The ONLY negative effect will be that your speedometer is no longer accurate. The reason is because your new tires (275/40R17) overall height is taller than the original (235/45R17) tires. It's OK to go with wider tires as long you keep them the same overall height. The proper size tire to have the wider, sportier look but still keep your speedo accurate is 255/40R17. In Japan they have an even wider tire that I use to run on my '89 Supra Turbo: 285/35R17. Your choices for 17" tires are: 235/45R17, 255/40R17 and 285/35R17.