[Keenercarguy]

So you're right but there's more to it than that, 225/45 weight about a pound less than 245/40's, just one pound, but that's not even the big difference between them. The 225/45's have a higher sidewall by about 1.6% over the 245's which are also already .8% taller than stock. You risk losing some noticeable acceleration on them, granted I run 225/45 pilot super sports on my daily's and I like them. But the weight difference can be easily offset by the gearing change, your speedo reads more than twice more wrong with the 225/45's verse the 245/40's which have more grip. Both are decent sizes especially for sidewall ratio to width but this is a comparison
(225/45/17 PSS weigh 22lbs, 245/40/17 PSS weigh 23lbs but are basically an inch wider, under 5% increase in weight for a 10%+ increase in traction, and better gearing, is a worthwhile trade for a lot of people) number source: tirerack