Once you know offset, you can calculate what will fit. Measure between the inner sidewall of the tire and the object it comes closest to on the car (shocks or upper control arms, for example). Bearing in mind that half the additional width of the new wheel will go under the fender, if offset remains equal, something will probably hit. To fix this, you'll need to move the wheel out. Either slap on a set of spacers or calculate a reduction in positive offset.
Sizing
Never mind what the car show judges say: smaller wheels are almost always better. They're lighter, allow for better acceleration and handling, and even improve ride quality. Unless the brakes won't fit, 15s usually get the job done for most Honda/Acuras.
Width is different. Wider is better. Wider rims make for a more stable ride, better handling and more responsive steering. Narrow rims don't have much to offer except better ride quality when compared to wider rims. Face it: whether you've got a show queen or a track rat, nobody wants a narrowrim
Clearance
After dealing with the concrete science of bolt patterns and offsets, the trial-and-error process of fitting a wheel inside a fender well is almost refreshing. A lot can change here, including camber as the suspension travels, not to mention the unpredictability of rounded fender lips and the tire's sidewall. This is pretty much a crapshoot.
Fun With Numbers
Most of the time, a set of 15s will give the best acceleration results. But to make sure, you can calculate how any car might be affected when changing wheel and tire sizes. Simply pick an arbitrary MPH number along with its corresponding gear ratio and RPM point, as well as your desired tire height. Drag racers make use of this equation for determining wheel/slick size and gear ratios to make the most out of a pass. To calculate what size tires you'll need, and effectively what wheel you'll want, multiply the proposed MPH by the gear ratio and the constant 336. Divide this by your RPM and you have a good starting point for wheel shopping.
Weight
The biggest advantage of smaller wheels is their lighter weight, compared to a dumb set of big-ass chrome dubs. Besides reducing the overall weight of the vehicle, smaller, lighter wheels also reduce unsprung weight, the weight of parts not supported by the springs-including, but not limited to, wheels, tires and brakes. Less unsprung weight translates into better handling and reduced rotational inertia
Like flywheels, cranks, clutches and axles, the lighter the rotating component, the better the acceleration. It works under braking, too. The less rotational mass to halt, the sooner you'll stop.
One-Piece, Two-Piece, Three-Piece
Two or three-piece, split rim, composite, whatever you want to call 'em, wheels like these were first developed in the 1970s. Unlike one-piece wheels, which are cast or forged from a single piece of material, multi-piece rims are constructed of either two or three pieces. Two-piece wheels are made up of a center and an outer section. The two pieces are then welded or bolted together. Three-piece rims are pretty much the same but also include a separate center disc. Wheels like these are almost always more expensive due to elaborate machining processes, as well as the manual labor required to bolt them together
Years back, one-piece forged rims were astronomically expensive-the machining involved was simply too much. Matching a forged centerpiece to a spun aluminum outer ring was a less costly alternative, hence the introduction of the two-piece wheel. Rims like these could be manufactured cheaper, were lightweight and offered flexibility and repair options far superior to their one-piece counterparts
Today, the cost issues are less significant but the flexibility of the multi-piece rim still rings true. Varying offsets, centerbores and bolt patterns can be offered simply by manufacturing a number of different center sections. Still, if weight is your main concern, it's tough to beat a good old-fashioned one-piece rim. Because they lack bolts, flanges and other structural considerations required to mate the separate pieces tighter, one-piece rims are often lighter.