 inch rears.
This winter setup is only for commuting with no aggressive driving, therefore reduced traction compared with true winter tires is not of concern, but I do want the car electronic systems to be "happy." I drove last winter on summer tires on an Audi with AWD and the year before that on RWD car with summers. Not fun but I am very carefull in winter, so absolute traction is not highest priority. Basically, I am not buying the Pirelli snow tires.
Thanks much in advance. I've read many threads but have not gotten exact answers to my situtation
My real preference is to try 285/35/18 because there are multiple brand options like Michelin AS3's. This will be a shorter than stock tire height and throw off the rear to front height difference. Will that matter much with handling and especially with the AWD system and other car systems including ABS? Might I get an error message or other problem? The car has full Bilstien adjustable system, I think the damptronic version which I am trying to confirm. I am going to raise the suspension about 10mm and get an allignment after getting new wheels and tires for winter if that matters.
Other question is if I get wheels that I know work for the widebody, per Tire Rack anyway, specifically 18x8 and 18x10, can I safely run the NB snow tire sizes of 235/40 fronts and 265/40/18 rears. I'd still use all-seasons instead of snow tires. The 265/40's are basically same height as stock 305/30's and front to back height difference is basically stock too, and the 265's fit the 10 inch rears.
This winter setup is only for commuting with no aggressive driving, therefore reduced traction compared with true winter tires is not of concern, but I do want the car electronic systems to be "happy." I drove last winter on summer tires on an Audi with AWD and the year before that on RWD car with summers. Not fun but I am very carefull in winter, so absolute traction is not highest priority. Basically, I am not buying the Pirelli snow tires.
Thanks much in advance. I've read many threads but have not gotten exact answers to my situtation
10-23-2018, 12:28 PM
#2
Three Wheelin'
Join Date: Jun 2016
Location: Toronto, north of the lake.
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I just put 235/40R18 and 265/35R18s on my 996 C4S. I went with the PZero AS Plus based on the Tire Rack tests. I have given up on trying tire sizes that aren't approved by Porsche*. The AWD system on the 996 and 997.1 cars work the same (but have different final drive ratios) and depend on the "right" size tires to work properly. In low traction conditions, I have decided I want the AWD system working at its best.
So that leaves you with the DWS06 as it is the only tire made in the correct size.
* In this case the difference in diameter of the 235/40R18 PZero AS Plus vs the rear tire is the same as the difference for the Dunlop SP Winter Sport 3, the Porsche recommended tire.
So that leaves you with the DWS06 as it is the only tire made in the correct size.
* In this case the difference in diameter of the 235/40R18 PZero AS Plus vs the rear tire is the same as the difference for the Dunlop SP Winter Sport 3, the Porsche recommended tire.
10-23-2018, 04:18 PM
#3
Former Vendor
996 and 997 sizing is different. The OD of the back tire on a 997 should be .75" taller for the AWD to be happy.
265/40 is about .9" taller than 235/40, and should be OK as long as the offset on the back wheel is not too low.
Call me if I can help!
265/40 is about .9" taller than 235/40, and should be OK as long as the offset on the back wheel is not too low.
Call me if I can help!