2008 Subaru WRX STi
After Market Wheels and Tires
I’ve been running the basic, OEM 18 inch rims and the factory tires since I got my 2008 STi new back in March of 2008. The large rims look nice and fill the wheel well… er… well. My problem is that the low-profile sidewalls on the factory tires provide very little protection for the rims which get scratched at the least imperfection in the road.
I’ve been looking at options since before getting the car. The optional BBS rims were too expensive for my tastes and I didn’t care for the color options. Gold? Really?
Until recently most of the after market options were also outside what I was willing to pay or were styles or colors I didn’t like. Then I stumbled across a post by someone on the STi forums that talked about the TRMotorsport MT1 rims. Apparently they are made by Enkei under contract to Tire Rack and are, essentially, a rebranding of their RPF-1 Type II rims.
Left: TR MT1; Right: RFP-1 Type II
Pricing these and having heard the good reports about both the MT1 and the RPF-1 rims, the hook was set! To avoid additional problems with scratched rims and low-profile sidewalls, I chose them in a 17 x 8.5 with a Matte Grey finish.
Wrapping them in something was another interesting decision. Since my STi is a daily driver and doesn’t ever see tracks or autocrosses, I wanted something with a good grip but with an increased tread life over the factory tires. In short, the Holy Grail of tire design: the mutually-exclusive goals of excellent grip and extended tread life.
There are a lot of data sources out there, so for consistency, I’ll use http://www.tirerack.com for the following comparisons.
The factory rubber is the Dunlop SP Sport 600, which rates as:
After a bit of research I chose the Kumho Ecsta ASX which rates as:
Kuhmo may not be as Hollywood as
Once I’d chosen the wheels and tires, it was easy to make the other decisions: new TPMS sensors installed, mounted, balanced, and shipped. Tire Rack did it all for less than the difference in price between the factory basic rims and the optional BBS rims. With the extra benefit of having 2 sets of rims, tires, sensors and everything to swap out any time I want.
A few days later, UPS dropped off the packages, ready for mounting.
So it was time to get busy.
A floor jack, my impact wrench and torque wrench, some towels to protect the
wheels while laying them down, and Robert’s your Father’s Brother!
A quick, 10 minute visit at the dealership got the new TPMS sensors activated (at no cost).
Visually, they don’t fill the wheel well like the OEM rims did but functionally; I can definitely feel the improved handling. Based on what I could find, there’s a 10 pound savings PER WHEEL. (27.5 lbs for OEM standard wheels v 17.5 lbs for the 17" MT1) That’s a significant reduction in unsprung weight that transfers to easier standing starts and lighter steering response. Isn’t that what the STi is all about?
They look pretty good, too!
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