Is BS-6 diesel causing harm to BS-4 engines?

It’s not just ultra low sulphur diesel that is in play. The government has quietly started selling B5 (5% biodiesel blend) as normal diesel, at least here in Delhi NCR.

BHPian toamitraj recently shared this with other enthusiasts.

I recently saw this reel

Here the user highlights that the Diesel currently sold is BS6 compliant so less in Sulphur and any old cars should use a mix of 3ML 2T oil per litre, I need your guidance.

I drive a 2012 Innova Type 3 - It's been an amazing ride for me but yes there has been a lot of tappet noise and impact to mileage.

Here's what BHPian Shreyans_Jain had to say on the matter:

It’s not just ultra low sulphur diesel that is in play. The government has quietly started selling B5 (5% biodiesel blend) as normal diesel, at least here in Delhi NCR. It’s a double whammy for old diesel cars. Injectors and fuel pumps are going to give trouble.

Here's what BHPian AMG_Power had to say on the matter:

Check out this Team-BHP thread.

It is correct that reduction in sulphur will lead to reduction in lubrication. However, oil companies add proprietary lubricants in BS6 diesel to make up for reduced lubrication in low sulphur diesel.

Here's what BHPian MileCruncher had to say on the matter:

I drive a 2018 BS4 VW 2.0L TDI done about 89K Kms. Bought the car used in March 2022 with 58K on clock. Serviced at VW with regularity and have never faced any issue with knocking.

I have been seeing these reels. Wondering why the OEMs have not made any advisory.

Here's what BHPian Karan561 had to say on the matter:

I have been using Xtra Green Diesel (IOCL) which is supposed to be a new age clean diesel with higher cetane value on my 2nd Gen 2016 Fortuner 4x4 M/T & I am extremely satisfied with the overall positive results in terms of performance, refinement & overall feel good factor.

Never trust reels, only trust long format videos with proper explanations.

All the best

Here's what BHPian biju1971 had to say on the matter:

I just checked the fuel specifications of the fuel being supplied for our marine diesel engines. The exact name is low sulfur high flash high speed diesel and i think is similar to the diesel for our cars. I can see the sulfur content is .005%. The manual says sulfur content < 1%. The fuel pumps and fuel valves have very less clearance and the sulfur provides lubrication. Lower sulfur can cause stickiness in the moving parts. I am not exactly sure but i do feel the fuel leak off from the fuel pumps and injectors has increased in our marine diesel engines.The other way it affects is that the lubricating oil TBN(total base number) is designed for a particular sulfur content( to counteract the sulfuric acid produced during combustion). The lower sulfur content and the initially high TBN may lead to deposits in the combustion chamber(this is my surmise).

I own a Ciaz ZDI and have seen the mileage in my car has reduced, although nothing much has changed in the noise and pickup front. I spoke to our fuel supplier to know how they are counteracting the reduced sulfur content.He told me that no additives are required because they maintain the percentage of FAME(fatty acid methyl ester) and that helps to maintain lubrication of fuel pumps. I dont understand that because i am not a chemical engineer. This conversation is regarding the fuel supplied for marine diesel engines. I believe this could be applicable fot the diesel supplied in our pumps also.
I also bought a can of Liqui Moly diesel cleaner after going through this thread, but i dont think it is required on a regular basis.

Read BHPian comments for more insights and information.