[audioholic]

Guys, it has been a few months since the BS6 rollout and after the many discussions we have had over possible implications in the Indian market scene, effect of various emission systems like DPF/SCR/LNT etc I believe we have passed those times and now we do have many owners including me who have gone ahead and purchased these cars due to various reasons. Barring all these discussions, lets keep this thread to discuss the on-field experiences with these engines. There are other threads where members have debated whether these systems are suitable, how they fare in our conditions, economics of a BS6 diesel and what not. But in this thread, lets limit the scope to the following points:

• How is the exhaust after-treatment handled in your car? What system(s) is used.
• In your driving experience with the car, has the car required any manual regen? Or has it just been like driving any other car?
• How frequent has the regen process happened and whether manual intervention was required?
• If you have an SCR system in the car which requires AdBlue, what is the AdBlue consumption like?
• Has there been any issues so far?

Let us not get to the trivial topics of:

• Overall ownership of the car
• Why buying a diesel BS6 car is not a good idea
• Anything other than not mentioned in the above points

Giving my own account, in my BS6 Innova AT diesel, it comes with a DPF+SCR setup. We have done 2k kms till date and until now, apart from improperly topping up Adblue during first service, which was a mistake of the dealership, there have been not much of issues.

The car comes with a manual switch to trigger DPF regeneration. However so far we have not yet had a need to use it. When using it only within city traffic, the engine tries to do a mini regeneration every 200-300 kms which lasts for five minutes if only idling. During this, the idle speed increases to 1200RPM and the exhaust is noticeably hot. However, once this process also happened after a spirited highway drive followed by 1hr of driving in traffic.

In the coming days, I will be curious to see the actual consumption of Adblue. According to Toyota, the 12L Adblue tank must last close to 10k kms, but lets see what the realistic figures are. Hence, I believe there would be others here on the forum who might have higher running, and might share a better idea on this thread.

Look forward to your replies. This thread can be a good reference over the next few months/years for those who are worried about how BS6 diesels will fare.

[Bibendum90949]

I drive a Seltos diesel and has clocked 16k kms so far and it uses a DPF unit to keep emissions under control. I had engine warning light once owing to choked DPF. The car had to be taken for an active DPF regeneration at the service centre. On another occasion during a general check up before a long journey, the oxygen sensor was found to be clogged at 80% and hence required the regeneration. As everyone knows, Seltos was launched with a BS6 engine in Aug'19 and has been running on BS4 diesel till we started to get BS6 fuel in April this year. Both the aforesaid instances are during the BS4 times. The higher sulphur content in BS 4 must have amplified the DPF choking frequency.

My first brush with DPF issue and it's experiences are shared in detail in the below post.

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

But i've only run 3k kms since using BS6 fuel and have not faced any DPF warnings since then. At the same time, my friend's Seltos had the warning once within 400 kms and his car had run only in city limits during that period and he was on BS6. Each time he had to pay a visit to service centre. He also had three more instances of DPF choking, all during BS 4 and 90% city commute. In fact it's not just the kms covered in city limits that should count, instead the number of hours one spends in city limits. To log 400 kms in city, one could take 35-40 hours or even more depending on the traffic, means more quantity of fuel is burned without passive regeneration.

From my conversations with many other diesel Seltos owners in whats app groups, it's safe to conclude the DPF warnings now are not as frequent as in BS4. And unless the car is running only in city limits, one should be able to run at least 10 k without any DPF warnings and by then car reaches the scheduled service interval and service centre can do a DPF regen then.

The passive regeneration gets triggered when car is run at higher rpm's for a longer period. It means such rpm' s are never achieved in city limits and the regeneration will never take place and will eventually clog the DPF , and hence one will be faced with DPF clogs if car is used largely for city commutes even during BS6 regime.

There is just another observation. I don't have any technical details to provide. In the same stretch of roads in city limits at similar traffic and driving conditions, the car returns different FE at different times, that is at least 15-20% less. This I suspect happens when the system is trying for a passive regeneration and hence more fuel is fed into engine and owing to weak RPMs, it gets aborted. Would like to hear from fellow members on this. I can't think of any other reasons for such inconsistencies in city FE for same road and driving conditions.

Yes an onboard system like in the Innova Crysta that can trigger DPF active regeneration would be really handy in such situations, even if it means pulling over the car to carry out the same. If not that, at least a warning light in the instrument cluster that shows the level of DPF/oxygen sensor clog that would make us aware of the impending situation beforehand and take the remedial measures than getting caught unawares during a journey or when one's about to commence one.

So far apart from these warnings, I've not faced any other issues so far. But I'm not sure whether running my car for at least 7000 kms on BS4 fuel had any adverse effects on DPF, only time will tell. Kia claimed that they had done extensive testing on BS4 fuel before launching Seltos. I gather that driving long enough with a clogged DPF is detrimental to its life besides loss of power and can even create back pressure to the engine that can cause engine damage or even soot getting to the oil sump through the combustion chamber.

Another thread in which DPF issues were discussed
https://www.team-bhp.com/forum/techn...te-filter.html (FAQs about DPF (Diesel Particulate Filter))

[GTO]

While some initial teething issues will be there (as Seltos owners found out), this will largely become a fill-it-shut-it-forget-it kind of exercise. Sure, AdBlue requires some additional effort such as topping up at services & a bump up in cost, but all of that is worth it when we consider the drastically reduced emissions.

Back to the topic, someone in my family has a BS6 Benz and lots of highway running (even during lockdown). The experience has been a breeze with no owner intervention at all. I only recommend him to park a spare bottle of AdBlue in the boot, just in case.

[RSR]

When diesel particulate filters were first introduced globally, owners faced a ton of problems with DPF clogging and regeneration issues. International sites are filled with complaints about the first models from almost all carmakers that came equipped with a DPF.

I believe the first DPF-equipped models had design issues as there was no previous experience to draw upon. However, manufacturers have used the experience and tons of data from the initial models and made design changes that made DPFs much better and way less prone to issues on their subsequent models.

We in India moved to DPFs rather late compared to most First World markets. So I guess we are getting the improved designs and owners won't have that much to complain about in the long run.

[ajmat]

I guess that's why VW/Skoda are watching and waiting re: usage patterns, owner experience etc before relaunching diesel variants. Why give diesel a bad name!

[ashis89]

Another Seltos diesel owner, I haven't had any encounter with DPF issues so far *touchwood*!

I have covered 13k kms so far. Of this, between Nov '19 to Mar '20, I covered 7.5k kms on BS4 fuel (assuming BS6 fuel was not available in Hyderabad and Bangalore). That said, my city usage was always mixed with some highway runs where I could maintain steady speeds for 30-40 kms at least. At a stretch, I would have done +/-300 kms in the city before I headed out to the highway.

During my visit to the service center for the first and second service, I had reported of few owners getting the engine check light. The service center attributed it to the BS4 fuel causing issue.

After checking with few owners on the FB groups, WA groups as well as service centers, I found a common link among these owners - premium fuel. Almost all these users had been filling premium diesel from different outlets - HP, Shell, IOC. On the other hand, I have refueled from bunks of every available brand in the country but always insist on normal diesel. It seems the BS6 engines don't like the premium diesels. Off-late, number of owners reporting this CEL issue is far and few between.

KIA ECU Update

In December 2019, KIA had also released an ECU update, supposedly to help the engine cope with BS4 fuel. However, post the update, I found the mid range to have mellowed down to an even more linear power delivery but with a better low end and a bump in FE too. Owners who got the ECU update, still reported the CEL light and clogged filters but the frequency of the issue was reduced, meaning they covered longer distances before the DPF got clogged.

MID Display

Especially in cars where manual regen options are not available, I would like to have a gauge which shows how clogged the DPF is or a pre-emptive warning well before it is fully clogged. I had posted this earlier too. In case such an option is available through an OBD port too, it will be welcome option for us owners!

Originally Posted by ashis89

With BS6 diesels and DPFs going wonky, I would like a reading of how clogged the DPF is and a warning at 80% mark to regenerate it!

Testing standards

Another point worth looking into - what were the test conditions for the BS6 diesel cars while they were road tested in our country? Were they driven extensively in the city for thousands of KMs and in heavy traffic conditions? Were they run with the fuel available in our fuel bunks across the country?

None of the OEMs have disclosed any pre-conditions for diesel engines (such as these engines need high speed runs?). No warnings as to how a DPF might get clogged. They have given the instructions of how to resolve when a DPF is clogged.

Originally Posted by ashis89

• What’s the minimum number of KMs the vehicles are driven? How many different drivers are involved in this testing? Is the emission testing done while the vehicles are running on actual roads (to prevent VW like scandals)?

• Are the cars tested using normal fuel available across fuel bunks in our country? In case of KIA seltos, the OEM claims the car was tested extensively with BS4 fuel but users are still facing issue after running the cars on BS4 fuel. On the other hand, a friend of mine told me that another OEM tested its BS6 powered cars using BS6 fuel sourced specially and made available to the test fleet.

[Bibendum90949]

Originally Posted by ashis89

Another Seltos diesel owner, I haven't had any encounter with DPF issues so far *touchwood*!
I have covered 13k kms so far. Of this, between Nov '19 to Mar '20, I covered 7.5k kms on BS4 fuel (assuming BS6 fuel was not available in Hyderabad and Bangalore).

Though 01 Apr'20 was the deadline for all OMC's to be on BS6, few of them like Reliance, BPCL etc started receiving BS6 stocks as early as Dec'19 in few cities. This was confirmed by a friend who's a Reliance bunk owner. Most Seltos owners who were regularly refuelling from Reliance never got the DPF/MIL warning. This may have played a role in your car not getting the warning. I was filling Shell non premium diesel for 90% of my 12k during the BS4 period and faced with DPF issue twice.

[sgm]

I drive a BS6 C220D with an SCR and DPF setup. My usage is mostly within the city and the occasional long drives have completely dried up due to Covid-19. C-class comes with a 15L AdBlue tank and it is around half-way mark now after covering 7k KMs. One full tank is supposed to last for 10k at least for city usage and based on the MID information, I think it will easily last more than 12k KMs for pure urban driving.

For DPF regeneration, there is no manual option and I'm not sure when and what is triggering it but I assume that it has been happening at the right time. The only indication that makes me believe that regen happens is, when Auto Start-Stop is enabled, at signals, the car doesn't turn OFF automatically but the engine continues to run normally but I haven't noticed any change in the RPM levels. The auto start-stop indicator turns Yellow in this case when Auto Hold is used at signals. I’m not sure if this happens due to regen or because the engine has to be running to maintain the AC temperature

Another observation is that, I feel that the car is a bit more quieter after switching to BS6 fuel, though I don't have any real data. I had taken the dB readings sometime back using my phone but the phone is changed now, so comparing the readings using the same app on two different phones may not be the right way to conclude on this.

[zalaps]

Mahindra DIY has released nice video on refilling of diesel exhaust fluid.

https://m.youtube.com/watch?feature=...&v=gA7Pkj9JuKw

[SansGT]

Originally Posted by zalaps

Mahindra DIY has released nice video on refilling of diesel exhaust fluid.

Strange! Doesn't the Marazzo come with the 1.5L engine? My understanding (supported by lot of threads in this forum) was that the DPF + SCR combo comes only in engines above 2L, and those below 2L have gone for the DPF+LNT setup.
Does the XUV300 with the same engine come with SCR or is it just a LNT?

[mankuthimma]

I have Seltos Diesel AT and driven around 2k kms now, entirely in BS6 era post lockdown. So it is still early to say. But so far DPF has been a non-issue. Havent really noticed any perceptible indication that DPF being regenerated or may be it could have happened transparently. The drives are always enjoyable especially on the highways with the punchy and smooth diesel engine.

Have filled diesel from Shell, Essar and nowadays, using IOC COCO station regularly. Usage is mostly in highways and quite less in city owing to the current situation.

My understanding is that DPF cycle kicks in every 400-600km range when a higher rpm and certain engine temperature is reached.
I like sedate driving style. On an average, my city runs are usually in 40-60 kmph and highway rides between 80-100 kmph speeds. With AT, gear changes happen at around 2k rpm and on a highway, 100 kmph is reached by the time needle hits 2k rpm. Holding onto this 100 kmph/2k rpm for a long time itself is a challenge on our highways. Also, havent see engine temp needle cross the 50% mark. In the Italian tune up videos, the cars are driven at really high rpm! Not sure, whether my driving style + AT is conducive for DPF regeneration ?

[guyfrmblr]

Yet another Seltos Diesel owner. I have driven around 5100 km until now and haven't faced any problems. I bought the car in the BS6 era (May 2020) and have been filling regular Diesel only at Shell pumps (which is closest to my home). The only time I used a non-Shell pump was an Indian Oil pump on the day of delivery. 80% of my drives were on highways.

[Bibendum90949]

From the XUV 300 MID. It would've been more useful if there's a forewarning than a warning.

[Stribog]

Originally Posted by ashis89

Another
After checking with few owners on the FB groups, WA groups as well as service centers, I found a common link among these owners - premium fuel. Almost all these users had been filling premium diesel from different outlets - HP, Shell, IOC. On the other hand, I have refueled from bunks of every available brand in the country but always insist on normal diesel. It seems the BS6 engines don't like the premium diesels. Off-late, number of owners reporting this CEL issue is far and few between.

Add me to the sample list. Drove on bs4 fuel in my Seltos from Nov - Feb, no worries with dpf.

Then passed a shell bunk once, filled in premium diesel and dpf lit up like a Xmas tree.

Stopped using it (after a visit to the SVC centre) and all normal.

[SansGT]

Originally Posted by Bibendum90949

From the XUV 300 MID. It would've been more useful if there's a forewarning than a warning.

Saw these pictures on Facebook. Now, what is the actual scenario over here has to be understood from the owner's manual. I can see a lot of warnings.

• It can just be the warning where one needs to drive the car for some kms at high speeds to enable active regeneration. I believe the same to be the case as the owner did not mention about power loss (limp mode).
• Even if you ignore the MID, there is a small DPF warning light at the bottom and the green REGEN light at the left. One really needs to understand what each of these means. And that's where my concern is. None of the manufacturers have clearly spelt out what DPF is and how to maintain the same in the long run. Given that it is such a critical part, they should try to bring more awareness instead of just a small paragraph in the owner's manual. There is a clear lacking on the side of the buyers too as the majority don't even care to go through the owner's manual of the new car. Even in this case, the owner was unaware of what the warning meant.