The Benefits of Width - Why We Prefer 15x9 Sizing

There has always been a fair amount of skepticism around the ability of using a wider wheel and tire setup.  Whether it be a street car, or a dual-purpose car to enjoy at the track on weekends, the apprehension arises around the thought of damaged fenders or rubbing tires on your pride and joy.

Well, we're here to tell you to cast those doubts aside, because in reality, it's not that difficult at all, and the benefits gained from utilizing a wider tire far surpass the effort (not to mention the added aesthetic qualities).

 In the case of the application of a 15x9 (+33/+30 for Group B specifically) wheel on a popular sport compact, such as a Civic, Miata, or MRS, there are an array of methods in our arsenal that would allow us to push the boundaries of the typical go-to 195 or 205 series tire, to something with a much larger contact patch.  Having a larger tire under your fender is beneficial simply by increasing the contact patch.  Where a 225/45/15 or even a 245/40/15 setup on a sport compact car was unheard of a few years ago, it's becoming more and more common place in today's automotive world.  We've tailored our sizing and offsets to this fact, recognizing the lack of options in these sizes currently and the need/demand for more.

We've also come across many drivers at the track that praise the use of a staggered setup; that is, a larger sized tire on the drive wheels. Typical staggers include a 245 front 225 rear on FWD Hondas, or 225/245 rear, 205/225 front on RWD roadsters - but surely aren't limited to those combinations.  A staggered setup will generally result in more grip on the drive tire, allowing you to put power down sooner on corner exit. It can also help tune the balance of the car by assisting in the reduction of understeer/oversteer depending on the cars configuration.

Andrew Horn on staggered Group B NC-01 - 15x9 245/40,15x8 225/45 rear - aftermarket fenders

Jose Mejia on staggered Group B NC-01 - 15x9 245/40,15x8 225/45 rear - oem fenders

Whether square or staggered, it simply comes down to having more tire equating to more grip - and that's a good thing whether on the street or putting down laps at the track. 

It's easy to see why a larger tire is better - but maybe we all already knew that.  So how do we stuff all that rubber under the small fenders of your hatchback?  While we highly suggest the use of adjustable arms to ensure accurate alignment specs, it is good to note that in a double-wishbone suspension, camber curves increase exponentially as the car lowers in ride height.  In the case of a vehicle with MacPherson strut, that curve becomes more linear, which is why double wishbone is the preferred type for vehicles that will get used on track. Regardless, natural camber is an easy and affordable way to fit a larger tire.  For a technical analysis comparing the two types of common suspension (double wishbone and McP), see this study done by the IJRTE. 

If camber (natural or adjustable) is the easiest route to go in fitting a larger tire, the next easiest step would be either to get an aftermarket fender or flare, or for those that prefer the OEM look, rolling or trimming the fender.  There are several professional services that are able to provide the service of rolling or trimming without sacrificing the looks, resale value, or durability of the fender.  It's also something you can do yourself with relative ease as long as you have patience.  If rolling the fender isn't quite enough, the next step would be to pull the fender which we recommend having a professional perform.  At that point there is risk of damaging the paint, as well as the fender itself. 

Wheel spacers may be used for issues with inner clearance, however our offsets are created with this in mind.  Depending on your application, and use of wheel spacers, you may also want to consider extended studs

For very aggressive tire sizing, you should be prepared to trim or cut parts of the fender or inner well, removing liners, and modify certain parts of the area.  We suggest consulting a trusted shop before performing any of the aforementioned.

All things considered, the benefits of increasing tire width far outweigh what's required to fit them.  There are many misappropriated opinions or thoughts about what is possible on these chassis', but the bottom line is that it is very possible to fit a wider tire, and the 15x9 is the wheel that provides the most versatility in doing so.