Any way to know when friction brakes are used? - Page 2 - Kia Niro Forum
 5Likes
Reply
 
LinkBack Thread Tools
post #11 of 18 (permalink) Old 03-19-2019, 06:52 PM
Senior Member
 
Join Date: Mar 2017
Location: SW Ohio
Posts: 1,693
Quote:
Originally Posted by Nouseformonkeys View Post
I have nothing else to add, but I do notice when pulling into my driveway or into a parking spot, that the car will stop before I want it to even when I let off the brake. Once it has stopped, the car won’t inch forward until I step on the gas pedal again.

And I also will let off the gas when I see that I have to stop up ahead so that I don’t have to use the brakes prematurely and maybe won’t have to stop completely before traffic starts moving again.
Something wrong here with the car's behavior in that first paragraph. Second paragraph is hypermiling - good job!
Quote:
Originally Posted by padonion View Post
As I said, during downhill for a long period, how do I know that my brake pressure on the pedal relays only regen brake or requires mechanical brake?

Christophe.
Regen is sufficient to maintain speed down the steepest hill. Better practice is to use cruise control to maintain speed rather than the brake pedal though.
padonion likes this.

2018 Kia LX HEV Metal Stream with Advanced Tech
yticolev is online now  
Sponsored Links
Advertisement
 
post #12 of 18 (permalink) Old 03-20-2019, 03:33 PM
Member
 
Join Date: Feb 2019
Posts: 35
Quote:
Originally Posted by yticolev View Post
Something wrong here with the car's behavior in that first paragraph. Second paragraph is hypermiling - good job!

Regen is sufficient to maintain speed down the steepest hill. Better practice is to use cruise control to maintain speed rather than the brake pedal though.
I agree on highways and freeways, but it sounds not safe to be on Cruise control during windy mountain road downhill where you need to negotiate some U-turns

Kia Niro PHEV 2019 Gravity Blue.
padonion is offline  
post #13 of 18 (permalink) Old 03-20-2019, 04:32 PM
Senior Member
 
Join Date: Mar 2017
Location: SW Ohio
Posts: 1,693
Regen is strong! Unless you need to negotiate turns at less than 20 mph, cruise control works great. Otherwise, you can control your speed below 20 mph with the brake pedal using regen. When safe to resume, coast to 20 and resume cruise control. I did just that with perhaps a 20% grade and a 35 mph speed limit over five miles of a one way road. Some of the curves were pretty exciting at 20 mph, but the car handled fine.
padonion likes this.

2018 Kia LX HEV Metal Stream with Advanced Tech
yticolev is online now  
post #14 of 18 (permalink) Old 03-21-2019, 12:19 AM
Senior Member
 
Join Date: Oct 2018
Location: Murrieta, CA
Posts: 324
Quote:
Originally Posted by padonion View Post
Hello,
...
That information is even more useful going downhill in mountain condition. For example, going down from Sequoia Park (30 minutes trip downhill pretty steep), is it safe to gently press the brake pedal all the way down, not saturating the blue regen monitor? Or should I worry about brake temperature and use manual shift for engine brake??

Christophe.
I haven't actually tried this with the Niro, but with other cars I've driven, a crude technique for discovering brake temperature is to pull over, get out of the car, and touch the metal part of the wheels (not the hub caps) to see how warm they are (if you only try this with one wheel, be sure that it's a front wheel since they usually do more of the mechanical braking than the rear wheels do). If you attempt this, you should initially regard the wheels as potentially hot enough to burn your finger: think of how you would test the temperature of a hot iron and maybe moisten your finger and only touch for a fraction of a second at first, until you are certain that the wheel is not burning hot.

When I've done this in the past, the reason for doing it was to discover if I might have one brake that was dragging and heating up more than the others. That's something that's more of a concern once the car gets older though.

In theory, the ideal discovery is that the wheels will feel like ambient temp. In reality though, they might be slightly warmer than ambient, because the rubber tires might also add some heat to the wheel (tires tend to heat up when you are driving by a small amount). If the wheel feels hotter than the rubber tire, then it's likely that you've recently been using your mechanical brakes in addition to your regen brakes, and the surplus heat you feel is an indication of energy lost to heat, rather than being recaptured by regen. If the wheel really does feel burning hot, then in addition to not recovering energy via regen, you might also be overheating your mechanical brakes, which is something that is easy to do on a long mountain downgrade in a conventional car if you rely on just the brake and not the regen or engine braking.
padonion likes this.

2018 Niro PHEV Gravity Blue
deltasmith is online now  
post #15 of 18 (permalink) Old 03-21-2019, 12:51 AM
Member
 
Join Date: Feb 2019
Posts: 35
Quote:
Originally Posted by deltasmith View Post
I haven't actually tried this with the Niro, but with other cars I've driven, a crude technique for discovering brake temperature is to pull over, get out of the car, and touch the metal part of the wheels (not the hub caps) to see how warm they are (if you only try this with one wheel, be sure that it's a front wheel since they usually do more of the mechanical braking than the rear wheels do). If you attempt this, you should initially regard the wheels as potentially hot enough to burn your finger: think of how you would test the temperature of a hot iron and maybe moisten your finger and only touch for a fraction of a second at first, until you are certain that the wheel is not burning hot.

When I've done this in the past, the reason for doing it was to discover if I might have one brake that was dragging and heating up more than the others. That's something that's more of a concern once the car gets older though.

In theory, the ideal discovery is that the wheels will feel like ambient temp. In reality though, they might be slightly warmer than ambient, because the rubber tires might also add some heat to the wheel (tires tend to heat up when you are driving by a small amount). If the wheel feels hotter than the rubber tire, then it's likely that you've recently been using your mechanical brakes in addition to your regen brakes, and the surplus heat you feel is an indication of energy lost to heat, rather than being recaptured by regen. If the wheel really does feel burning hot, then in addition to not recovering energy via regen, you might also be overheating your mechanical brakes, which is something that is easy to do on a long mountain downgrade in a conventional car if you rely on just the brake and not the regen or engine braking.
Thank you for the advice deltasmith. That will be my next experiment I will let you know how it goes!
(But this is why I said that a dashboard indicator would be welcome! )

Christophe.

Kia Niro PHEV 2019 Gravity Blue.
padonion is offline  
post #16 of 18 (permalink) Old 03-21-2019, 09:39 AM
Senior Member
 
Join Date: Mar 2017
Location: SW Ohio
Posts: 1,693
Here is a youtube video of just such a heat test on an Ioniq forum (same exact drivetrain as a Niro).
https://www.ioniqforum.com/forum/7-h...e-braking.html
padonion likes this.

2018 Kia LX HEV Metal Stream with Advanced Tech
yticolev is online now  
post #17 of 18 (permalink) Old 07-18-2019, 10:51 PM
Junior Member
 
Join Date: Jan 2019
Posts: 3
I find it interesting that we must ask when friction brakes are being used. It speaks well for Kia to have such a seamless transference from regen to friction brakes that it is not detectable.
Actually in my car 2018 (Touring) I can't tell when it go from ICE to Hybrid mode either except for looking at real time gas mileage.
Go Kia.

2018 Kia Niro Touring, 2003 VW Jetta TDI
69 XKE 2+2, 65 Mustang Convertible
30 Model A 4 door, 29 Model A Coupe
Bearing1 is offline  
post #18 of 18 (permalink) Old 07-19-2019, 12:46 PM
Senior Member
 
Join Date: Apr 2018
Location: Southern MD
Posts: 288
Garage
Quote:
Originally Posted by Bearing1 View Post
I find it interesting that we must ask when friction brakes are being used. It speaks well for Kia to have such a seamless transference from regen to friction brakes that it is not detectable.
Actually in my car 2018 (Touring) I can't tell when it go from ICE to Hybrid mode either except for looking at real time gas mileage.
Go Kia.
If I'm paying attention I can feel a very slight vibration in the gas pedal when the ICE kicks on but that's about it. That's the benefit of the hybrid-starter-generator vs a conventional geared starter. Being belt driven the HSG is super smooth and quiet. Compared to a rental Audi I had in Italy that had the engine start/stop feature with a conventional starter. That was obnoxious especially at stop lights.

Jim
Southern Maryland
jmurphEV is online now  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Brakes - rear rotor rust Wacio Kia Niro: Likes And Dislikes 13 05-12-2019 06:49 PM
Just bought a new Niro with Tech, regenerative brakes, floor mats Odysseus Kia Niro Owners Registry And Check In Area 4 05-02-2017 10:50 AM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome