235/40/18 winter tires on oem wheels VS replacing rear OEM wheels with 18x8
 

Is there any safety or driveability issue with putting winter tires on OEM wheels without changing the rear 2 wheels to match the size of the front wheels?

I have settled on the Dunlop Wintersports 4D after much reading but I like the looks of the OEM wheels and don't want to replace the 2 rear wheels with 18x8 unless it is recommended.

Will I do any damage to my car by using 235/40/18 all around on the OEM wheels?
Is it bad for my car?
Is it unsafe?

Will I be able to tell the difference btwn this setup and replacing the rear 2 oem wheels with 18x8s, i.e. braking, turning, ride comfort???

I plan on getting 19 inch HREs for the spring with PSS...

Thanks.

Can anybody weigh in?

Would this affect ride comfort?

I'm not 100% sure it will fit in the rear, 40 aspect ratio will increase the size of the tire significantly.

It will definitely have an effect on the odometer and speedometer.

235/40/18 for Rear Winter Tires
 

I ran the 235/40/18 on the stock rims at all four corners for 3 winters (2 sets of tires) using Michelin Pilot Alpin PA2 and PA3 tires with no issues.

Dunlop provides an acceptable rim width for the Winter Sport 3D tires of 8"-9.5". I am unable to locate the 4D specs as they are too new, but would guess the specs will be similar to the 3D, but you should verify before you order them.

As the rear tires are the same height as the fronts and 0.4" (25.4") taller than stock (25"), there may be a 1 mph difference in the speedometer.

For comparision, if you run 265/30 or 275/30 on your summer 19" rims with Michelin PSS tires, they will be 0.3" (25.3") and 0.6" (25.6") taller than stock respectively.

To answer your questions specifically,
No.
No.
No.

Having not run the 235s on a 8" rim, I can only guess that there may be more sidewall flex than on the OEM if you chose to get 18x8 for the rear.

I hope that this helps.

I just bought Winter tires in 235/40/18 to put on my OEM rims. It's not on yet, but I have given it a lot of thought. The rear will be stretched but is not unsafe or cause any damage.

The point of winter tires in winter is to have traction and to stop when needed. Just because you have winter tires, it doesn't mean you can drive like you are on summer tires in the summer. In my opinion, don't worry about performance in the winter months. Concentrate on getting your car in one piece for when spring comes, the fun starts again.

This info is amazing!
Thank you very much for taking the time to explain so thoroughly.
I feel a lot more comfortable about putting winter tires on the stock rims now.

One more question for you, if I may:

My choice came down to pilot alpin pa3/4 and dunlop wintersports 3D/4D -- so why did you choose the alpins and how are they in the snow?
I live in chicago...

you have an evo so you can have fun in the winter :zoom:

I took delivery of my 2009 in November 2008 and at that time, the only winter tire I could get was the Alpine PA2 (Blizzaks were already unavailable for the year and the Dunlops were not available yet). When the PA2s were worn out, I replaced them with PA3s and had similar experience.

As I live in the PA area, I probably have less snow than you do in Chicago and if there is more than 2-3" of snow on the ground, I am typically in a position that I don't have to drive. I have driven in 2-3" inches of snow on a couple of occasions with ice/slush and did not have issues. However, I have read that the Dunlops are better in deeper snow and/or ice.

Thrilla makes a very good point - winter tires are to get around in the winter months safely and not really for performance. You will need to understand the dynamics of the car as well as the conditions you are driving in as no matter how good the tires, in poor conditions, it is easy to overdrive the tires.

One other note, the Alpines are more "blocky" then summer tires of the same size and don't really look stretched on the rear rims.

Finally, be mindful of the Winter tire temperature range. The Alpines start to wear very quickly when the temperature of the road reaches the high 50s.

I hope this helps with your decision.

Thanks again for your response.

Since the dunlop D4 is not available in north america in the right size until next winter and the alpin pa4 doesn't have enough reviews, I am left with no choice but to go with the dunlop D3.