wide vs. narrow wheels/tires

[NoHaveMSG]

Originally Posted by OND

I love it when people start threads to justify their purchase decisions.

Naww, he actually just likes to argue about everything.

[switchlanez]

Originally Posted by ZDan

Car went 6 tenths faster lap time on the 215/45-17 StarSpecs vs. 235/40-18. However pulled slightly more g's and quicker slalom time on the 235s...

This alone can translate to 235s being better on tracks that demand higher Gs/more slaloms.

[switchlanez]

And Daria exclaims 205 is better than 215 when she drives on this track:

[ame="https://www.youtube.com/watch?v=4tpmTgmSCWM"]BRZ on frozen lake in Lapland - YouTube[/ame]

[Impureclient]

^ Wow, she's perfection.

[rvoll]

Originally Posted by ZDan

There are WAY too many variables other than tire size to draw the conclusion: quicker because smaller tires...

Test the same car, same make/model/age/heat-cycles tire, same day, same driver, only difference being tire width, and then you have a valid comparison.

Road and Track did a test like this, but unfortunately didn't test tires of the same diameter (215/45-17 = 24.7", 235/40-18 = 25.4"), so different gearing and c.g. height. If only they'd tested a 245/40-17 vs. 215/45-17...

Car went 6 tenths faster lap time on the 215/45-17 StarSpecs vs. 235/40-18. However pulled slightly more g's and quicker slalom time on the 235s...

Yes, you need real world testing to determine which is best. But you cannot assume wider is always better. The 215's may well be better on a road course with longer straightaways because of lower wheel/tire weight and less drag. But if you're running a slalom course, the wider tire will always be better because the contact patch is much more square and you are going against much higher lateral G's.

There are many car fanboys who believe that wider is always better. In track testing alternatives, as I have done in the past, there is a sweet spot in width for each car, each track, and each pavement type -- and weather conditions. The trade-offs of wheel/tire weight and number of curves as well as engine hp make this interesting. However, the stock BRZ has only 200 hp, and good 215's, could well be the best performing tire width on the road. Put on a supercharger, and I would never go with 215's on the rear, but may well keep them on the front.

In general, people who spend money on wide tires and wheels, are just trying to justify their purchases. You can tell, because with a stock engine, there is absolutely NO reason to change the fronts, and they do. Changing the fronts make the car less responsive in virtually all cases. The backs are a different matter and there are valid arguments on both sides. But there is no argument that justifies super wide tires on a stock BRZ/86.

[fatoni]

Originally Posted by rvoll

Yes, you need real world testing to determine which is best. But you cannot assume wider is always better. The 215's may well be better on a road course with longer straightaways because of lower wheel/tire weight and less drag. But if you're running a slalom course, the wider tire will always be better because the contact patch is much more square and you are going against much higher lateral G's.

There are many car fanboys who believe that wider is always better. In track testing alternatives, as I have done in the past, there is a sweet spot in width for each car, each track, and each pavement type -- and weather conditions. The trade-offs of wheel/tire weight and number of curves as well as engine hp make this interesting. However, the stock BRZ has only 200 hp, and good 215's, could well be the best performing tire width on the road. Put on a supercharger, and I would never go with 215's on the rear, but may well keep them on the front.

In general, people who spend money on wide tires and wheels, are just trying to justify their purchases. You can tell, because with a stock engine, there is absolutely NO reason to change the fronts, and they do. Changing the fronts make the car less responsive in virtually all cases. The backs are a different matter and there are valid arguments on both sides. But there is no argument that justifies super wide tires on a stock BRZ/86.

LOL square setup is for fanboys and going staggered is for performance and responsiveness. I think we can officially say I've heard it all.

[rvoll]

Originally Posted by fatoni

LOL square setup is for fanboys and going staggered is for performance and responsiveness. I think we can officially say I've heard it all.

So if you wanted 265's in back, you should also have them in front? Really? Perhaps you should tell the Porsche, Corvette, Ferrari, and McLaren people, who obviously know nothing about sports cars, that they should have a square setup...

Before your statement, I thought I had heard it all. Is there a reason you're laughing? Is it a medical condition?

[new2subaru]

Why not...

[churchx]

switchlanez: except i'm used to 1/10th of mentioned spendings on local icetracks and she forgot to mention that good trackday or two will rip most of studs out of tires or another lifhack, which is tire rotation, for one axle driven cars. But yes, 205 or even 195 is my choice aswell for local winters.
BUT! Most of thread & arguing about was regarding dry summer tarmac track performance? For that that narrow is going overboard. It's about sweet spot, and going overboard possible at both ends of spectrum.

[NoHaveMSG]

Originally Posted by rvoll

So if you wanted 265's in back, you should also have them in front? Really? Perhaps you should tell the Porsche, Corvette, Ferrari, and McLaren people, who obviously know nothing about sports cars, that they should have a square setup...

Before your statement, I thought I had heard it all. Is there a reason you're laughing? Is it a medical condition?

To be fair, we are not exactly making Porsche, Corvette, Ferrari, or Mclaren power either.

[Cole]

Originally Posted by rvoll

So if you wanted 265's in back, you should also have them in front? Really? Perhaps you should tell the Porsche, Corvette, Ferrari, and McLaren people, who obviously know nothing about sports cars, that they should have a square setup...

Before your statement, I thought I had heard it all. Is there a reason you're laughing? Is it a medical condition?

No, the reason he's laughing is because typically, staggered set ups on twins make them more prone to understeer.

You're comparing apples to donuts. A 30k car, designed with a square set up from the factory, is far different than 75k+ cars that were designed with staggered set ups.

[nikitopo]

Originally Posted by fatoni

I spent well over 3 million yen on a car with 5.5" rims.

When did you spend this amount of money? Which decade? Nowadays a consumer has to search hard to find a 15" or 16" wheel in the US and same applies in Europe. They still keep some small sizes for the Asian market, but with the current tendency this will finish very soon.

Originally Posted by fatoni

How can the tire compound be "very competitive"? In in the video I linked before it said that the ad08b won every single race in that series. What about that is competitive?

It won every single race in the one make series, but not because of the compound. I told you there is a restriction on this. There are other factors that you can focus on a tire and this one had a very stiff structure. This plays a big role, especially if you have a high profile size. In the Gazoo races where all the cars have the same tire size it makes a difference. In a comparison with another car which has a much lower profile tire on a 18" wheel it doesn't make much difference.

But of course for you, I don't know what I am talking about.

Originally Posted by OND

I love it when people start threads to justify their purchase decisions.

Originally Posted by NoHaveMSG

Naww, he actually just likes to argue about everything.

Personally, I bought my wheel/tire combo 3 years ago. I don't have any reason to justify my choice now. Main reason was because @rvoll wanted to share some experience and almost no one wanted to listen. If you check my first post I am saying that bigger is not ALWAYS better. People should use sometimes common sense. A wheel/tire combination that will give you more traction, will give you also more friction. This means that you will have better corner exit speeds, but much worse acceleration. It is a balance thing and on the specific track it looks that bigger is not optimal on a stock power level car.

[nikitopo]

Originally Posted by new2subaru

If 205's are good why not go down to 195?

It is about keeping a balance.

[fatoni]

Originally Posted by nikitopo

When did you spend this amount of money? Which decade? Nowadays a consumer has to search hard to find a 15" or 16" wheel in the US and same applies in Europe. They still keep some small sizes for the Asian market, but with the current tendency this will finish very soon.


It won every single race in the one make series, but not because of the compound. I told you there is a restriction on this. There are other factors that you can focus on a tire and this one had a very stiff structure. This plays a big role, especially if you have a high profile size. In the Gazoo races where all the cars have the same tire size it makes a difference. In a comparison with another car which has a much lower profile tire on a 18" wheel it doesn't make much difference.

But of course for you, I don't know what I am talking about.




Personally, I bought my wheel/tire combo 3 years ago. I don't have any reason to justify my choice now. Main reason was because @rvoll wanted to share some experience and almost no one wanted to listen. If you check my first post I am saying that bigger is not ALWAYS better. People should use sometimes common sense. A wheel/tire combination that will give you more traction, will give you also more friction. This means that you will have better corner exit speeds, but much worse acceleration. It is a balance thing and on the specific track it looks that bigger is not optimal on a stock power level car.

I bought it in 2018. The tire you're talking about was designed specifically for 20" rims and it was record breaking there too. if that tire won every race, other tires aren't competitive. That's the opposite of what the word competitive means.