Howdy, will be taking delivery of a new '06 Impreza 2.5i sedan tomorrow and looking to verify some wheel info. It has the 5-bolt alloys w/ P205/55R-16 89V Potenza's RE92A rubber... which, IMHO, were less than impressive in the snow during my test drives. Thinking about swapping on a set of almost new 215/60R-16 snows I have sitting around, but I have some questions if you're inclined to help:

 

1.) The car has ABS and EBD, but no VDC (Vehicle Dynamic Control). I undestand that changing tire sizes in a VDC equipped car can cause havok with the system operation, and a 'max 3% rolling diameter difference or you will screw up VDC' rule-of-thumb is good practice. However, since there is no VDC on this car, what is the max diff% before ABS or EBD is effected? Or, as long as all 4 wheels/tires are the same, does it even matter much? Change in circumference would be 78.2" to 82.2", or 5.1% diff., or 60mph speedo vs. 63.1mph actual.

 

2.) Based on info I gathered on-site, recent Impreza models used a 5x100mm bolt pattern and +55 offset f/r. Is this still the case for the '06 model? Unfortunately, my other wheels are 5x114.3x6-1/2" so I'd need new wheels. What's the cross-applicability to other manufacturers bolt and bore wise?

 

3.) Last, with it's oem neg scrub radius geometry, if I change the centerline slightly by using a wider tire with a lower offset wheel and end up with zero or positive scrub, will I notice any meaningful handling deterioration... keeping in mind we're talking winter, not performance, tires here.

 

Thanks, look forward to being a part of the sube community.

06 2.5i wheel is 55mm offset 16" x 5.5"

 

You do not want to stray too far from the OEM offset

 

I am no tire expert, but I've found that those that try to go BIG

often end up with rubbing issues.

 

ABS should not be affected, but your speedo may vary slightly

 

I hope this helps.

Jamie

Thanks, yes, that does help some. I wouldn't have guessed they were only 5.5" wide wheels, they looked wider. I actually thought they were 6". Re: clearance, there appears to be plenty of fenderwell room from outside of the oem wheel/tire to the inside fender lip but I don't know about inside clearance to the suspension components. Ie., if I used my winter tires on a set of 5.5" +55 wheels, the tire track width would increase by a very slight +0.39", the sidewall height would increase +0.64", and overall tire height by +1.28". I suspect there is enough room for that as long as I don't mess with the offset much, However, if anyone can point to front suspension clearances or a tire/wheel/offset guide from those who have stuffed the wheelwells with aftermarket wheels and rubber, I would appreciate. I was also concerned about monkeying with the unusual negative scrub.

not sure if you've seen this or need it but it helps me out a bit when i want to know the different tires i want to run but not stray out of the "3%' rule.

http://ejelta.com/tiresize/index.html

best tire size calculator i've seen on the net.

Thanks, thats a great calculator in that it spits back a whole bunch of best alternatives with a single input!

Yeah, the ABS will be fine. It uses an accelerometer to verify the wheel speed readings.

 

 

The 06 STi has 5x114 bolt pattern, so maybe your 2.5 does too? Hang on to those old wheels.

 

I would avoid straying more than 5mm from the stock offset. If you are like me, you will notice the difference :-)