Every tire test we conduct represents but a single data point, and though we try to minimize variables in our comparison process, there will always be the chance that different results will be obtained with different weather, venue, driver, vehicle and setup. So what do we do? Test again.
Round 1: Yokohama vs. Hoosier
We were given permission to share partial results from our private developmental work that compared a new tire to both the Hoosier R7 and Yokohama A055. In that test, the prototype tire was run at both the beginning and end of the test, and while we can’t divulge the actual data, the two sessions produced similar results, so we’re confident that we successfully minimized variables in our comparison.
For logistical reasons, we lapped Harris Hill Raceway, our usual track for tire testing, in the atypical counterclockwise direction. Weather was cloudy throughout with temperatures hovering in the low 70s.
Yokohama Advan A055
- size: 245/40R17
- fastest lap: 1:25.02
The Advan A055 came up to temp rather quickly, and full grip was available after about a lap and a half. Steering response was extremely progressive, with small inputs making increasingly larger turning moments as cornering loads increased.
Breakaway was a little edgy, especially at the rear of the car. This required constant attention to consistently drive at the limit, but the tire’s pace never slowed. Looking at the data, there was no more than a tenth or two available by combining the best sections.
- size: 225/40R17
- fastest lap: 1:25.08
The R7 took several laps to build heat and fully activate the compound. Driving characteristics were very natural: medium response, progressive breakaway. The tire was especially good at combined loading asks–like trail-braking along with corner-exit power-up.
Handling balance shifted to a slight oversteer, though, resulting in a spin on the fourth lap in Turn2. It’s an especially tricky section to get consistently in the clockwise layout, requiring trail-braking, a downshift and a subsequent power squeeze just as the car crests some bumps. Add tire swaps to the equation, and mistakes can happen.
Unfortunately, the spin overheated the rear tires, and subsequent laps did not deliver the same level of grip. Looking at the data, though, the quickest lap had all the best segments.