Running 205/55R16 instead of 225/50R17 - s'aight?
Posted: Fri Nov 04, 2005 1:28 pm
Ok, here's my deal.My G6 coupe came with the 17" cast-aluminum ChromeTech wheels (running a 225/50/17 tire). The dilemma: OEM tires are crappy-nentals. Same BS tires you find on some Vibes. As most of us know, their wet traction leaves a lot to be desired. Obviously, snow use is not an option.Having SERIOUSLY depleted the fundage on the new car purchase, I am looking for ANY way to get ahold of some decent snow tires for this coming season. My trip to work is 25 miles each way, and I don't want a single one of those miles to be travelled on an unsafe tire. My ideal situation would be a green diamond tires mounted on a set of steel or otherwise non-attractive wheels. Green Diamond doesn't make a tire in 225/50R17. But I already have a set of 205/55R16's from the Vibe that have less then 8000 miles on them. They're practically new.While poking around the Pontiac site one night, I stumbled across something that gave me hope. The G6 4-cylinder and G6 V6 (bottom two models) come with 16x7 steel wheels, wrapped in 215/60R16 tires, standard. They also have available 16" cast aluminum painted wheels as an option. The G6 COUPE only comes with 17" wheels. But there's also now G6 V6 coupe -- only a GT and GTP.My question is this.I contacted Green Diamond, and they assured me the 205/55R16 tires I had last season with the Vibe can be safely mounted and used on a 16x7 wheel (instead of the 16x6.5 they're on now). I asked my service advisor if he felt there would be any issues using the G6 and G6 V6 16" wheel on the coupe. He said not to do it, it would confuse the computers and possibly cause some of the systems not to work properly (i.e. brakes). I checked using that handy-dandy tire size calculator, it says that the car would be running about 3.8% slower with the snows -- i.e. when the speedo says 60 i'd really be doing 58 mph.My question for people who know their stuff is this: Is there REALLY problems that could come from running a 16x7 wheel on the coupe? Because I was of the understanding the sedan/coupe were identical underneath, in which case I can't fathom there being any reason why the sedan could run 16's and the coupe couldn't.Thanks in advance!