wide vs. narrow wheels/tires

[nikitopo]

Originally Posted by fatoni

Okay. Show me what the tread wear of the ad08b is please. I'm not convinced that it's the same tire as the a052 and it sounds like you aren't either.

Tread wear numbers doesn't say the complete truth of the tire compound. Such numbers are based on actual road use and they are also relevant with the tire's tread depth.

Here is the original communication by Yokohama. They say that the tire meets the official Gazoo regulations. It would be a madness Bridgestone to be allowed to use the RE71R tire and Yokohama to come with a tire that had a much softer compound.



http://www.y-yokohama.com/release/?id=2881


Do you have any idea about racing regulations or are we losing our time here? In the specific races they cannot use whatever tire compound.

[fatoni]

Originally Posted by venturaII

I agree that it's likely not the same, but manufacturer tw ratings are pointless when you've got 140tw and 180tw tires one year suddenly becoming 200tw the next year..

Yeah, it's probably not the way to make my point. My point was that it seems like the compound is faster. That along with that size being a half inch shorter means that tire width and wheel width are a couple of many variables and is foolish to think you know that it's those variables instead of, imo, much more important variables like compound and drive ratios.

[nikitopo]

No, the clue is that the wheel/tire selection on the TRD 14R60 car was wrong or guided entirely by the marketing department. How many customers would buy a 6.3 million yen car with narrow tires? Are you aware that this one was inspired by the Griffon TRD 86 car which made a lap time of 58"407 at the same track? All the other equipment of the 14R60 car like the final drive/gear ratios you mentioned, the compound and all the rest of the factory modifications which it looks you are unaware were very competitive. Issue is that the wheel/tire size was too much for the specific stock power levels and in general for a car on similar power levels.

[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...
https://www.roadandtrack.com/car-cul...ransformation/

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...

[fatoni]

Originally Posted by nikitopo

No, the clue is that the wheel/tire selection on the TRD 14R60 car was wrong or guided entirely by the marketing department. How many customers would buy a 6.3 million yen car with narrow tires? Are you aware that this one was inspired by the Griffon TRD 86 car which made a lap time of 58"407 at the same track? All the other equipment of the 14R60 car like the final drive/gear ratios you mentioned, the compound and all the rest of the factory modifications which it looks you are unaware were very competitive. Issue is that the wheel/tire size was too much for the specific stock power levels and in general for a car on similar power levels.

Anyone who spends 6 million yen on a twin isn't going to pass because the wheel size. That's a stupid buy for any reason other than exclusivity and fanboyism. Performance wasn't a factor in a single one of these purchases. I spent well over 3 million yen on a car with 5.5" rims. When I was talking about ratios, I was referring to your preferred tire size being a half inch shorter at a race on thr worlds smallest race track. You don't know what you're talking about. 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?

[Tcoat]

Originally Posted by Racecomp Engineering

Compound is the #1 factor, always.

Tire width can be track dependent (for a given car).

- Andrew

Originally Posted by fatoni

Yeah, it's probably not the way to make my point. My point was that it seems like the compound is faster. That along with that size being a half inch shorter means that tire width and wheel width are a couple of many variables and is foolish to think you know that it's those variables instead of, imo, much more important variables like compound and drive ratios.

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...
https://www.roadandtrack.com/car-cul...ransformation/

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...

These ^
There is no such thing as perfect size, compound, tread, sidewall, weight and so on for tires that applies to all applications. The same tires, on the same car, on the same track can perform radically different depending on weather conditions the surface or even the layout so saying one is better than the other no matter what the application is not possible.

[NoHaveMSG]

If you wanted an example of this it would be the same brand tire, on the same car, with same setup except camber optimized for each tire width.

This comparison is like asking someone to watch me throw two different sized rocks, and then judging which one went faster.

[Capt Spaulding]

Tcoat. Don't forget the other variable - driver. Different drivers with different styles can use tires in very different ways.

[Roadcone]

treadwear numbers mean absolutely nothing. It's a HORRIBLE way to class tires.

[NoHaveMSG]

Originally Posted by Roadcone

treadwear numbers mean absolutely nothing. It's a HORRIBLE way to class tires.

You mean 200TW RS4's aren't equal to 200TW RE71R's?

Or how the GT Radial SX2 magically went from 200TW to 260TW.

[venturaII]

Originally Posted by Roadcone

treadwear numbers mean absolutely nothing. It's a HORRIBLE way to class tires.

Actually, they're not specifically classed by tw rating.

Grand Touring Summer, 240-300tw:

https://www.tirerack.com/tires/tires...iEcoContact+EP


Max Performance Summer, 340tw:

https://www.tirerack.com/tires/tires...remeContact+DW

Which one handles better?

People just assume that a lower number means stickier rubber, but it's a WEAR rating, not a grip rating. Lots of factors affect both characteristics, and classification.

[venturaII]

Originally Posted by NoHaveMSG

You mean 200TW RS4's aren't equal to 200TW RE71R's?

Or how the GT Radial SX2 magically went from 200TW to 260TW.

Or how RS3s went from 140 to 200 from one season to another?

[OND]

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

[new2subaru]

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