I know many of you will find this weird, but bear with me. If you don't like me driving my 718 in winter, then don't reply.

I have "been there done that" multiple times with 'performance winter' tires. Long story short, they just don't have near the ice traction as real winter tires, not even close. I live in central Canada, and I don't just drive in the odd snow storm, but we drive in legit ice and small amounts of snow for 4-5 months a year.

For me this car is a 360 day/yr car (not 365, as I know a few days every year we will get a decent dump of snow, so we will get by on one car for those brief periods).

To the questions:

Car comes with 235/35/20F and 265/35/20R tires

Overall diameter is 26.5"F & 27.3"R

I can't find any good winter tires in the 18 or 19" sizes. Correct size would be 235/40/19F (dia 26.4) 265/40/19R (dia 27.4) or 235/45/18F (dia 26.5) 265/45/18R (dia 27.6).

Soooo, this are my thoughts:

I like the Nokian R2s, they are a great tire in ice (and ice is mostly what I drive on), but they don't have those sizes, so I was thinking:

• 235/45/18F which are the right size
• 255/45/18R which are close, but then dia goes down to 27, so I end up losing about 1/4" of rear ground clearance

• 225/45/19F which are close but then dia goes up to 27" (will that increase of radius of about 1/4" affect anything?)
• 245/45/19R which are not that close, dia goes up to 27.7"
  • OR
• 255/45/19R which makes dia go up to 28.1" so again an increase in radius of about 1/4"

I kinda would like the increased ground clearance (1/4" isn't much, but it is 6MM, so almost makes up for the SPASM 20mm drop vs PASM 10mm drop).


And here is the final wrench thrown in:


I also want to get another two wheels with the identical rear tire, just this time studded. I would only use it for a few days a year when it is bad out, but I feel it is worth it. And yes I know all about mis-matching tires on a car, I would never throw better traction front tires on a FWD car (oversteer city), but this is just like in the gold old days of putting studs on the rear of a RWD car, works well, ovbiously more understeer, but still more traction, and safe traction. I can swap rear wheel in about 5 mins, so once things clear up it would be back to identical tires all around.




Thanks for your guys help!

 

No replies

 

235/45 18 and 265/45 18 are the right sizes to keep overall diameters correct for the car. Don't worry as much about ground clearance as proper drive train OD's, A few MM's in clearance isn't going to make that much difference.

Pirelli and Dunlop both have offerings in that size combination.


Michelin has the Pilot Alpin PA4 in 265/40 19 and 235/40 19. That is the correct 19" sizing to use.

None of these performance winter tires are pinned for studs, and you won't want to run studs anyway - especially just the back. That's an invitation to an terrible handling car.

Please call me if I can help.

 

I would stick with stock sizes and N-spec tires as they are really the only winter tires available. PA4's should be the better tire out of the bunch but the 18" 235/265 45 profile Pirelli's and Dunloop winters should also be good. I bought a new/used wheelset with PA4's in the spring so unfortunately I haven't been able to test them yet.

 

I actually spoke with the Tire a Rack about this. Officially they don’t recommend what I suggested in the OP. But they do readily admit that the PA4 and other high po winters don’t really have near the ice performance that other winters have.

He gave me some other suggestions, which of course end up with a slightly larger tire size. But the difference is only about 2%.