POLL: What will my 60-0 stopping distance be with Pilot Sport 4S 265/40R18s be?

[Daniel in SD]

I measured my stopping distance using a VBOX sport today with the stock MXM4 tires. I got 126ft and 123ft in back to back runs (3 mins apart). This week I'm getting 265/40R18s Pilot Sport 4S tires mounted to 18x9.5 TSW Bathurst rims. What do you all think my stopping distance will be? My guess is 98 feet.

 

[Knightshade]

The 235 20s get 99 supposedly, so yeah your guess is probably a pretty solid one.

Also please let us know 2 other data points-

What this does to your range... MPP suggests you might see something like a 20% hit with wide/sticky wheels and tires.

And how clearance looks- I only know one other Model 3 owner with that setup (the dude in Hawaii) and there's second hand reports of no rubbing but not much hard data beyond that.

 

[Daniel in SD]

The 235 20s get 99 supposedly, so yeah your guess is probably a pretty solid one.

Also please let us know 2 other data points-

What this does to your range... MPP suggests you might see something like a 20% hit with wide/sticky wheels and tires.

And how clearance looks- I only know one other Model 3 owner with that setup (the dude in Hawaii) and there's second hand reports of no rubbing but not much hard data beyond that.

Yeah. The range hit is not going to be pretty. I'm already getting 290Wh/mi over the life of the car and that's with the aero covers on!
The wheels are 18x9.5 with 39mm offset. I test fit one on the front and there is only 4mm of clearance to the knuckle. Because of the way it curves 18's are tighter fit than larger wheels. I don't think tire clearance will be a problem from what I've read about other people's setups.

 

[juanmedina]

Yeah. The range hit is not going to be pretty. I'm already getting 290Wh/mi over the life of the car and that's with the aero covers on!
The wheels are 18x9.5 with 39mm offset. I test fit one on the front and there is only 4mm of clearance to the knuckle. Because of the way it curves 18's are tighter fit than larger wheels. I don't think tire clearance will be a problem from what I've read about other people's setups.

Off topic. Can you weight your new wheels and tires? I am curious about how it compares to the stock 18s. I can't wait to see the pics. I thought you were getting Enkei Raijins

 

[Daniel in SD]

Off topic. Can you weight your new wheels and tires? I am curious about how it compares to the stock 18s. I can't wait to see the pics. I thought you were getting Enkei Raijins

I was going to get the Raijins but I really wanted the gunmetal color and they don't make them anymore. I just got them mounted today (off the car, I don't want a jack point disaster!) and I'll put them on the car tomorrow morning. I think the wheels are about 20lbs but I'll try to remember to get the total weight. I might have to wait until this weekend to get the braking distance. It's very important that no one is following me!

 

[ElectricGhost]

I measured my stopping distance using a VBOX sport today with the stock MXM4 tires. I got 126ft and 123ft in back to back runs (3 mins apart). This week I'm getting 265/40R18s Pilot Sport 4S tires mounted to 18x9.5 TSW Bathurst rims. What do you all think my stopping distance will be? My guess is 98 feet.
View attachment 345881

Really excited to see your result! I'm looking to get 265/35/19s in the future.

 

[ElectricGhost]

Please do some 0-60 runs before/after too

 

[gilscales]

Waiting for results here as well!

 

[AlanSubie4Life]

So 265/235=1.13 is roughly 13% wider cross section. I guess that linearly scales the braking force? So I'll say they're also just a little stickier compound (~5%) and provide 19% more braking force due to width increase and stickiness. That gives 125/1.19 = 105 feet. Braking distance is d = v^2/(2*a). Works out to 1.15g if it's 105 feet. 98 feet would be 1.23g. I guess we'll see how much stickier they are!

 

[Daniel in SD]

So, the results are a little disappointing. An average of about 105.5 feet with the PS4S tires and 124 feet with the MXM4s. I thought it would be a little better given how sticky they feel. @AlanSubie4Life is getting a P3D+ so maybe we can test it back to back to see how they compare. Depending on the results maybe we could even swap wheels and see what happens!
Actually now looking at the Motortrend review they did record a braking distance of 105 feet on one of their runs (100,105,99) so maybe I'm not that far off and if I had done a few more it would have gotten better... Obviously the road surface matters a lot too.
So far I'm getting 350Wh/mile vs. 290Wh/mile with the aeros. I may be driving a little bit more aggressively though . Looking forward to the increased regen that's supposedly coming in the next update.
On a sad note I noticed that one of the wheel studs is damaged. It looks like there is a defect in the lug nut. I guess I'll have to schedule service and try to get them to replace the hub (the studs do not appear to have a separate part number, what a waste).

 

[AlanSubie4Life]

As you said, my assumption of the braking force scaling with tire width probably isn’t correct as presumably the contact patch is the same area for the same pressure. But, fortuitously, I turned out to be close anyway. The PS4S tires are a lot stickier! 1.15g!

The sub-100 distances reported elsewhere...I wonder whether they are doing a stop from 70 like you are? There is some initial heat up of the tire I suppose, if you start from 70. It’s 36% more energy to dissipate. Doubt it makes a difference, but suppose you could try stopping from 65, to see if there is any change.

Looking forward to comparing whenever I finally get my P3D+! I’m sure it will stop faster, since it has those bigger brake calipers...and we know that’s what really matters here! Depending on how it does, might be interesting to swap wheels.

 

[Daniel in SD]

As you said, my assumption of the braking force scaling with tire width probably isn’t correct as presumably the contact patch is the same area for the same pressure. But, fortuitously, I turned out to be close anyway. The PS4S tires are a lot stickier! 1.15g!

The sub-100 distances reported elsewhere...I wonder whether they are doing a stop from 70 like you are? There is some initial heat up of the tire I suppose, if you start from 70. It’s 36% more energy to dissipate. Doubt it makes a difference, but suppose you could try stopping from 65, to see if there is any change.

Looking forward to comparing whenever I finally get my P3D+! I’m sure it will stop faster, since it has those bigger brake calipers...and we know that’s what really matters here! Depending on how it does, might be interesting to swap wheels.

One of the runs was from 62.8mph. The only measured distances I found were from Motortrend. As for rotor sizes we all know that having the Michelin Premium Touch Design® sidewall is the key to shortening stopping distances!

 

[Knightshade]

Thanks for the data.... curious to see if your efficiency changes as you get used to the tires a bit more...

I'm assuming 0-60 didn't change? (as it seems it doesn't swapping between 18" MXM4s and 20" PS4s on the Ps)

Any comments on handling difference?

I'm still kind of torn between 265/40-18s and 235/45-18s in sticky tires once the weather warms up again.... not sure how much range hit is the width vs just the tire compound...or how much the two would differ in actual performance with the same compound

 

[Daniel in SD]

Thanks for the data.... curious to see if your efficiency changes as you get used to the tires a bit more...

I'm assuming 0-60 didn't change? (as it seems it doesn't swapping between 18" MXM4s and 20" PS4s on the Ps)

Any comments on handling difference?

I'm still kind of torn between 265/40-18s and 235/45-18s in sticky tires once the weather warms up again.... not sure how much range hit is the width vs just the tire compound...or how much the two would differ in actual performance with the same compound

They definitely stick a lot better and make fewer screeching noises. Ride quality and noise is only a hair worse. They’re good street tires.
I think the extra width and open spoke design probably creates a lot of extra drag. They stick out a little past the fenders in the front which can’t be good for aero. There’s probably a reason the stock wheels are so inset. They look so good though!
I didn’t measure 0-60 again but I don’t see how it could be any different.

 

[AlanSubie4Life]

I missed the stop from 63. Makes no difference; not too surprising. The premium touch sidewall will definitely help though, along with the large calipers and rotors. That's kind of a strange picture they use to advertise it.

Another consideration for people wanting stickier tires - they do tend to throw up a lot more road debris (small pebbles primarily), and with the wider stance, that road debris tends to get thrown up at the side of the car. Consider some strategically placed PPF if you don't have any on the car. You also tend to hear these pebbles pelting the side of the car and the wheel wells.

Since this stopping time is about 2.5-2.6 seconds, and the prior tires were around 3 seconds, it's not likely that 0-60 times that are in the 3.2 second range would be affected by this particular tire change. The acceleration isn't completely constant on the 0-60 runs, but it's pretty close, and I don't think it ever exceeds the 0.96g that the MXM4 is capable of, when stopping. (0.96g would be a 2.85 second 0-60 run...doesn't align exactly with the ~3 second 60-0 stopping time, presumably because of that weird tailing off at the very end of the 60-0 stops).

Maybe if people want to break the tires loose on their 0-60 runs they should try the Ecopias? They also have the benefit of better efficiency, so it's a win-win!

Or, Tesla can increase the initial motor torque by about 10% to break the MXM4s loose...maybe Elon can give that *exclusively* to ONLY the early P3D adopters, rather than giving them 5k back in his special Friday night ~$50 million giveaway? As a stockholder, I'd prefer that, though as a future P3D+ owner, I'm not as enthusiastic about the exclusivity aspect. We know those early adopters have the special double burn in motors & drive electronics, so they should be able to take the extra current, am I right?

 

[240W]

Avg ~240 with aeros off, roughly the same (only 100 miles thus far) with 255 ps4s. A lot of stop and go traffic nets me the lower number thanks to regen. The grip is noticeable better. I want 265 next, lol

 

[ElectricGhost]

Some useful info in this

“The Model 3 stopped from 70 mph in 147 feet where all the gas-burning competitors needed at least 150. The Tesla produces strong deceleration from the regenerative system as soon as the driver lifts off the accelerator, even before applying the left pedal to bring the friction brakes into play. Also credit the grippy performance tires and upgraded brakes—the regular rear-drive Model 3 with the standard brakes and shod with all-season tires on 18-inch wheels produced only 0.84 g of lateral grip and needed 176 feet to stop from 70 mph”

2018 Tesla Model 3 Performance – Accelerative Excellence

 

[AlanSubie4Life]

The Tesla produces strong deceleration from the regenerative system as soon as the driver lifts off the accelerator, even before applying the left pedal to bring the friction brakes into play. Also credit the grippy performance tires and upgraded brakes

I wish they wouldn’t credit the large rotors and brakes - it perpetuates the myth that larger brakes/rotors are useful for non-track use - the rotors/calipers likely have no effect on stopping distance for a single stop. However, to be sure, I’ll test it once I get my car, and see how it compares to Daniel’s car at the same time and place and same Vbox. State of charge likely has no effect because the claim is that tires are all that matters, but we can control for that too.

I suppose larger brake pads would last a bit longer, but they should last forever in any case, for someone driving the car efficiently.

 

[SigNC]

While I agree either brake package is fine for a one time max braking effort. Having driven both a 3 with regular brakes and the upgraded brakes, the upgraded brakes give you a lot more feel and confidence when slowing. I'm fully aware each will get you stopped fast in a single event but the upgraded ones take much less effort to slow you down when needed.

 

[Daniel in SD]

Some useful info in this

“The Model 3 stopped from 70 mph in 147 feet where all the gas-burning competitors needed at least 150. The Tesla produces strong deceleration from the regenerative system as soon as the driver lifts off the accelerator, even before applying the left pedal to bring the friction brakes into play. Also credit the grippy performance tires and upgraded brakes—the regular rear-drive Model 3 with the standard brakes and shod with all-season tires on 18-inch wheels produced only 0.84 g of lateral grip and needed 176 feet to stop from 70 mph”

2018 Tesla Model 3 Performance – Accelerative Excellence

147 feet 70-0 should be about 108 feet when scaled to 60-0 (147*(60/70)^2=108).
176*(60/70)^2 = 129 feet so pretty much in line with my measurements.
I would bet that the feel of the brakes is more a function of the pad compound than the size of the brakes. Obviously bigger brakes are better for repeated stops.