O.k., than the decision you face is the same as one I just recently made.
Having purchased a Mazda6 last April, I endured the OEM all-seasons through the summer and early autumn. I was pleasantly surpruised at how adequate the MXM4s were on dry roads. They were not the best tires I've driven on, but they were much better than I expected them to be.
Come the autumn rains of the Pacific Northwest, though, and they were downright scary. So I had to put to use the research specific to the Mazda6 on 17" wheels that I've been conducting over the past six months.
The tire model that has been winning virtully all of the recent comparative tests is the Goodyear GS-D3. In a recent test in Car and Driver magazine (current issue on the stands, page 124), there is a remarkable statistic. In emergency stops from 60 mph at the Goodyear Tire test track in Akron conducted, not by Goodyear, but by Car and Driver, the stopping distances were identical (132 feet) on dry pavement and on wet pavement. I've never before seen a test (including Car and Driver's own 11-tire test at the Tire Rack test facility published in the December 2005 issue) where the wet stopping distance was as short as the dry stopping distance. I bought a pair of the GS-D3s for the front positions on my Mazda6. Because the GS-D3 does not come in a 215/50-17 size, I purchased 225/50-17s. They fit well, without rubbing the front suspension arm.
I was not certain that a 225/50 GS-D3 would fit without rubbing in the rear wheelwell without fender rolling (which I've not done). Moreover, the GS-D3 is a directional tire, and a directional tread design buys you essentially nothing in rear mounting, because the rear tires follow in the track already cleared by the front tires, so there is no standing water to evacuate -- the only function of a directional tread design. So I decided to partake of the advantages of asymemtrical tires in the rear.
A configuration of asymmetrics rear, directionals front is, by the way, a well-tested strategy. Pirelli came up with the concept, and in several of the Pirelli lines, the tires are made in both asymmetrical and directional designs, with the advice to mount the directionals only at the front. Pirelli recommends only two configurations in those tire lines: asymemtricals at all four positions or directionals front, asymmetricals rear, but never directionals at all four corners.
At the rear, I mounted Yokohama Advan Sport asymmetrical tires. That is a terrific tire. Again, Yokohama does not make it in a 215/50-17 size, so I mounted 205/55-17 tires. The measuring rim for the 205/55 is 6.5", and, mounted on a wider, 7", OEM Mazda6 rim, the actual section width is closer to 210 mm. The contact patch of the 205/55 is the same size as the contact patch of the 215/50 it replaces, but is a smidgen longer front-to-back, and a smidgen narrower side-to-side than the 215/50, just a smidgen.
The overall diameter of the mounted 225/50 Goodyear GS-D3s at the front and the mounted Yokohama Advan Sports at the rear is identical; both are about one precent larger than the OEM 215/50 Michelin MXM4s, which will result in slight speedometer and odometer error.
The OEM Michelins have a load rating of 93, but the SL load ratings are for 35 pounds pressure, and the recommended pressure for the OEM tires is 32 pounds. Derated to 32 pounds, the load capacity of 93 load-rated Michelins is the same as the load rating of the 91 load-rated 205/55 Yokohama Advan Sports at 35 pounds. In fact, I have inflated the 205/55 Yokohama Advan Sports to 35 pounds, so I have the same load rating as the OEM Michelins at Mazda's recommended 32 pounds. The Goodyear GS-D3 225/50-17 load rating is 94; I have inflated those, also, to 35 pounds, giving me an extra load margin under the V6 engine's end of the vehicle. I am using two high quality air pressure gauges as a cross-check against each other, and all four tires are within one-half pound of pressure.
So how did this work out for me, you well may ask. Initially, it appears that my homework was vindicated; the combo seems to work very well. But it is early yet to give a definitive answer; I've not yet had a chance to give the tires a workout. I'll let you know later how well it works for me.
I also heard that the Fuzion HR-i sucked. But I'm on my third vehicle with the Fuzion ZR-i and they rock.
And when you compare them to to other Z/W rated tires and include price in the evaluation, there is no comparison. I knew the OEM Michelin's were horrible every time I went around a corner or got a heavy Florida rain on the highway, but after just a few miles on these tires, I remember why I put them on my Protege5 and my wife's SLK.
I got four 225 45ZR17's shipped from Tire Rack for just under $400. They fit beautiful and I'd recommend them without hesitation as long as you aren't in freezing weather and/or snow. (They are supposedly horrid in the snow, but not a big concern in Orlando!)