Wheels and Tires article: May 2012

Hello everyone,

First time poster, long time subscriber. I enjoyed the short article in the May 2012 issue about up and downsizing but I would to hear some feedback about two things. I know it would have significantly increased the testing required for the article but would it not have been helpful to also include a 19" combo? Lest people continue saying, as they have been, "If 18s are faster than 17s, 19s must be faster still!"

Also, I commend the effort taken to find a 17" wheel that would make the 17' combo weigh the same as the 18" combo but a more realistic choice would have been to include the 17" OZ Alleggeritas which would be around 15 lbs. The test as it was conducted proves that for this car, with these drivers, and with these specific wheels and tires that an 18" combo will provide slightly better ultimate grip, better manageability, and better lap times than a 17" combo of the same weight. What it does not tell us is how lap times and the car's demeanor are affected when a smaller wheel of the same construction(and lower weight) is used. This, for me, is the crucial piece of information.

Just my 2 cents,

Matt

Thanks for the feedback, and thanks for joining our forum. To be honest, it's hard to do a tire test that appeals to everyone, but we do our best to generate useful data. We decided to make this one an A-B test to answer one particular question. Plus, we also recently did a pretty in-depth plus-size comparo with our MX-5.

Add more sizes to a test? Well, now we're talking about testing tires over a long span of time. What if the pavement heats up or cools down due to weather changes? Or, what about driver fatigue?

Here's one for you. A while back we were looking doing a similar test--testing the same model of tire over different sizes. I forget the details, but turns out that the tire company used two different construction techniques--larger sizes had one makeup while the smaller one used another. So, while the model name and looks were consistent across the line, the tire guts were in fact very different. We would have basically been using two different tire models for the test. I pulled out some hair on that one.

David S. Wallens wrote: So, while the model name and looks were consistent across the line, the tire guts were in fact very different. We would have basically been using two different tire models for the test. I pulled out some hair on that one.

That's a really annoying practice for manufacturers to follow.

JoeyM wrote:

David S. Wallens wrote: So, while the model name and looks were consistent across the line, the tire guts were in fact very different. We would have basically been using two different tire models for the test. I pulled out some hair on that one.

That's a really annoying practice for manufacturers to follow.

This throws my entire world into chaos.

JoeyM wrote:

David S. Wallens wrote: So, while the model name and looks were consistent across the line, the tire guts were in fact very different. We would have basically been using two different tire models for the test. I pulled out some hair on that one.

That's a really annoying practice for manufacturers to follow.

Well, I don't think they do it to mess with my tire tests. I can see their side, too: A 185/60R14 tire has different load requirements than a 275/40R20, for example.