Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • The latest TMC Podcast (#14) is now available on YouTube and all major podcast networks. We covered FSD Beta's exciting v11 update, Enhanced Autopilot coming to the U.S. and Canada, and more!

Tesla Model Y - Things You Should Know!

jcanoe

Well-Known Member
Oct 2, 2020
5,512
6,054
Maryland
"Deep snow" is relative. If the depth of snow is less than your ground clearance, the narrow tire can improve traction, since they cut down to the road surface. In very deep snow, not so much.
That is what I meant to write; the narrow tire can improve traction when driving on snow covered roads. Deep is a relative term, I did not mean to imply that when driving in snow deeper that the ground clearance of the vehicle that narrower tires would help prevent getting stuck.
 
  • Like
Reactions: DrGriz and bfayer62

advocate8

Active Member
Nov 12, 2019
1,053
1,603
Maryland
What you say may seem logical but the statements are absolutely not true. No matter the shape of the tire, what matters is the psi, your speed and depth of water. A heavy car on either wide or narrow tires will have the same square footage (square inches ?) of contact with the pavement. The load of the car (weight) say 4000 lbs, will result in 1000 lbs borne by each tire. Each tire will deform until pressure in the tire equals pressure on it. Lets say tire pressure is 100 psi (to make the math easy). 1000 lbs divided by 100 = 10. Ten square inches of contact with the pavement will result, no matter the width of the tire.
I don't blame you for believing what you wrote. It seems logical. But physics says you are mistaken.
Yes, tire width doesn’t change the size of the contact patch, but it can change the SHAPE of the contact patch. and a wide, narrow contact patch is going to be more susceptible to hydroplaning than a narrow long one. Significantly so.
Regardless, the OP claim isn’t about that, it’s just made up or a misperception of reality.
 
Yes, tire width doesn’t change the size of the contact patch, but it can change the SHAPE of the contact patch. and a wide, narrow contact patch is going to be more susceptible to hydroplaning than a narrow long one. Significantly so.
Regardless, the OP claim isn’t about that, it’s just made up or a misperception of reality.
Believe what you wish. That's not what the physics formulas say. Calculate your minimum hydroplane speed (9 X square root of tire pressure). Stay below that speed and you won't hydroplane. Go above it and you might, if water depth is enough. Width of your tire doesn't enter into it. It's very tempting to believe various other factors are at play. Science says they are not.
 
  • Like
Reactions: Nolakai

advocate8

Active Member
Nov 12, 2019
1,053
1,603
Maryland
Believe what you wish. That's not what the physics formulas say. Calculate your minimum hydroplane speed (9 X square root of tire pressure). Stay below that speed and you won't hydroplane. Go above it and you might, if water depth is enough. Width of your tire doesn't enter into it. It's very tempting to believe various other factors are at play. Science says they are not.
Ive got half a degree in naval architecture and I can assure you the shape of the surface meeting the water absolutely is part of the equation in determining when something stops cutting through water and instead starts riding on top of it. That’s useful when understanding when the combination of surface area, water depth, weight and speed will initiate lift.
 
Brett11, please report to Tesla at least the hydroplaning problem. I encountered a scary situation like that in my RWD Model S....

Just some additional information: I hydroplaned twice with my RWD Model S in the past two years. My tires were fine though because Tesla checked them after I let them know what happened. My car got some software updates since then and the hydroplaning issue had not occurred after that. I hope it never does again...not fun at all to go through that.
 

charlesoris

2022 MYLR Red/White, 19", OD:12/13/21
Dec 11, 2021
282
219
California, USA

The three main factors that contribute to hydroplaning are:​

  • Vehicle speed - as speed increases, wet traction is reduced
  • Tire tread depth - worn tires have less ability to resist hydroplaning
  • Water depth - The deeper the water, the quicker you lose traction, but thin layers of water cause hydroplaning, too

What causes hydroplaning?​

What it boils down to is that when your tires are moving over a wet surface too quickly there is insufficient time to channel the moisture away from the center of the tire. As mentioned, the water lifts the tire and you lose traction. The point at which your vehicle becomes waterborne is called the transition point. The transition point is determined by the following variables:

  • Tire size - the wider the contact area relative to length, the higher the speed needed for hydroplaning.
  • Tread pattern
  • Tire pressure
  • Water depth
  • Water composition - oil, temperature, dirt, and salts change the water
  • Vehicle drive-train - all-wheel drive vehicles may be more likely to hydroplane in some circumstances.
  • Vehicle speed - always slow down when it’s wet. Hydroplaning can occur at any speed under the right combination of conditions, but some sources define higher speeds as over 40 mph.
  • Vehicle weight - the lighter the vehicle the greater the tendency to hydroplane.
  • Road surface type - non-grooved asphalt is more hydroplane prone than ribbed or grooved concrete
 
  • Like
Reactions: Aviateur17

advocate8

Active Member
Nov 12, 2019
1,053
1,603
Maryland
The first bullet point is obviously incorrect. But no need to believe me... quick search says popular mechanics, road and track, Nokian tires, TireRack etc argree. Much depends on the tread depth and type of water channels in treat,, but basics physics of it is straighforward.


A: Hydroplaning is a function of tire footprint, all other things being equal, a tire with a wider footprint will tend to hydroplane more. If the low-profile tire is wider, it will indeed hydroplane more easily.Aug 4, 2010

Which Tires Hydroplane More Easily? - Popular Mechanics​




From a safety point of view, both types have their good sides: On a dry road, wider tires will offer more grip than narrow ones, but the risk of aquaplaning will be higher with wide tires. – In the winter, narrow tires are better under extreme conditions as they provide higher surface pressure against the road.Apr 25, 2019
[URL='https://www.nokiantyres.com/company/news-article/wide-or-narrow-tires-here-s-how-your-choice-will-affect-driving/']

Wide or narrow tires? Here's how your choice will affect driving​

https://www.nokiantyres.com › company › news-article



Tirerack did a write up on hydroplaning, here's what they had to say:

"The speed at which a tire hydroplanes is a function of water depth, vehicle speed, vehicle weight, tire width, tread depth and tread design. It depends on how much water has to be removed, how much weight is pressing down on the tires and how efficient the tread design is at evacuating water. While deeper water, higher speeds, lighter vehicles, wider tires, less tread depth and less efficient tread designs will cause tires to hydroplane at lower speeds; all tires will be forced to hydroplane at some speed.



Tirerack did a write up on hydroplaning, here's what they had to say:

"The speed at which a tire hydroplanes is a function of water depth, vehicle speed, vehicle weight, tire width, tread depth and tread design. It depends on how much water has to be removed, how much weight is pressing down on the tires and how efficient the tread design is at evacuating water. While deeper water, higher speeds, lighter vehicles, wider tires, less tread depth and less efficient tread designs will cause tires to hydroplane at lower speeds; all tires will be forced to hydroplane at some speed.
[/URL]
https://www.popularmechanics.com/cars/how-to/a2937/hydroplaning-tires/
https://www.popularmechanics.com/cars/how-to/a2937/hydroplaning-tires/
https://www.popularmechanics.com/cars/how-to/a2937/hydroplaning-tires/
 
I've had a few BMWs in the past (3/4 series, M Sport) and although the suspension was firm, it wasn't harsh. My MY w/ 20s is somewhat jarring when going over bumpy terrain. Maybe I am just getting older and appreciate some balance.
Fair enough … but look at the cabin of your MY . How spacious is it ?

Consider its 4WD too !!

Now: compare the ride with an X3 or X5 NOT a cramped 3 or 4 series saloon !!

Ah .. 🤦‍♂️

Now the ride in the MY is definitely superior to those cars.
 
Ive got half a degree in naval architecture and I can assure you the shape of the surface meeting the water absolutely is part of the equation in determining when something stops cutting through water and instead starts riding on top of it. That’s useful when understanding when the combination of surface area, water depth, weight and speed will initiate lift.
Thanks for adding to the discussion. I think the naval architecture problem differs from the one we are discussing here with cars hydroplaning or not. In the naval architecture situation, the boat is always afloat (hopefully) and never in contact with the pavement (reef?) below, enjoying deep water below. So the naval architect is calculating the various lift of a body already fully afloat at various speeds and vessel weights. I don't have the benefit of your education but it seems to me the shape/area of the hull at the waterline will vary with the speed and weight of the vessel.
 

advocate8

Active Member
Nov 12, 2019
1,053
1,603
Maryland
Thanks for adding to the discussion. I think the naval architecture problem differs from the one we are discussing here with cars hydroplaning or not. In the naval architecture situation, the boat is always afloat (hopefully) and never in contact with the pavement (reef?) below, enjoying deep water below. So the naval architect is calculating the various lift of a body already fully afloat at various speeds and vessel weights. I don't have the benefit of your education but it seems to me the shape/area of the hull at the waterline will vary with the speed and weight of the vessel.
Well, it’s afloat before lifting. But the concept is the same.
When a tire hydroplanes it is treating the water like a solid and riding up onto it, not sinking in it and making contact with pavement as it does while rolling along slowly no matter what the depth is....

Boats are the same. People generally think of a boat as always floating but that’s not true.
For a given hull shape, there is a power at which it will lift out of the water, push over the top and skim along the surface (“planing” is the term.)
Broadly (it gets much more complicated but...) a flatter, wider shape (think wide tire with contact patch wider than it is long) requires less power and speed to plane. And when a craft is planing, it’s essentially treating the surface of the water like a solid and much of the craft normally beneath the surface rises up out of the water and skims along on the solid.
While its planing you could shoot holes in it just below the standard waterline and it wouldn’t sink... doesn’t rely on flotation at all. ease throttle though, it goes back to floating, fills with water and down it goes.
Conversely, long, narrow craft (like a narrow tire with a contact patch longer than it is wide) require less power to move quickly THROUGH the water, but require significantly more to rise onto a plane. The worst hull shape for trying to power onto a plane is a long, heavy, blade-shaped hull, typical of a sail-powered offshore cruising yacht... some I cant imagine planing at all, no matter how much horsepower or sail area you throw at them... but they eventually do.
 
What you say may seem logical but the statements are absolutely not true. No matter the shape of the tire, what matters is the psi, your speed and depth of water. A heavy car on either wide or narrow tires will have the same square footage (square inches ?) of contact with the pavement. The load of the car (weight) say 4000 lbs, will result in 1000 lbs borne by each tire. Each tire will deform until pressure in the tire equals pressure on it. Lets say tire pressure is 100 psi (to make the math easy). 1000 lbs divided by 100 = 10. Ten square inches of contact with the pavement will result, no matter the width of the tire.
I don't blame you for believing what you wrote. It seems logical. But physics says you are mistaken.
So, a run flat tire with zero psi due to a leak has an infinite contact patch since we are dividing by zero... lets say it only has 1 psi of air in it, then in your example above a standard car tire would have 1000 lbs / 1 psi... 1000 inches of contact patch.

I need to get 4 run flats and install them without air so I can out corner an F1 car!

Keith

PS: At first I thought you were joking when you came up with this "information"... now I think you are seriously trying to convince people of this... .Does anyone believe you when you claim to be an expert and spout obvious falsehoods? The thumbs up on your post may be people who are fooled or people who think they are in on the joke... not sure on that.

PPS: I expect a thumbs down from MyEarHurts... guess how much that will hurt my feelings? :D
 
Last edited:
  • Funny
Reactions: advocate8
So, a run flat tire with zero psi due to a leak has an infinite contact patch since we are dividing by zero... lets say it only has 1 psi of air in it, then in your example above a standard car tire would have 1000 lbs / 1 psi... 1000 inches of contact patch.

I need to get 4 run flats and install them without air so I can out corner an F1 car!

Keith

PS: At first I thought you were joking when you came up with this "information"... now I think you are seriously trying to convince people of this... .Does anyone believe you when you claim to be an expert and spout obvious falsehoods? The thumbs up on your post may be people who are fooled or people who think they are in on the joke... not sure on that.

PPS: I expect a thumbs down from MyEarHurts... guess how much that will hurt my feelings? :D
Sorry you don't see the logic. In your 1 psi example, the car would rest on the rims. I don't plan on debating this with you further. My only aim in posting was to convey to people a way to calculate their minimum hydroplane speed, so they could decelerate to below that speed when water pools on the road ahead. Have a pleasant day.
 

Undecided_2

Member
Supporting Member
Jan 21, 2022
474
344
Helensburgh
surely the advice should not be how fast we can drive in the rain/wet weather but how careful and slow we should drive without endangering other traffic.

This chat has reminded me of the first Mercedes A class. It used to fall over on bends until they modified it. People who owned them were told to drive slower until a fix came out.
 
  • Like
Reactions: advocate8
Sorry you don't see the logic. In your 1 psi example, the car would rest on the rims. I don't plan on debating this with you further. My only aim in posting was to convey to people a way to calculate their minimum hydroplane speed, so they could decelerate to below that speed when water pools on the road ahead. Have a pleasant day.

You talk down to people as if you are an expert, telling them that tread depth and tire width have no effect on hydroplaning (not true). You looked up a SIMPLIFIED hydroplaning formula on line and decided to play expert. The SIMPLIFIED formula make no distinction for tread depth, tread design, tire construction, rubber compound etc... it is based on a "generic" tire of "average" width with "adequate" tread depth and "adequate" water evacuation from the tread pattern and you with your internet expertise just dismiss those factors. If you are telling the truth about doing this professionally then good luck to the people relying on you.

Keith
 

Undecided_2

Member
Supporting Member
Jan 21, 2022
474
344
Helensburgh
FWIW I don't have my Y yet and sometimes have buyers remorse when I read some of the basic issues. But a good buddy of mine picked his up in October. We were texting the other day and he said it's the best purchase he's ever made and he loves the experience.


I'm hoping I'm more that experience than the OP's!
The Y is our first EV and we’re loving it. I just dropped it off at the SC and the loaner is an X (2017) Its been several hours and I miss the Y already!

No regrets from me and usually I always look for the next car after getting one.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top