[Canada Kev]

It's kinda not deep freeze weather up here any longer and spring is promising to show up before too long. I spent some time putzing about in the garage today where it was surprisingly warm.

I found a flat tire with the offending nail proudly showing itself imbedded in the rubber on the front of my car. It's likely been flat at near freezing temperatures for the entire winter so the tire is probably ruined. But that's ok as they are in need of replacement anyway.

I'm running (and happy with the performance of) Continental ExtremeContact DW tires in 225/45 and 255/40-17 but they don't make the DW in those sizes any longer. My rears still have a season of life left in them as they were new a year and a half ago, but the fronts are almost twice as old.

My question is what is the consensus here on these two options:

1. replace the fronts with the Conti ExtremeContact Sport, which I understand are the replacement for, and quite similar to, the DW, and leaving the rear DW until next year

OR

2. replace all four now.

I get that these cars can be sensitive to tire selection and that having mismatched tires front to rear isn't a good thing. On the other hand, I gather that the Conti Sports are very similar to the DW in most of its characteristics. Would this mismatch upset the handling and be a big fat no-no?

Buying two new rear tires isn't the end of the world, but it seems such a shame as there is quite a bit of tread remaining.

Most of my driving is in the city or highway to get to the bendy mountain roads for some more spirited hot rodding.

Your opinions are appreciated.