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Old 20th August 2020, 18:10   #1
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by GTO View Post
Voted for the Kia Seltos. The Diesel + AT combination is superb - that engine & AT are a match made in heaven. As good as the car itself! While the Petrol DCT is also fast & competent, I'll go with the diesel due to its inherently superior reliability over a dual-clutch gearbox, higher FE and the fact that both are similarly priced. Even otherwise, I am really attracted to the Seltos' styling + interior + features + handling.
What are your thoughts on the DPF issues if driving is primarily in city?

Would you suggest the DCT over the diesel then?

Last edited by GTO : 22nd August 2020 at 08:14. Reason: Copied our posts to a new thread as so many cars now have a DPF
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Old 22nd August 2020, 08:10   #2
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by sv97 View Post
What are your thoughts on the DPF issues if driving is primarily in city?
If your DPF is getting blocked primarily because of short-commute city driving, it only means one thing = GET A LIFE (sorry, no offence meant ).

- Go for a long drive on the highway .

- If no time for highway, go for a long drive in the city @ higher speeds. E.g. in Mumbai, it could be the Sea Link & Freeway. In Bangalore, it could be the airport road.

- Give the car an Italian tune-up from time to time (sample video below).

After all, as BHPians, we live to drive! So go out, and drive for the pleasure of it. Tell the wife that "my DPF needs it".

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Old 22nd August 2020, 10:11   #3
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Default Re: Diesel DPF clogging due to short city commutes

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Originally Posted by Bibendum90949 View Post
This is just what I've been doing last couple of months, 80% of my drives during the period were just for the sake of driving and for 'Italian tune-up' ! Yes my car spots the Tbhp LTD sticker, need to do justice to it . Needless to say it has a DPF too.

All idling and no 'drive' makes you and your car a dull boy. I feel, If you don't keep your engine in good spirits, it would turn lethargic too, like us humans .
It's not just the DPF that needs to be purged, it's also the LNT. Unlike the bigger SUV's the Seltos uses a LNT+DPF vs SCR+DPF.

In the SCR, you use Urea fluid to purge the system whereas in LNT system you have to do the italian tune up driving once in a while.

The Seltos gets a LNT (Lean NOx trap) which also needs italian tune up and regeneration. If you do not use it in the highways and use short commutes it will run a burn cycle with rich fuel mixture to try and clean the LNT+SCR system.

Last edited by Vid6639 : 22nd August 2020 at 10:36.
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Old 22nd August 2020, 10:19   #4
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by GTO View Post
If your DPF is getting blocked primarily because of short-commute city driving
This is probably a stupid question, but I am struggling to understand the logic here.
Short drives = less intake to filter
This should mean lesser blockage no?
Then how come higher blockage? Sounds counter intuitive.

Can someone please explain?
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Old 22nd August 2020, 10:24   #5
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by RedTerrano View Post
This is probably a stupid question, but I am struggling to understand the logic here.
Short drives = less intake to filter
This should mean lesser blockage no?
Then how come higher blockage? Sounds counter intuitive.

Can someone please explain?
Short drives = lower rpm and lower rpm means less pressure to flow through the restrictive filter leading to soot accumulation at the entry side of the filter.

The longer drive on highway is usually at higher rpm's and gets cleaner intake air, hence the higher exhaust pressure literally blasts or purges through the filtration system. It's like a pressure wash vs a normal water hose wash.
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Old 22nd August 2020, 10:27   #6
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Quote:
Originally Posted by RedTerrano View Post
This is probably a stupid question, but I am struggling to understand the logic here.
Short drives = less intake to filter
This should mean lesser blockage no?
Then how come higher blockage? Sounds counter intuitive.

Can someone please explain?
Even though I am no expert on this but due to the lower emission requirements of BS-VI the soot particles have to trapped in the filter so as to prevent higher emissions being emitted by the car.

The soot particles to be burned off require the engine to be run at higher temperatures which can only happen when the car runs at higher speeds.

So, when going for a short city drive this doesn't happen as the speeds achieved generally are lower and the engine does not run at high temperatures required to burn off the soot particles leading to blockage.

Hope this answers some of your questions.

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Originally Posted by Vid6639 View Post
Short drives = lower rpm and lower rpm means less pressure to flow through the restrictive filter leading to soot accumulation at the entry side of the filter.

The longer drive on highway is usually at higher rpm's and gets cleaner intake air, hence the higher exhaust pressure literally blasts or purges through the filtration system.
This might seem a bit stupid but if only RPM's alone could do the trick then if we restrict the car in a particular gear would the soot be burned off even in city conditions?

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Last edited by Sheel : 22nd August 2020 at 10:41. Reason: Mod note attached.
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Old 22nd August 2020, 10:35   #7
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Default Re: Diesel DPF clogging due to short city commutes

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Originally Posted by Vid6639 View Post
Short drives = lower rpm and lower rpm means less pressure to flow through the restrictive filter leading to soot accumulation at the entry side of the filter.

The longer drive on highway is usually at higher rpm's and gets cleaner intake air, hence the higher exhaust pressure literally blasts or purges through the filtration system. It's like a pressure wash vs a normal water hose wash.
Thank you. Makes sense now.


Quote:
Originally Posted by sv97 View Post
This might seem a bit stupid but if only RPM's alone could do the trick then if we restrict the car in a particular gear would the soot be burned off even in city conditions?
My thoughts exactly.
After reading @Vid6639's reply above I was also wondering the same. Thanks to Chinese Virus, longer commutes might not be possible. Would cranking up the RPMs while the car is parked in neutral help?
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Old 22nd August 2020, 10:36   #8
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by sv97 View Post
This might seem a bit stupid but if only RPM's alone could do the trick then if we restrict the car in a particular gear would the soot be burned off even in city conditions?
Yes even that would work. Infact a long drive is only an excuse. Theoretically you can do it standing still and revving in neutral for a few mins.

The Innova has an SCR system that tells the driver when it needs cleaning. To clean just park the car, press the button on the dash and the car runs the high rpm regeneration burn cycle for 15-20mins on it's own.

The only drawback to this is that you are wasting fuel and not moving and also revving when parked does cause higher temperatures which is not something any engine likes. A highway drive means the car is sucking in cool air, the engine is optimal with good air flow all around and you get a clean diesel emission system as well.

Last edited by Vid6639 : 22nd August 2020 at 10:41.
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Old 22nd August 2020, 10:41   #9
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Default Re: Diesel DPF clogging due to short city commutes

Attaching the relevant section from Harrier BS6 owners manual for reference -

Diesel DPF clogging due to short city commutes-screenshot_20200822103316_drive.jpg

Diesel DPF clogging due to short city commutes-screenshot_20200822103408_drive.jpg

Diesel DPF clogging due to short city commutes-screenshot_20200822103448_drive.jpg

TATA Motors recommends about 20 mins of running above 2000rpm to regenerate the DPF if the warning lamp comes on.

Also, do note - this isn't a major malfunction indicator, so nothing to panic - unlike some of the other warning lamps. Modern diesel owners will be seeing this one quite a few times in their ownership. That said - can't be ignored either as the car can't be used for long without regeneration.

Last edited by CrAzY dRiVeR : 22nd August 2020 at 10:52.
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Old 22nd August 2020, 10:50   #10
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Default Re: Diesel DPF clogging due to short city commutes

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Originally Posted by Vid6639 View Post
It's not just the DPF that needs to be purged, it's also the LNT. Unlike the bigger SUV's the Sletos uses a LNT+DPF vs SCR+DPF.

In the SCR, you use Urea fluid to purge the system whereas in LNT system you have to do the italian tune up driving once in a while.

The Seltos gets a LNT (Lean NOx trap) which also needs italian tune up and regeneration. If you do not use it in the highways and use short commutes it will run a burn cycle with rich fuel mixture to try and clean the LNT+SCR system.
Thanks Vid for a separate thread on this. We've one more thread on DPF FAQ' s. Not sure if both can be merged

The below pointer is from the seltos manual. DPF warning light is reported by many Seltos owners, more so in the times of BS 4 fuel. And as you said, most of them were running in city for extended periods. Unlike other cars, Seltos doesn't have an onboard active regen mechanism that manually triggers the process(like the one we've in Innova Crysta). Hence driving it at higher RPM 's once a while for extended periods is the only way for active DPF regeneration to take place in cars like Seltos, Creta.

Just sharing my related posts on this for the benefit of followers of this thread.

https://www.team-bhp.com/forum/offic...ml#post4771540 (Kia Seltos : Official Review)

https://www.team-bhp.com/forum/techn...ml#post4851226 (FAQs about DPF (Diesel Particulate Filter))
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Old 22nd August 2020, 11:00   #11
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by Vid6639 View Post
Yes even that would work. Infact a long drive is only an excuse. Theoretically you can do it standing still and revving in neutral for a few mins.

The Innova has an SCR system that tells the driver when it needs cleaning. To clean just park the car, press the button on the dash and the car runs the high rpm regeneration burn cycle for 15-20mins on it's own.
Thank you for the information Vid6639. The SCR system certainly sounds strange. How many times in a month do we have to run the burn cycle? I canít imagine the judgemental eyes Iíll get from my neighbours when I do this . The car is parked and I rev the engine for 15-20 minutes. Either theyíll think Iím insane or showing off my new car. Itís hard to explain the burn cycle to my apartment folks and itís hard for them to comprehend. However, is this a compulsory thing? Canít we burn the soot in a Toyota just by driving it in higher rpms like the Kia diesels? Since most of us take our Innova/Fortuner out on the highway frequently, or is hitting the button on the dash a routine that Toyota owners should get used to?

I was planning on getting the Kia Sonet to replace our Baleno and decided on the diesel AT. My work place is exactly 1km away from my house and it takes me less than five minutes to reach. The engine wonít even reach half of the optimum temperature before I reach. My father and I go to work and come back home 3-4 times a day. The engine never really heats up. Our annual usage is 15k kms. I should probably go for the petrol, but that comes with the DCT . This will be our first automatic and I didnít want it to be a dual clutch. Thank you!

Cheers!
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Old 22nd August 2020, 11:23   #12
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Default Re: Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others

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Originally Posted by VRJ View Post
However, is this a compulsory thing? Canít we burn the soot in a Toyota just by driving it in higher rpms like the Kia diesels? Since most of us take our Innova/Fortuner out on the highway frequently, or is hitting the button on the dash a routine that Toyota owners should get used to?
The manual regeneration using the button is only needed when you don't do high rpm's and no highway drives. When the system gets clogged due to low rpm city commuting it then tells you to do a regen manually as it was unable to do it on it's own. So in a way the Toyota system is better as you can do it manually when it tells you to.

The Tata system will just put a warning light on dash and tell you to drive at high rpm's since it has no button.


Quote:
I was planning on getting the Kia Sonet to replace our Baleno and decided on the diesel AT. My work place is exactly 1km away from my house and it takes me less than five minutes to reach. The engine wonít even reach half of the optimum temperature before I reach. My father and I go to work and come back home 3-4 times a day. The engine never really heats up. Our annual usage is 15k kms. I should probably go for the petrol, but that comes with the DCT . This will be our first automatic and I didnít want it to be a dual clutch. Thank you!
Diesel in general is not preferred for short commutes. A diesel gives lower FE when cold and does not like frequent short trips. To top it off with the BS6 system this is further aggravated with short commutes.

If you don't have too much traffic, do look at the DCT. Either option has it's pitfalls so it's not an easy pick.

Cheers!
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Old 22nd August 2020, 12:14   #13
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Default Re: Diesel DPF clogging due to short city commutes

Ideally, all manufacturers should put an Innova style DPF regen button on the car, that will maintain the engine at the required RPM for the required time in neutral when stationary. This should be the standard backup option in case regular usage isn’t enough for the burning off. A spare tire kind of solution for the DPF, which saves us from an expensive visit to the service center.

Whenever the system detects a dangerously choked DPF, a message should display on the screen asking to user to park the car and press the DFP regen button. 20 mins later, the car is good to go!

Last edited by Shreyans_Jain : 22nd August 2020 at 12:16.
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Old 22nd August 2020, 12:37   #14
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Default Re: Diesel DPF clogging due to short city commutes

A long time ago, the owner of the FNG where I service my Scorpio had told me to ensure that the temp gauge needle reaches optimum operating temperature, before indulging in any spirited driving at high rpms. Not sure if this is needed in newer cars prior to DPF cleaning, but just thought of mentioning it as a word of caution.

Last edited by comfortablynumb : 22nd August 2020 at 12:40.
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Old 22nd August 2020, 13:12   #15
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Default Re: Diesel DPF clogging due to short city commutes

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Originally Posted by comfortablynumb View Post
A long time ago, the owner of the FNG where I service my Scorpio had told me to ensure that the temp gauge needle reaches optimum operating temperature, before indulging in any spirited driving at high rpms. Not sure if this is needed in newer cars prior to DPF cleaning, but just thought of mentioning it as a word of caution.
Revving excessively on cold engine is bad for engine health in long term. Also after engines reaching optimal temperature, they perform better. Otherwise they are very sluggish. Especially old diesel vehicles or the ones which are not daily driven. cross posting my post from other thread regarding the same Link (Tata Harrier Automatic vs Hyundai Creta vs Kia Seltos vs others)
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