Bjørn Descends 18% Grade In Tesla Model X Without Brakes

JUL 23 2018 BY WADE MALONE 29

Bjørn coasts his Model X down Stalheimskleiva in Norway without touching either pedal.

Arguably, one of the best aspects of electric vehicles is regenerative braking. Turning on high regenerative braking is not necessarily the most efficient means of travel in every scenario. But it does make for a more relaxing driving experience once you get a feel for it.

Bjørn decided to put his Tesla to the test by taking it down Stalheimskleiva, a one way road in Norway known for it’s relatively steep 18 % grade descent. While far from the steepest road in the world, it is one of the steepest in Europe. Bjørn compares it to Lombard Street in San Francisco. For his test, he neither accelerates nor brakes and the Model X is set to maximum regen.

Bjorn-descends-no-brakes

Was his Model X able to pull it off? Well, there are a few tense moments when the car gained speed just before a turn. And during the short drive he suggests that the Ampera-e might be better suited to this due to it’s higher regenerative braking. But as the car safely reaches the end of the road, Bjørn declares “It seems like Tesla was designed for Norway. It was made for this ****.”

Even if you aren’t interested in the test itself, the video is worth watching just for the beautiful scenery.

I tried an interesting challenge: Descend 18 % grade on Stalheimskleiva without using brakes on my Tesla Model X.

Start elevation: 375 m

End elevation: 157 m

Drop: 218 m Potential energy released: 218 m * 2600 kg * 9.81 m/s2 = 5.6 MJ = 1.54 kWh

Energy to drive 2 km very slowly: 120 Wh/km * 2 = 0.24 kWh

Net energy after drive: 1.54 kWh – 0.24 kWh = 1.3 kWh

Energy put into battery: 1 kWh Regen efficiency: 77 %

TESLA MODEL X

Tesla Model X at Supercharger
29 photos
Tesla Model X at a Supercharger Tesla Model X Tesla Model X Tesla Model X (wallpaper 2,560x) Tesla says they know the issues with current Model 3 production, but didn't say that the issue had (as of yet) been resolved. Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X Tesla Model X In White (click for high resolution) Tesla Model X (click for high resolution) As Seen  With Skis Tesla Informs Model X Reservation Holders That It Will Be Opening Up More Configurations Soon, Hopes To Release All By Year's End Tesla Model X (click for high resolution) Tesla Model X Tesla Model X 3rd Row Seats Latching Mechanism Found Not Suitable For Europe Tesla Model X Interior/Belts Tesla Model X Gets 6-Seat Option New Design Studio Pictures Show What The Tesla Model X Can Accomodate Tesla Model X Roofline

Categories: Tesla, Videos

Tags: , , ,

Leave a Reply

29 Comments on "Bjørn Descends 18% Grade In Tesla Model X Without Brakes"

newest oldest most voted

Bjorn clearly states in the video Ampera-E (Bolt) has much stronger regen, and so does the 2018 Leaf…

They have stronger regen at slow speeds. At high speeds im pretty sure the Model X can get back more kW than the Bolt or Leaf.

Have not driven the new leaf yet. But Having driven an S/X several times and owning a Bolt, I can say that the Bolt has stronger regen particularly when using the ‘regen on demand’ steering wheel paddle. But using that paddle might violate the spirit of the self imposed rules of this test 😉

Even without the paddle, on a relatively flat road the Bolt can come to a complete stop without braking. (I don’t believe the S and X can.) But on the downside the Bolt going around those turns at 15+ mph with no braking might lead to some squealing tires begging for traction lol!

2018 Leaf with e-pedal would stop at any point on that slope you let of the accelerator, thats the whole point of true 1 pedal driving that Tesla’s are not capable of.

However, the Leaf’s e-pedal *does* engage friction brakes to fully stop the car. The Bolt (and I’m assuming the i3) can stop the car without friction brakes, though the Bolt can do it much better since the regen is stronger.
Sounds like GM is bring 1 pedal driving to the ’19 Volt too.

I am not sure at what speed the e-pedal engages friction brakes, but my guess is less then 5MPH, The regen in the 2018 leaf is impressive, and I think equal to the Bolt… I drove them in succession a few weeks ago, and came away more impressed with the Leaf then the Bolt for a few reasons, e-pedal being one of them. I really do like the Bolt’s paddle though, thats pretty clever. Bolt is clearly a better engineered car, but its a bit too expensive, and missing some tech the Leaf has.

Does 2018 Leaf regen so strongly even after driving in hot summer day or very cold winter day? If it does, you’re cooking/freezing the battery and shortening its life. I’d hate to drive down some mountain road on Leaf these days (another heat advisory in SoCal).

As for Bolt too expensive, Bolt at $22K to $25K post subsidy on sale these days is perfectly reasonable pricing compared to other cars of similar features and performance (GTI, Focus ST, etc).

Leaf with 0-60 in 8 seconds (ever slower than SparkEV!) should be about $15K to $18K (Mazda 3, Civic, etc). But considering lack of TMS that one must wonder constantly about killing the battery in summer and winter (strong regen without TMS also kills battery in cold), it should be worth far less. To me, Leaf at anything over $0 is way too expensive.

The Bolt can regen over 70kWh.

Here’s a very informative video about Bolt regen power.

https://www.youtube.com/watch?v=VoJgmrI1naU

I’ve seen as high as 60 kWh on my Pacifica. Would love to see more given its mass, but I understand you can only zap a 16 kW battery so hard without damaging it.

Actually up to 70 kWh, but not over.

What is max regen for a Tesla?

I have not seen the Tesla’s I have driven over 50kw Regen, but then again have not tested specifically trying for high regen rates.

Looking at posts on the Tesla Motors Club, it seems the answer is “slightly more than 60 kW.” Someone posted a picture of a gauge readout, but it looks like a logarithmic display, so hard to judge the exact amount. Instead of me guessing, look for yourself:

https://teslamotorsclub.com/tmc/posts/884978/

And please note regenerative braking power is measured in kW, not kWh. #SI-UnitsNazi

I do not have any data at high speed, so would just be speculating.

“At high speeds im pretty sure the Model X can get back more kW than the Bolt or Leaf.”

You base this on what? Bolt is capable of 70kW, SparkEV is 60 kW for 2866lb car, and both can regen this power highway speeds. This is possible due to best thermal management among any EV. To have similar regen, Tesla X would need 90kW (or more) regen due to heavier weight. Most I see on youtube top out about 50 kW.

Now if you’re talking about old Leaf after driving in hot summer day, yeah, they could have very little regen. But that isn’t the case with new Leaf (or is it?)

Nope. For all their EV technological superiority, Tesla’s cars have always been weak on regen. If you press the brake pedal, Tesla cars engage friction brakes built for gasmobiles; no regen involved. The only regen in a Tesla car comes from letting up on the gas pedal. In most cases, you cannot do full “one pedal driving” with a Tesla car. You can slow the car by setting regen to max and fully letting up on the gas pedal, but if you want to actually stop a Tesla car, you have to use the brakes unless you’re going up an incline.

Regen is even weaker in rear-wheel-drive Tesla cars, since most braking power comes from front wheels in cars with disc brakes. (Pretty much all modern 4-wheeled cars, or at least the ones made in the USA, Japan, the EU, and S. Korea.) But perhaps the MX that Bjørn drives is AWD (All-Wheel Drive)?

He should have done it with the car in reverse. I love descending hills in my S in reverse. It allows you to inversely control the regenerative braking, by applying more pressure on the “go” pedal.

This is one the biggest practical benefits of electric vehicles for heavier trucks. People who often tow large trailers with pickup trucks can expect a brake job every 15-20K miles (or less if you have a Nissan Titan 😉
Hopefully, when we finally get electric pickup trucks, they’ll have “tow/haul” regen mode. Would also be good to have a regen upgrade for the trailer with a charge cord back into the truck.

I am not sure what kind of trucks you have been driving, but my GMC Denali 2500HD tows our 18K loaded equipment trailer at least a few times a month, and has over150K miles and never had new brakes, they are still well over 50%. I have an older Silverado 2500 company truck that has 340K miles and had brake pads once at 285K miles, because they were squeaking, but they still had substantial pad left.

I guess I am not the only one…. http://www.duramaxforum.com/forum/maintenance/919018-brakes-last-forever.html

Yeah, he made this up. Our 2500 and 3500 series GM products have HUGE brakes– last at least 150-200K miles.

Wrong. At least for GM trucks we regularly run 150K miles plus on 2500 and 3500 trucks– these both have huge brakes.

Actually most HD diesel trucks come with exhaust brakes which actually have a very similar feel to heavy regen in an EV. When I tow my 14,000 lb fifth wheel down a 6% mountain pass, I never have to touch the brake and frequently have to press the accelerator just to keep from slowing down too much.

The only problem I have with Tesla is their cars can’t be brought to a complete stop without using the brake pedal. I much prefer the “one-pedal” driving experience of the Bolt.

I’m curious if Bolt is using regen to bring the car to a complete stop. At very low speed, it’s harder to regen and it must be using some power to come to a complete stop. The display shows it’s regen even at low speed, I don’t fully trust it.

You could apply reverse torque on the motor. Obviously you would actually use energy to do so but at least the brakes wouldn’t create fine particles.

isn’t 218 m over 2,000m only a 11% average grade? Or maybe the 18% is the “steepest” section of that road.

Everyday, I leave my work place at the top of hill and drop about 434 feet over the distance of about 1.1 miles. My Volt can come almost to a complete stop near the traffic light at the bottom of the hill. I generate about 0.5kWh over the trip without using any energy.

Just be sure you don’t start out with a 100% charge. Or even a 90% charge. REGEN is best with a lower charge.

It you are at full charge with a Bolt, the regen is mostly ineffective. Best to use the hilltop reserve function.