03 S40 after market wheels
 

My 03 Volvo has a stock wheel that is 15'' x 6.5'' (or 6'' I'm not 100% sure) with a p195/60r15 tire. The after market wheels are 17'' x 7.5'' with a 225/45/r17 tire size. If I put a 225/40/r17 tire on the after market wheels will is damage my suspension or abs in a negative way? What would this change affect? Is it worth it?

There won't be any issues assuming the wheels are the correct bolt pattern, offset and center bore. Check wheel-size.com for the recommended rim specs.

The only difference between the 225/45r17 and 225/40r17 tire is the rolling circumference of the /45 is a bit longer (ie tire is taller) by 1 or 2% so your speedo may change by 1 MPH. Are you sure about the 225/40r17 size - that's not very common where the 225/45417s are...

I used a tire comparison website and I changed the middle number until I found one that was closest to the size of my original tire. I'm assuming it should still fit the rims.

tires should fit fine. My final comment was just to note that not all tire sizes are common and can be hard to source replacements in that exact size. you will find plenty of brands and styles in the 225/45r17 or a 215/45r17 size that will be a close match to the +2 size for the 195/60-15s. the 225/40r17 will work fine as well, but there's not many tire styles in that size.