First off.. Welcome to the forums!
Hi,
I was interested in changing wheels on my 2008 mazda3s hatch from 17 to 16 to decrease poor road surface rattle to my spine as well as reduce poss of wheel breakage and tires[bubbles] by having the xtra inch of rubber[ I live in city with some poor roads]. Do you think the effect of aprox an xtra inch of rubber[205/50/17 to 205/55/16] on comfort will be significant and do you think this will reduce handling minimally. Thanks.
Technically, it'll only be an extra 1/2" of rubber between the wheel rim and the road. There's a 1" difference is in the diameter, but only half of that is relevant since opposite sides of the tire are not in contact with the road at the same time (nor could they be). So, dividing the 17" and 16" diameters in half, you get 8.5" and 8.0" radii respectively, a difference of 0.5".
While that could theoretically make a difference in terms of reducing tire and/or wheel damage, my own personal experience is that it doesn't affect the ride or handling that much. Sure, bumps are a little less pronounced, but only a little, and that's when switching between my stock 17" "Snowflakes" with the 3-season "high-performance" tires with a 93V load rating (stock is 88V) and the 16" steelies with the winter tires and a 91H load rating. There's a more noticeable effect on handling, and that could be from either the extra 1/2" of distance to the road or it could be from the tires themselves (the winter set doesn't do as well as the 3-season set in handling, braking or acceleration on dry pavement >40F; they're better than the 3-seasons on wet and/or snowy and/or icy surfaces <40F), but it's still fairly insignificant overall.
One thing to make sure of is, since you have TPMS, that you get wheels that can hold TPMS sensors. I didn't with my winter steelies, but that's a chance I'm willing to take for 3 months out of 12. Being that you'll be running on wheels other than the factory set for an extended period, it'd be a good idea to get them with sensors or at least with the ability to install them. (You can get wheels either with or without sensors, but if you get them without, you'll need to take the ones that are in the factory "Snowflakes" out and put them in the new wheels.)
Other concerns revolve around tire/wheel sizing, but there are other posts about that. Just hit the "Search" in the forum's tool bar -- it is your friend. (2thumbs)