Model S Wheel Pricing & Performance: Std|Perf|Sig

[dadaleus]

Stopped by a Tesla store with my family today while on a road trip, and a salesperson I've known for a long time told me that the 21" wheels will have a range cost of around 5% vs. standard 19" wheels. That was news to me. I apologize if this had been said before--I was under the impression from previous discussions here that we would expect the range to be about the same vs. anything but the aero wheels. This means the aero vs. 21" wheel difference is even larger. He also claimed the 21" wheels offer handling benefits.

Anyone else heard about this range drawback to 21" wheels? If not, I'll try and confirm with Tesla via email. Trying to make final decisions as it sounds like my order will be coming up very soon: They told me they took the order for SSL #70 a few days ago.

 

[ckessel]

Anyone else heard about this range drawback to 21" wheels?

I've heard it mentioned a few times. Stickier tires, higher rolling resistance, so less range.

 

[ChadS]

the 21" wheels will have a range cost of around 5% vs. standard 19" wheels.

Recently, in the Bellevue store, I played with Tesla's range estimator. It said the 21" wheels cost 4-7 miles of range compared to the 19" wheels, depending on my other settings. That is a little over 2% of estimated range.

The tool did not include aero wheels; just the 21" and the base 19".

 

[richkae]

Recently, in the Bellevue store, I played with Tesla's range estimator. It said the 21" wheels cost 4-7 miles of range compared to the 19" wheels, depending on my other settings. That is a little over 2% of estimated range.

The tool did not include aero wheels; just the 21" and the base 19".

If that is all from aerodynamic drag ( some of it may be rolling resistance difference ), then 2% loss at 55mph will be more than 2% at 70mph.
If the aerodynamic wheels are a 5% range improvement at 55mph they will provide more at 70mph.

 

[dadaleus]

The salesperson in question claimed it was from increased "friction." But from the discussions on this thread I had the impression this wasn't likely. But I like the idea of having a better grip on the road so if this is true I'd certainly pick the sport wheels over the aeros despite the range loss. Range is important to me, but being able to stop and start faster will mean more on a day to day basis.

He also mentioned the range estimator. Hope I can get my hands on that. I wish they had it on the web.

 

[richkae]

When I get my car with the aerodynamic wheels, I will be happy to drag race anyone with the same spec car who has the 21 inch wheels.
Let's find a 1 mile drag strip.
I bet $100 that our 0-60 times will be within 1/10th of a second of each other, and I will win the mile by an obvious margin.

 

[AnOutsider]

When I get my car with the aerodynamic wheels, I will be happy to drag race anyone with the same spec car who has the 21 inch wheels.
Let's find a 1 mile drag strip.
I bet $100 that our 0-60 times will be within 1/10th of a second of each other, and I will win the mile by an obvious margin.

If we're talking performance, I thought it was about cornering and handling than straight-line acceleration? If we're talking looks then... well ya

 

[dadaleus]

When I get my car with the aerodynamic wheels, I will be happy to drag race anyone with the same spec car who has the 21 inch wheels.
Let's find a 1 mile drag strip.
I bet $100 that our 0-60 times will be within 1/10th of a second of each other, and I will win the mile by an obvious margin.

That's a test result I'd like to have in hand right now!

Also thinking stopping distance on the freeway when traffic comes to a sudden start right in front of me.

 

[Dave EV]

Stopped by a Tesla store with my family today while on a road trip, and a salesperson I've known for a long time told me that the 21" wheels will have a range cost of around 5% vs. standard 19" wheels. That was news to me. I apologize if this had been said before--I was under the impression from previous discussions here that we would expect the range to be about the same vs. anything but the aero wheels. This means the aero vs. 21" wheel difference is even larger. He also claimed the 21" wheels offer handling benefits.

Anyone else heard about this range drawback to 21" wheels? If not, I'll try and confirm with Tesla via email. Trying to make final decisions as it sounds like my order will be coming up very soon: They told me they took the order for SSL #70 a few days ago.

It certainly makes sense. In general, the larger the wheel (while keeping overall tire diameter the same), the heavier that wheel/tire combo is going to be and the less aerodynamic that wheel/tire combo is going to be.

There are NO performance cars that ship with a 21" wheel. They are simply too heavy.

Let's look a the wheel/tire specs for a few super-cars:

Bugatti Veyron ($2M) - 20" wheels
Ferrari F12 Berlinetta ($250k) - 20" wheels
Lambo Aventador - ($387k) - 19/20" wheels
Lexus LFA ($375k) - 20" wheels

Hmmm... you'd think that if there was a performance benefit to 21" wheels these guys would figure out a way to fit (and charge) for them? Cost is obviously not at issue here.

How about something a bit more similar to the Model S?

BMW M5 - 19" wheels
Porsche Panamera Turbo S - 19" wheels

Tesla's decision to offer 21" wheels is purely for show. A bit of a donky one if you ask me (Google "donk" and look at the images to get the reference). They should have offered wheels in 18-20" sizes. 18" for efficiency. 19" for performance. 20" for show.

 

[richkae]

That's a test result I'd like to have in hand right now!

Also thinking stopping distance on the freeway when traffic comes to a sudden start right in front of me.

I totally believe that stickier rubber and more contact patch will improve braking performance. The car will let you stomp on the brakes until you lock up the tires and engage the ABS - unlike straight line acceleration where you don't really explore the limit of the tire.
I don't think the same tires on a 19 or 21 will be measureably different though.

I do believe that given two same make tires - the one with lower profile ( on the 21s ) may have better cornering and handling.

 

[BYT_P1837]

Car and Driver covers that subject in this article comparing 15" to 19" tires.

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

"What’s immediately apparent from the results is that as the wheel-and-tire packages get larger and heavier, acceleration and fuel economy suffer. Neither is a huge surprise, but we measured a 10-percent drop in fuel economy and a four-percent degradation in 0-to-60-mph acceleration from the 15s to the 19s, which is worth considering should you be thinking about going big."

 

[richkae]

Car and Driver covers that subject in this article comparing 15" to 19" tires.

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

"What’s immediately apparent from the results is that as the wheel-and-tire packages get larger and heavier, acceleration and fuel economy suffer. Neither is a huge surprise, but we measured a 10-percent drop in fuel economy and a four-percent degradation in 0-to-60-mph acceleration from the 15s to the 19s, which is worth considering should you be thinking about going big."

Note that in their comparison the larger wheels also got wider and wore wider tires. The Model S tires are the same width on the 19 or the 21.

 

[BYT_P1837]

Note that in their comparison the larger wheels also got wider and wore wider tires. The Model S tires are the same width on the 19 or the 21.

I saw the rims at the Menlo Park TM store and put them side-by-side, the 21" are a tiny bit wider then the 19", maybe a half an inch wider at most.

 

[ckessel]

So it sounds like what you gain with the 21" tires is better cornering and looks.

 

[Dave EV]

So it sounds like what you gain with the 21" tires is better cornering and looks.

You will only get better cornering if the tires themselves are sticker. If you put the same tire on both a 19" and 21" wheel cornering performance will be basically identical. Acceleration will undoubtedly be better with the 19" setup.

 

[ckessel]

You will only get better cornering if the tires themselves are sticker. If you put the same tire on both a 19" and 21" wheel cornering performance will be basically identical. Acceleration will undoubtedly be better with the 19" setup.

I thought the smaller sidewall on the 21" tire gave it a bit more stiffness and helped cornering. Or that not true? Or even if true, maybe it's relatively small compared to the tire rating (stickiness)?

 

[Dave EV]

I thought the smaller sidewall on the 21" tire gave it a bit more stiffness and helped cornering. Or that not true? Or even if true, maybe it's relatively small compared to the tire rating (stickiness)?

It will make the tire stiffer, but with a good tire, it's not going to improve things significantly. You will certainly get more NVH which may make it "feel" like you are going faster. Did you see my earlier post where just about every single super-car ships with 19-20" wheels money-be-damned?

There is a point of diminishing returns (and negative returns) when up-sizing wheels. Just Google "donk".

Personally - just knowing that you'll be spending $2,000+ to replace a wear item every 15k miles or so is enough to want to go with the smaller wheel size.

Kinda defeats the purpose to buy a more "sustainable" car and then go through tires at twice the cost and twice the rate of your typical 4-door sedan.

 

[dsm363]

The 19" wheels make so much more sense. Want the performance wheels but might go with aero wheels now. Will have to think about it. Keep going back and forth on that. 19" wheels definitely give you more flexibility in tires (winter, all season....etc).

 

[ckessel]

Thanks guys. I wanted the 19" anyway, but this really cements in my mind that it's the better choice for more than just financial reasons.

 

[gg_got_a_tesla]

Given all the effort poured into building up the eco-friendly and sustainable nature of the Model S (fallen banana leaf trim and all), the choice of 21" for the perf wheels by Tesla does appear to be garish, wasteful and contradictory. Not providing a credit (or additional accessories or some such) for those wanting a downgrade to 19" for a variety of reasons seems even more rude!