[Flasshhhh]

Nice explanation! I was quite confused between Diesel and Petrol for my next car. But now I am certain that Diesel is not for me(although I will miss the mileage). Reading Team BHPians advices are a great help.

[ashis89]

Originally Posted by gauravdgr8

Why would this be. Any specific reason identified? Isn't premium diesel supposed to be much cleaner?

Good question. Premium diesels aren't cleaner fuel but have additives in regular fuel which are supposed to help clean the combustion chamber and other areas. I am not an expert here but burning of these additives can block the DPF and hence, not recommended.


This is how HP explains Turbojet diesel:

What is TurboJet?

TurboJet is a new generation diesel, which contains multi-functional diesel additives to keep your vehicle healthier-resulting in better performance, more mileage, easier acceleration and lower emissions.

Even Shell V Power is laced with similar 'cleaners'.

https://www.shell.in/motorists/shell...er-diesel.html


A grab from the Kia user manual which mentions avoiding use of such additives

[Cresterk]

Originally Posted by Aviator_guy

I'm wondering if we take into account all these DPF related issues and diesel lost due to regen cycles, not to mention about the inconvenience when these things happen out of the blue, whether going for Diesel car makes sense anymore specially for urban driving (and occasional highway runs) conditions ?

I think people should take into account all these factors while evaluating petrol vs diesel options.

It really does not. I finally gave up on diesel after searching all through 2021-2022 and bought a hybrid. As much as I like the low end torque and lazily getting up to highway speeds, it's just not worth it anymore.

[sbm]

Originally Posted by audioholic

The key element to soot burn off or passive regeneration is high exhaust gas temperature over an extended amount of time. This is achieved only under high load and high speed conditions. However with a large engine like the 2.4 or 2.8 Toyotas, the engine is hardly under load and EGT never rises to the levels that soot can burn off. .....manual regeneration or DPF light blinking. Regen kicks in 200-250kms or so and does it's job in ten minutes be it on the highway or in bumper to bumper traffic.

You echo my thoughts here, but I have a query regarding my XUV700 diesel manual. Up to 17000 km on the odo, the car didn't throw any regen warnings, even though I used to drive a significant amount of time in the city and on short trips. But after a software update, I started getting these warnings every 150–200 km. These warnings go away if I drive for 10–15 minutes at 2k rpm, and I can tell from the slight fluctuations in power delivery around a certain rpm that the regen is going on. I now recall that these fluctuations in engine power used to occur earlier, also when the car was not giving any warnings, and I suppose the system was completing active regen in multiple attempts.

But my dilemma is that earlier I wasn't getting any warnings, and the car was performing regen even when driven in the city, and now it's giving warnings, but regen is getting completed after a few minutes of continuous driving. One factor to consider is that none of my trips are longer than 10 kilometers these days, and most of them are only 3–4 kilometers. Although there is no traffic, there are many quick-start stops. I got the car checked at the service center, and they said that it's normal as you are driving short trips. Should I attribute the frequent warnings to the fact that they might have lowered the warning parameter to prevent multiple aborted regenerations, or is there actually something wrong with the car?

There is no change in the performance of the car, and many other users have also reported similar behavior after the said software update, just these frequent regen warnings.

[torquehead]

Hi BHPians,

I had been driving my 2017 S-Cross Alpha Diesel until 2022 when I decided to part with it since my car-usage pattern changed during and post-covid days. I had trouble adding more miles to it, owing to nature of my work. Those were the good-old BS-IV days and I had no issues with its performance or worry of BS-VI DPF, DEF issues in my 5 years of ownership.

Since my monthly running dropped significantly(less than 200-300km), I took a grand i10 Asta Petrol, that has served me well over the last 1.5 years.

Things changed recently and now I am considering alternatives which can also deliver some occasional bursts of fun during family-trips on highways. Owing to DCT/DSG woes, I am considering diesel options of Creta, Seltos & XUV700(tried others as well, but couldn't consider them for reasons not relevant to this thread).

Here is my dilemma:
- I am a sedate driver who likes to enjoy the low and mid-range torque and hence stay on the lower side of RPMs(this does not imply lugging).
- My monthly city running may still be low(max 200-300 kms)
- My highway running will be much higher on each trip. To put things into perspective, this might stretch to about 3000 kms on a single trip. Usually, single trip will be more than entire month's city run.
- Annually, the car would clock about 10000 kms or less, of which 70-80% will comprise of highway or outstation trips.
- There could be several days when the car is not used at all.
- There could be occasional months, when there is little city-running(200 kms) but no highway-runs at all.


Here are some of my concerns:
- If the driving-pattern above should be a cause of concern for DPF health.
- As long as the car runs more on highways and less in city, is there a minimum number of kms the car should be clocking monthly, in order to avoid this issue?
- Is manual-regen harmful for the engine in the longer-run?
- How many litres of fuel does it consume, each time manual-regen is performed?

Thanks,

[Mortis]

You haven't mentioned your budget. If you want to skip DPF hassles and still get higher mileage vs petrol then consider the Toyota or Maruti Hybrid.

[Bibendum90949]

Originally Posted by torquehead

Owing to DCT/DSG woes, I am considering diesel options of Creta, Seltos & XUV700(tried others as well, but couldn't consider them for reasons not relevant to this thread).

Here is my dilemma:
- I am a sedate driver who likes to enjoy the low and mid-range torque and hence stay on the lower side of RPMs(this does not imply lugging).
- There could be several days when the car is not used at all.
- There could be occasional months, when there is little city-running(200 kms) but no highway-runs at all.
Here are some of my concerns:
- If the driving-pattern above should be a cause of concern for DPF health.

I can share my experience with DPF equipped vehicles after having owned the very first BS6 diesel vehicle in the country, that's the Seltos. I owned it for 3 years and 30k kms. I had researched on the subject quite well before taking the plunge to buy a BS6 diesel. I had made out that my driving and usage pattern won't give any DPF tantrums as such. The car was largely used on highways but there were times it logged 250-300 kms a month in the city without seeing an highway in the same period. In such instances, it was inevitable to face DPF chokes.

IIRC, I had DPF clogging issues twice or thrice. When I say clogging, I mean it called for a highway run to trigger the passive regeneration. And with prolonged city usage I was expecting to get into such a situation. So an Italian tune up ensued and all was well.

The only time I ended up with an active regeneration was during one of the scheduled services. Since I had a long journey lined up two days later, and the car was used a bit in the city limits, I requested the technician to run the diagnostics to see the soot level. It was on the brink of getting into a situation of it demanding a highway drive. Since I didn't want such an error at the start of a long journey, I proactively asked them to do the active regen. They initiated that and it was all done in 20 mins or so.

In short, expect DPF clogging if you use your cars in city traffic for extended periods. It's more about the number of hours one clocks in city than the kms. If it's crawling traffic day in day out, it's just a matter of time before DPF acts up. But if you are in a city but still can drive at 30-40 kmph for larger part of your commute, you can quite easily keep the DPF tantrums at bay. All you need to do is to drive in lower gears every now and then. Keep it on the boil a bit.

For instance, If a 30 kmph can be done without lugging the engine in gear 3, do the same in gear 2 - not every single time but more often. If you follow this religiously, DPF at least in 1.5 litre engines isn't a problem at all. By the way, I had the diesel AT Seltos. Hence I used to move it to manual mode and shift gears manually every now and then during city runs. Even on highway runs i use manual mode extensively for engine braking. But if it's bigger CC diesels like Crysta, Fortuner et al this practice can get counter productive as shared by audioholic in his post above. Do read that.

One of the cars in my current garage is the new Thar D AT. It's a BS6 engine too, the 2.2 litre m Hawk. I largely follow the same practices shared above, with Thar too. I've done 30k kms in one year and faced DPF clogging(means it called for a highway run for passive regen) only twice. Both times, it was expected owing to extended city usage prior to that.

Once, I even pushed the city usage further by driving normally, without any conscious effort of keeping higher rpm s in lower gears, just to see how many kms can I clock in the city without any highway run. And it lasted 220 kms or so. But then, Thar is tuned for performance and it stays in higher rpm s even when you're driving at 30-40 kmph too. So all the dynamics can vary depending on the vehicle's engine and tuning characteristics.

One can buy a diesel BS6 without worrying about DPF, if they know what they're getting into. It's not much of a hassle, in my experience. Good luck on your purchase.

I'm also attaching my older posts on this subject, if it helps in your decision-making.

Originally Posted by Bibendum90949

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

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

https://www.team-bhp.com/forum/techn...ml#post4890468 (BS6 Diesel Car owners - Your experience with DPF / SCR / AdBlue here)

[torquehead]

Originally Posted by Mortis

You haven't mentioned your budget. If you want to skip DPF hassles and still get higher mileage vs petrol then consider the Toyota or Maruti Hybrid.

Well, mileage is not my cocern here at all. I want a diesel-engine for its better low-end and mid-range torque without high-revving.

Honestly I don't have a real budget in mind but anything less than 35 lacs that can offer me a good value(decent space, power, features) without too many hassles for the next 7 years will do. If that comes from a 25 lacs car(Creta/Seltos), I am fine with it. If it requires me to shell a bit more for the peace of mind and stretch to XUV 700 that costs upwards of 30 lacs, I can consider it too.

Maruti is a strict-NO for me and Toyota too as they are in the same boat. Reasons? I don't want to start another debate here

Originally Posted by Bibendum90949

I can share my experience with DPF equipped vehicles after having owned the very first BS6 diesel vehicle in the country, that's the Seltos. I owned it for 3 years and 30k kms. I had researched on the subject quite well before taking the plunge to buy a BS6 diesel. I had made out that my driving and usage pattern won't give any DPF tantrums as such.

One can buy a diesel BS6 without worrying about DPF, if they know what they're getting into. It's not much of a hassle, in my experience. Good luck on your purchase.

Thanks, this does help.

From all the opinions(need to depend on those as the manufacturers don't bother educating their customers) gathered thus far, I could comprehend that,
- Fewer the bumper-to-bumper traffic runs, longer it would take for the DPF-issue to occur.
- Passive-regeneration will take care of it in most cases.
- An occasional visit to ASC for forced-regeneration, though a slim-probability event is not ruled-out when passive and manual regeneration fail to do the needful.

Wondering if I missed anything here..

Thanks,

[krishnakumar]

Originally Posted by torquehead

From all the opinions(need to depend on those as the manufacturers don't bother educating their customers) gathered thus far, I could comprehend that,
- Fewer the bumper-to-bumper traffic runs, longer it would take for the DPF-issue to occur.
- Passive-regeneration will take care of it in most cases.

Bibendum covered all the major points on avoiding DPF issues and completely concur, having owned a BS6 Diesel for the last 2.5years. In that period, I too have had 3 cases of DPF alert coming with one requiring an active regen which I did myself (thank god for Mahindra offering this as an option that can be done by self). And all of those instances involved city-heavy drive periods with little to no highway runs.

I’ll add one more thing on best practices. Avoid short city runs, even if there is no traffic. If your run cannot ensure good engine temperature and time for soot to clear, that too will cause DPF to clog up.

Therefore, avoid regular short city runs (like dropping in to the nearby supermarket) even if there is no traffic. As a practice, see what distance or time it takes for the engine to come up to operating temperature (the stable point in the temp gauge) and that becomes your benchmark to hit if it all you do city drives. The best practices on those city drives have been covered by Bibendum.

As long as you have a highway run (even a good 30mins) every 2-3 weeks, you should have no concerns on DPF if your city usage is diligently followed. It’s not for everyone, but if it meets your usecase, then nothing to worry.

Just to reiterate, it’s not as if you cannot do them at all. Minimize the number of times you do such short city runs. That’s all.

[padmrajravi]

Originally Posted by krishnakumar

I’ll add one more thing on best practices. Avoid short city runs, even if there is no traffic. If your run cannot ensure good engine temperature and time for soot to clear, that too will cause DPF to clog up.

True that. This is really the only thing that owners need to worry about. The DPF software logic and the hardware is matured by now. If you let the system do its job, everything will be fine. The catch is that for the system to do its job, it needs to reach operating temperature and that happens only in drives with atleast half an hour of duration. From my experience, the RPM or the speed of your vehicle does not matter, it is the duration of the drive that matters. You need to give engine enough time to reach operating temperature and stay there for some time. There is no need for high speed drives. Count the number of times where your engine's continuous usage is less than half an hour. Each of those instances gets you one step closer to a DPF issue. A few instances of this happening is not a problem, but if most of your drives ar like this, you will end up in a DPF problem even with that odd high way run. That said, the instances of DPF issues being reported in the forum has decreased a lot over the last year.

[Aviator_guy]

My gosh ! After reading the do's and don't, the bs6 diesel engine looks like a spoilt, moody baby who needs constant pampering! It is so opposite to the traditional diesel engine which was abuse friendly, fill n forget type. I wonder whether customers recognize the effort and painstaking maintenance new era diesel engines would need. Not to forget that it is a dying breed due to environmental concerns and hybrid/EV onslaught.

Hope people take rational decision considering all these factors in mind !

[ashis89]

Originally Posted by torquehead

Here are some of my concerns:
- If the driving-pattern above should be a cause of concern for DPF health.
- As long as the car runs more on highways and less in city, is there a minimum number of kms the car should be clocking monthly, in order to avoid this issue?
- Is manual-regen harmful for the engine in the longer-run?
- How many litres of fuel does it consume, each time manual-regen is performed?

Thanks,

I have done 500-600 kms in Bangalore City between my highway trips and without any issue. It all depends on the kind of traffic you are driving through daily. Driving with a slightly heavy foot at times helps.

2-3 weeks of no use multiple times and that has not been a concern as well.

For BS6 diesel, always use plain diesel and avoid premium ones with additives.

Originally Posted by Aviator_guy

My gosh ! After reading the do's and don't, the bs6 diesel engine looks like a spoilt, moody baby who needs constant pampering!

All this for a slightly lower running cost vs. a turbo petrol. If running cost is not a concern then a turbo petrol should be more tension free.

[ruskinash]

Originally Posted by Aviator_guy

My gosh ! After reading the do's and don't, the bs6 diesel engine looks like a spoilt, moody baby who needs constant pampering! It is so opposite to the traditional diesel engine which was abuse friendly, fill n forget type. I wonder whether customers recognize the effort and painstaking maintenance new era diesel engines would need. Not to forget that it is a dying breed due to environmental concerns and hybrid/EV onslaught.

Hope people take rational decision considering all these factors in mind !

I decided to buy a variant with a petrol engine instead of a diesel engine this time because of the issues surrounding DPF/DEF.
Although I miss the diesel's torque, I now have fewer things to worry about. Furthermore, as the price difference between petrol and diesel continues to decrease, it's becoming less practical to own a diesel-powered vehicle.

[Revvatron]

I bought my first diesel car in 2022 which is Hyundai I20( sportz). Till now never faced any dpf issues. I read about it in tbhp forum and was keeping an eye on rpm's only during the initial few months. But now I barely keep dpf in mind while driving. Most of my driving is in highways, there are instances where my car is stationary for couple of weeks. But whenever it is on highways it is always a lengthy drive like 500 kms atleast.
I only use two wheeler for city travels unless it is too long to travel or I have multiple people with me. So definitely not concerned about dpf. Infact my next will be Diesel again. Because you just have fill it and forget it. No matter how hard you drive it , you will still get more than decent mileage.

[torquehead]

Originally Posted by ashis89

All this for a slightly lower running cost vs. a turbo petrol. If running cost is not a concern then a turbo petrol should be more tension free.

That's exactly how I started and I was not too keen on Diesel hearing about the BS Vi woes. Sadly, all decent turbocharged-petrol options either come with a DCT or a DSG gearbox, both of which have their own set of problems.

Thanks,