In general, larger wheels are heavier, and additional weight hinders performance.
You have several things to consider if you are going from 15″ to 17″ rims but you also have to take rim width and tire aspect ratio into account. Also the rim “offset” is very important, it determines how far the tire sticks out or moves inward towards the car. A bad offset can make ruin the handling characteristics of the car. Also you have to make sure that the wheel well clearance is correct so the tires do not rub on the fenders when you turn or hit a bump. The best way to get a rough compromise is to go to a lower aspect ratio. For instance, going down one size is roughly equal to 1″ of rim size. If your original wheel is say a 195/60/15 you could probable go to a 205/45/17 and have a good fit (you will still need to do your homework to make sure). One important thing to check on is what sizes were offered as options on the car you have. 15″ would usually be used on base models with 16″ or 17″ offered as options on the higher end models. If there is a 17″ option you can use that rim and tire size and be good to go. Many tire store web sites will provide a list of rim and tire options that are safe to use on your make and model of car. As rim size increases it leads to increase in weight, which has adverse effect on fuel economy. So its better to use rim which is originally given by the manufacturer . They doesn't simply select the rim size, they do it after various calculations and analysis. So use it as it is given. If u feel that the design is not good then look for the alloy wheels of different design with similar size.