Quest to improve Efficiency and improve braking

[thevaibhav]

Background : have a 2017 MX 100D bought it used in august 2019 and love the car. but there are few quirks and issues SC wont address and hence driving me to look for solutions..

Brakes : use the regen most of the time and hardly use the brakes, that said there were 2 close calls where I really had to break hard, but felt the car did not stop as quickly as I am used to with other cars ie 2019 XC90 or Acura MDX 2015 (I have new continental DSW06, so unlikely its a tire issue).. I also have a lot of noise coming from the brakes it high during the morning and gets lower with driving, but find it irritating nevertheless..

WH/M : for a 100D all I get in the real world is about ~200 miles.. at 100% the car shows 274miles.. most of my driving is I95 or turnpike and is in the 65 to 75MPH range.. my consumption is about 415Wh/m and i am trying to reduce that.. I know my 21` wheels dont help the cause..

So to address the above 2 issues, was considering replacing the bearing inside the hub with Ceramic.. Link to the product attached. Tesla Model S/X Performance/High Efficiency Wheel Bearings

Also have heard reducing unsprung weight helps with the efficiency.. So was thinking to get GEOMET replacement rotors with Ceremic brake pads https://evtuning.com/collections/mo...tesla-model-s-2012-2016?variant=8104492499048

Looking to find out if anyone on the forum has any experience with either of these products ?

 

[VikH]

Your 22" wheels are probably causing the brake noise (look up 22" wheel resonance) and poor efficiency wh/m. Change the wheels for something smaller, lighter, and tires with low rolling resistance.

Regarding your suggestions, I have not seen anyone run tests on swapping out bearings (although I believe the Ravens have updated wheel bearings).

 

[jboy210]

Slowing down is a good way to get more efficiency. EPA Highway mileage test tops out at 60 mph. And drag increases with the square of speed. I believe 22" wheel cost 10-15% on range.

 

[ReachX]

All per google:

2019 Volvo XC90 weight: 4,394 lbs
2015 Acura MDX weight: 4,332 lbs
2017 Tesla Model X 100D weight: 5,267 lbs

These X are heavy. No way around it. I too have experienced 'pucker' braking in the X and it just takes longer/further to slow this car than most other vehicles. Driving style must adapt to it. My other car is a 2900 lbs roadster, the difference is night and day.

I think the ceramic bearings will be an infinitesimal benefit and not impact anything measurable. As long as the original bearings are in good condition and not making noise themselves I would not change them. Those rotors you linked to are inferior to the ones already on the car, and I wouldn't touch them. The only 'upgrade' would be to move to a true 2-piece floating rotor with a lighter hat design, such as: These EBC rotors. I still wouldn't recommend doing so until stock rotors wear down and need replacing on your own dime.

I agree with the above post. The very best change you could make would be to swap your larger, heavier wheels to OE 19" or 20" wheels and tires or lightweight aftermarket wheels and tires of an 19" or 20" size. That will make the largest difference in range and braking as you provide the highest reduction in unsprung weight per dollar spent. (2nd would be the 2-piece floating rotors)

 

[SSedan]

Aftermarket wheels are likely to compromise aerodynamics undoing any gains from weight savings.

On rotors lighter hats is so close to center as to make for no gains. Performance rotors are about taking more heat and managing it better. Brake heat is not an issue in normal driving, a single panic stop is not a big deal, aftermarket brake cope better with repeated heavy application of brakes.
20" rims with a little more sidewall might help braking by keeping the tire in better contact with the road, tall rims are more prone to skipping and losing contact, sidewall is part of your suspension.
Hyper efficient tires are not going to be as grippy and will lengthen stopping distance though so there is a balance to be struck.

Maybe the first thing would be make sure the pads are lubed and floating right. If the pads bind in the caliper it causes excess travel before they actually grip the rotor.

Rotating weight is of minimal concern for sustained highway cruise, is a concern with acceleration/deceleration but a lesser concern in EVs range wise since regenerative braking can recover much of it. Would help panic braking though.

 

[thevaibhav]

Slowing down is a good way to get more efficiency. EPA Highway mileage test tops out at 60 mph. And drag increases with the square of speed. I believe 22" wheel cost 10-15% on range.

On the Turnpike that i have to use daily the speed of cars around me is 65 to 75.. so slowing down might not be an option.. but ill have to look at new tires and wheels !! Sucks as i just had to pay over $3500 to get the front 2 replaced as there was a lot of vibration.. there was no wheel damage that was visible and balancing machine also said they were ok !!

News for Model X owners with the dreaded shudder

 

[jboy210]

On the Turnpike that i have to use daily the speed of cars around me is 65 to 75.. so slowing down might not be an option.. but ill have to look at new tires and wheels !! Sucks as i just had to pay over $3500 to get the front 2 replaced as there was a lot of vibration.. there was no wheel damage that was visible and balancing machine also said they were ok !!

News for Model X owners with the dreaded shudder

Maybe out of round. Hitting a pothole or rock or even a speed bump too hard will bend a rim. And the larger the diameter and lower profile the tires the more easily they bend. They still balance fine, but when they spin they create a nasty vibration. It is one of the reasons that while I like the appearance of low profile wheel and tires, I never buy them.

 

[thevaibhav]

All per google:

2019 Volvo XC90 weight: 4,394 lbs
2015 Acura MDX weight: 4,332 lbs
2017 Tesla Model X 100D weight: 5,267 lbs

These X are heavy. No way around it. I too have experienced 'pucker' braking in the X and it just takes longer/further to slow this car than most other vehicles. Driving style must adapt to it. My other car is a 2900 lbs roadster, the difference is night and day.

I think the ceramic bearings will be an infinitesimal benefit and not impact anything measurable. As long as the original bearings are in good condition and not making noise themselves I would not change them. Those rotors you linked to are inferior to the ones already on the car, and I wouldn't touch them. The only 'upgrade' would be to move to a true 2-piece floating rotor with a lighter hat design, such as: These EBC rotors. I still wouldn't recommend doing so until stock rotors wear down and need replacing on your own dime.

I agree with the above post. The very best change you could make would be to swap your larger, heavier wheels to OE 19" or 20" wheels and tires or lightweight aftermarket wheels and tires of an 19" or 20" size. That will make the largest difference in range and braking as you provide the highest reduction in unsprung weight per dollar spent. (2nd would be the 2-piece floating rotors)

Thank you for your detailed response.. Ill be honest the last time i had to hit the brakes hard was bit of a panic and i dont really want to get there again.. i was lucky that there was a shoulder open and i drove onto it to come to a stop 1 car length later !

I was looking into the rotors, but no one seems to have "SG2FC2141" in stock.. ill call EBC to see which distributor has them.. Would you also be able to recommend any kind of brake pads ?

As soon as the current tires run out, ill replace with 19"

 

[thevaibhav]

All per google:

2019 Volvo XC90 weight: 4,394 lbs
2015 Acura MDX weight: 4,332 lbs
2017 Tesla Model X 100D weight: 5,267 lbs

These X are heavy. No way around it. I too have experienced 'pucker' braking in the X and it just takes longer/further to slow this car than most other vehicles. Driving style must adapt to it. My other car is a 2900 lbs roadster, the difference is night and day.

I think the ceramic bearings will be an infinitesimal benefit and not impact anything measurable. As long as the original bearings are in good condition and not making noise themselves I would not change them. Those rotors you linked to are inferior to the ones already on the car, and I wouldn't touch them. The only 'upgrade' would be to move to a true 2-piece floating rotor with a lighter hat design, such as: These EBC rotors. I still wouldn't recommend doing so until stock rotors wear down and need replacing on your own dime.

I agree with the above post. The very best change you could make would be to swap your larger, heavier wheels to OE 19" or 20" wheels and tires or lightweight aftermarket wheels and tires of an 19" or 20" size. That will make the largest difference in range and braking as you provide the highest reduction in unsprung weight per dollar spent. (2nd would be the 2-piece floating rotors)

Thank you for your input and suggestion.. finally found the EBC rotor (SG2FC2141) with a US supplier.. have also ordered the EBC Yellowstuff DP43028R brake pads.. Wait is about 4 weeks..

 

[K_KCB]

Thank you for your input and suggestion.. finally found the EBC rotor (SG2FC2141) with a US supplier.. have also ordered the EBC Yellowstuff DP43028R brake pads.. Wait is about 4 weeks..

Where did you find the set? Are you planning to DIY it?

 

[Sandiegodoug]

We have a 6/17 x100d. Usually, we average around 340 w/m. Have 20s and leave range mode on. Mix of 65-70 freeway and stop and go.

 

[thevaibhav]

Where did you find the set? Are you planning to DIY it?

Found it on perfectbrakes.com

once they are here will take them to tire kingdom or someone like them to install

 

[K_KCB]

Found it on perfectbrakes.com

once they are here will take them to tire kingdom or someone like them to install

Thanks, love to know if the unspring weight has any impact to energy usage! What did you get for the rear to match?

 

[ElectricSteve]

Brakes : use the regen most of the time and hardly use the brakes, that said there were 2 close calls where I really had to break hard, but felt the car did not stop as quickly as I am used to with other cars ie 2019 XC90 or Acura MDX 2015.

Time to explain how friction brakes work. A major contributor that makes friction brakes work, is a thin film of fresh friction material that the pads leave behind on the rotors. Also, friction brakes work better when warm, even better when hot (but not hotter than the rotors and pads are designed for).
This "film" is left behind when a friction brake is used when the pad rubs over the rotor.

We hardly use our friction brakes...

Thus we don't get the same kind of build-up of this friction-material on the rotors. When we DO use the friction brakes (emergency stop for example), our brake-rotors need a couple of rotations to build up the thin film and heat up before they really start to work.

If we would use our friction brakes much more often (by setting re-gen to "low" for example, or just drive like a madman/manwoman/madinbetween), our friction brakes would work the same as other similar vehicles. We have massive 4-piston Brembo brakes but they need to be warm and have a fresh layer of friction material to be used to their full potential.

So let's re-cap. Our brakes are stone-cold most of the time and we seldomly have a fresh layer/film of friction-material on the rotors. It is therefore perfectly logical and expected that our brakes do not have that "initial bite" and powerfull brake feel as ICE cars. Because it is completely normal, the SC cannot do anything.
One could argue that they should have told you what I just told you though, so that you knew what to expect.

For all of you that are hoping for better results with other brake rotors and pads, as long as the brakes are stone-cold and do not get the chance to put down a fresh film of friction material often enough, they won't be (much) better.
Do you seriously think that Brembo makes sub-standard brakes?? Do you know who Brembo is?
A couple of years ago, the Model S was found to be on a par with the BMW M5 model from that time when it came to braking. But of course, those brakes were all nice and hot and freshly used.

Those GEOMET replacement rotors with Ceremic brake pads will only cost you a bundle and will hardly put a dent in your consumption.
Get the slotted version. It helps with scraping grime of rotors and thus putting down a fresh layer of friction material. Holes in brakes helped with cooling in the past but are just for optics nowadays, hardly helping with cooling to to the design of modern rotors. They actually reduce braking-performance because there is less "rotor to pad contact area".
But even when you mount the slotted ones. If you hardly use the friction brakes, those slots will not get used either so the whole "scraping and refreshing the friction-material effect" will be reduced a great deal.

Also, you better make damn sure that those rotors are heat-treated because normal rotors will wear like butter if they are not. The X is a HEAVY car and those brakes get HOT.

Ceremic brake pads need to be heated up properly before they start to really work (unless they invented the rainbow farting unicorn pad material). And heating up brakes is exactly what EV using high re-gen DO NOT do very well.