there is a set of used Work Emotion XD9 17x7.5 wheels +42mm offset for sale that I am looking at.

it seems that 17" doesn't seem to be a very recommended choice for my car (1999 Civic SiR) What are the reasons for this? What problems may I run into if I buy these? (the price is very tempting)

 

You can get them. You can use 205/40-17 tires on 17" wheels on your car. (I can't vouch for that offset being good or not.)

There are a few downsides with using larger wheels.

One is tire sizing, but this doesn't affect your car. Some cars (such as CRXs, del sols, and pre-'97 Civics) use smaller tires and the 205/40-17 size (which is the smallest commonly available 17" size) is a bit too big for those cars and can rub and/or can slow the acceleration. However, 205/40-17 has almost exactly the same outer diameter as your stock size, so it should be fine.

Another is that, when you use the proper tire size, the larger the wheel is, the shorter the tire sidewall is. A short sidewall can make the tires more responsive when cornering, but can also reduce the ride comfort by creating a firmer, harsher ride.

I wouldn't use 17" wheels on older cars that need smaller tires, but for your '99, if you like the look and don't mind the slightly firmer ride, go for it.

 

the 7.5 width of the rims shouldn't be a problem should it?

 

that wheel will fit fine on an EM1. I personally think 17s look better on them.

as for the width and offset they should be fine as long as you aren't dumped 4".

 

17=buku

 

You probably would want +42 offset for a slightly wider wheel anyway (7.5 instead of 7) and just don't dump it. I don't know why you would, the car handles worse when its on its nuts anyway!

 

You probably would want +42 offset for a slightly wider wheel anyway (7.5 instead of 7) and just don't dump it. I don't know why you would, the car handles worse when its on its nuts anyway! If you do dump it, you probably won't be able to get a camber kit if you wanted to because the tires would hit the fender (it happened on my ej1, I don't know if it would apply to your car too)