Any proof that same tires perform better on 21" wheels than the 19" wheels?

[jerry33]

These larger diameter tires reduced the sidewall flex inherent in thicker tires, and produced quicker response, better turn-in. The reduced flex also produced a cooler running tire with less pressure buildup and longer life.

That was sometimes true in the 1970s and 1980s (depending upon which tires you were comparing) when the standard tire had a 75% to 82% aspect ratio and most cars had drum brakes. Today the shorter contact patch of the extreme low profile tires is not so hot when going over an expansion joint or paint stripe when turning. As far as heat buildup goes, most is due to the flexing of the wider tread as it enters and exits the contact patch.

 

[bhzmark]

collection of skidpad results posted on the other forum:

Here are a few data points on handling performance with different wheel/tire/suspension combos:

19" wheels with the all season tires:

2014 nonP 60 with 19" Eagle RS A2 = skidpad .89 http://media.caranddriver.com/files...eview-car-and-driver2014-tesla-model-s-60.pdf

2015 nonP 70D with 19" primacy m+s = skidpad .87 http://www.caranddriver.com/tesla/model-s

21" wheels with summer tires:

2012 P85 with 21" staggered Pilot Sport PS2 tires skidpad .86g slalom 66.8http://www.edmunds.com/tesla/model-s/2012/road-test-specs1.html

2013 P85 with 21" square Conti ExtremeContact skidpad .87 (.85 w/ ESC) Edmunds slalom 63.6mph http://www.edmunds.com/car-reviews/track-tests/2013-tesla-model-s-track-test.html

2013 P85 Sig with 21" staggered Pilot Sport PS2 = skidpad .91 braking 60ft.http://media.caranddriver.com/files/2013-tesla-model-complete-specs.pdf

P+ or PD upgraded suspension with 21" and summer tires:
2014 P85+ on Michelin Pilot Sport PS2 skidpad .91g http://www.motortrend.com/roadtests...el_s_p85_vs_2014_bmw_i8_comparison/specs.html

2015 P85D with Michelin Pilot Sport PS2 skidpad .91g http://www.motortrend.com/roadtests/alternative/1411_2015_tesla_model_s_p85d_first_test/

2015 P85D with 21" staggered on unspecified tires skidpad .90g and 67.4 on Edmunds slalomhttp://www.edmunds.com/tesla/model-s/2015/road-test-specs.html

In general the main consistent improvement seems to be the move to the P+/PD suspension. And even then, the improvement is surprisingly minor. Car and Driver got .91 out of a Sig Perf.

But Edmunds only got .86g and .87g out of two different 21" shod P85s. No improvement with the 21" summer tires over the 19" all seasons.

 

[Olle]

It should also be noted that it's been said the 21s weigh more, so more unsprung weight, which hurts performance.

If you want looks, get the 21s
If you want practicality, get the 19s
If you want performance get 19s with performance tires.

Since rim damage from potholes usually happens on the inside and the looks matter on the outside, we need an asymmetrical rim and tire set up Tapered rims 19" inside and 21" outside. 45 profile inside and 35 profile outside.

Or keep it real simple and just paint some more rim with silver paint on the rubber...

 

[jerjozwik]

Since rim damage from potholes usually happens on the inside and the looks matter on the outside, we need an asymmetrical rim and tire set up Tapered rims 19" inside and 21" outside. 45 profile inside and 35 profile outside.

Or keep it real simple and just paint some more rim with silver paint on the rubber...

return of the whitewalls!

 

[linkster]

If you want looks, get the 21s
If you want practicality, get the 19s
If you want performance get 19s with performance tires.

"If you want practicality, get the 19's"
If you want performance, get the 20's (champ, Todd, "Lighted T-Man", and others)
If you want expensive (initial/towing/repair), gorgeous, low-performance, alignment sensitive, heavy, damage-prone, get the 21's
If you want to spend even more time stranded and keep Alloy Wheel Repair on speed dial, get the "rapper" 22's

 

[green1]

If you want performance, get the 20's (champ, Todd, "Lighted T-Man", and others)

Nobody has found any indication that 20s would perform any better than 19s in any way.
They are another "if you want looks" wheel.

 

[tpoltron]

Car and Driver did a pretty scientific test of wheel size a few years back and the middle profiles were the best.
Wasnt om a Model S but I think it still applies.

Effects of Upsized Wheels and Tires Tested - Tech Dept. - Car and Driver

 

[Zextraterrestrial]

Nobody has found any indication that 20s would perform any better than 19s in any way.
They are another "if you want looks" wheel.

hmm...

The best set of tires that I have found that will work on an S is probably 20" RS3 version 2's
You could run a 255/285 setup that pretty much matches stock diameters. 200 treadwear
You can also get a set of G-force rivals in a 20" 265 square setup or 265/285 that will be pretty close to stock diameter too.

other stuff that is in 19" includes the new Bridgestone RE71R, Hankook RS3, Toyo R888, and Nitto NT05 but diameters may be a touch small.

18"s would be ideal if you are looking for a performance tire but you'd be running way small overall diameter..... extra quick low end!

 

[jerjozwik]

hmm...

The best set of tires that I have found that will work on an S is probably 20" RS3 version 2's
You could run a 255/285 setup that pretty much matches stock diameters. 200 treadwear
You can also get a set of G-force rivals in a 20" 265 square setup or 265/285 that will be pretty close to stock diameter too.

hmmm indeed, i do like my RS3s...
20141122_102920 by jeremy jozwik, on Flickr

i was mulling this over with my race track friend. he brought up the tire availability issue, i did a quick look on tirerack and the 245/45R19 had many results, 245/35R21.. not so much.
but then i showed him what the 19 wheel look like and he responded with, "ewww". back on the fence i go!

 

[green1]

but then i showed him what the 19 wheel look like and he responded with, "ewww". back on the fence i go!

Just to note that the aftermarket 19in wheels look identical to the factory 21in wheels... (and the factory 19s are actually growing on me a bit... I'm debating, most likely the factory 19s would be my winter set with aftermarket 19s for summer)

 

[jerjozwik]

Just to note that the aftermarket 19in wheels look identical to the factory 21in wheels... (and the factory 19s are actually growing on me a bit... I'm debating, most likely the factory 19s would be my winter set with aftermarket 19s for summer)

yes, the t-sport line ones do, but... i have to buy them along with buying the car. that statement seemed like a couterpoint before i actually typed it out. chances are PRETTY GOOD that factory 19" + aftermarket 19" + sticky tires to wrap around them would cost less than the $4,500 tesla is charging for the 21" package.

off to t-sport and tire rack!

 

[jerjozwik]

yep... tst 19" + bfgoodrich gforce comp 2 = $2,375[ish]

seems like the pilot sport 2s are still a better tire though. lol.

 

[Zextraterrestrial]

yes, the t-sport line ones do, but... i have to buy them along with buying the car. that statement seemed like a couterpoint before i actually typed it out. chances are PRETTY GOOD that factory 19" + aftermarket 19" + sticky tires to wrap around them would cost less than the $4,500 tesla is charging for the 21" package.

off to t-sport and tire rack!

Forgestars - $1,800 - 23 lbs for 8.5/9.5 wide~ 50 lb with tires.
satggered tires
$1,100-1,200 Direzza / GForce Rival / RE71R
~ $1,200 -1,300 - R888 / RS3 V2

NT05 square setup <$1k

 

[bhzmark]

http://www.panjo.com/buy/want-to-tr...la-motors-club&utm_campaign=weeklyclassifieds

Another person looking to trade their 21" for 19" cyclones.

 

[Xenoilphobe]

19" Carbon Fiber rims outperform all others - go with the lowest weight wheel/tire package you can find. See the performance results for the $15K ones here and even lighter $8K ones here. If you are going to waste $4500 on 21 inch pretty boy rims that weight more than Fat Bastard and are "dead sexy" (in the Spy Who Shagged Me), you should go ahead and spend the extra $3500 and get the lightest rims in the world - should help increase the range a bit too. 6% increase in range would exceed the 90D vs 85D range increase, for a lower cost....

 

[bhzmark]

It should also be noted that it's been said the 21s weigh more, so more unsprung weight, which hurts performance.

If you want looks, get the 21s
If you want practicality, get the 19s
If you want performance get 19s with performance tires.

Bump and +1

 

[FluxCap]

19" Carbon Fiber rims outperform all others - go with the lowest weight wheel/tire package you can find. See the performance results for the $15K ones here and even lighter $8K ones here. If you are going to waste $4500 on 21 inch pretty boy rims that weight more than Fat Bastard and are "dead sexy" (in the Spy Who Shagged Me), you should go ahead and spend the extra $3500 and get the lightest rims in the world - should help increase the range a bit too. 6% increase in range would exceed the 90D vs 85D range increase, for a lower cost....

View attachment 100985

This is truly fascinating. I haven't tracked a car in years since I sold my Evo VIII and got my Tesla, but carbon fiber wheels seems like an amazing development.

What wheels/tires do you run on your Teslas?

 

[voyager]

Wider tires give also more rolling resistance and slightly higher drag. Wouldn't be surprised if 19" wheels with smaller tires allow for an incrementally higher top speed.

 

[Xenoilphobe]

This is truly fascinating. I haven't tracked a car in years since I sold my Evo VIII and got my Tesla, but carbon fiber wheels seems like an amazing development.

What wheels/tires do you run on your Teslas?

I have four sets for two P85's: 21's staggered that came with my P85+. (PVD Black Chromed)- for sale in my garage stored right now, 19 inch stockers will Michelin Primacy All Seasons for Winter (also PVD black chromed) on both the P85+ and the P85 and I have at set of 20x9 ESE Carbon rims on order (get them in April) they will wear Michelin Pilot Super Sport 245/40R20 (99Y) XL for summer. Once the temperatures drop below 50 degrees I will switch back to the all seasons on 19 inch rims. Weight does make a huge difference - I have a track Supercharged Miata and the lighter the wheels the faster the car feels. Check out the specs between standard aluminum and carbon rims on the fastest mustang
http://blog.caranddriver.com/tested...ts-of-the-shelby-gt350rs-carbon-fiber-wheels/

Keep in mind the Tesla 21 inch rims weigh 35 lbs!!! -- The ESE Carbons weight 12 lbs!! - losing 23 lbs of rotating mass X 4 (92 lbs) will be a significant performance improvement. The Mustang only lost ~15 lbs per corner (58 lbs total) and it had a significant impact in performance.

TEST RESULTS		ALUMINUM WHEELS		CARBON-FIBER WHEELS
WHEEL AND TIRE WEIGHT		F: 61 lb R: 61 lb		F: 46 lb R: 47 lb
ACCELERATION
30–50 MPH, TOP GEAR		10.8 sec		9.9 sec
50–70 MPH, TOP GEAR		10.5 sec		9.7 sec
30–130 MPH, 4TH GEAR		17.7 sec		16.5 sec
COAST DOWN
60–1 MPH*		139 sec 4944 feet		134 sec 4785 feet
*In neutral, to reveal differences in rotating inertia.