I was researching fuel additives for my 2017 2.0TDI 190hp as it seems to be running rough at the moment.

It is due for an oil rinse and service but I was wondering if an additive may help smooth out the engine running a bit more.

I have used Redex previously but that was mainly because this is wha they had in Costco, this time I thought I would ask the forum for people’s recommendations and experiences using these fuel additives to improve engine running

Do you mean an Engine Oil Flush when you say 'Rinse'? Just change the oil when hot. Unless the car is new to you and you do not know the Oil & Filter change history. As to Additives, just go fill up the tank with Premium Diesel rather than standard Derv.

I used Millers when I had my old Fabia Mk1 ASZ engine (1.9pd). I wasn’t overly convinced except when I ran out and after it had washed through the tank and started to empty, it became really troublesome when cold starting. Would stall if I didn’t keep the revs away from idle for the first few minutes.

I did it deliberately again after a few months and was definitely repeated.

But I don’t really understand why it’s needed and I don’t think it’s the solution to something; I think it’s compensation.

Hi,

I recommend reading the user's manual. As Far As I Remember, Fuel Additives are prohibited by VAG.

Regarding oil additives, how many miles on the clock of your Superb?

If it's already above 100000, I fear a pre-oil change additive may be worse than a plain oil change. Indeed, if it has too much detergent properties, it could loosen a whole bunch of residue that could stick where it shouldn't and thus clog some holes/hoses/pipes, and then preventing the normal oil flow with many damages as a consequence...

If you really want to have an idea of how dirty it is. Maybe just remove the oil pan and clean it with white spirit. Then just pay attention to the oil pan seal. I don't now if it's a real seal with a P/N or if the oil pan is sealed using a gasket sealant.

Yes VW say not to use additives. Then there are VW / Audi branded additives and these are sold by VW Group dealers and offered by VW Group / Skoda technicians / Service Desk staff at services.

Edited 16 March16 Mar by Evolution13

Ha. Classic

I've used many fuel additives: Bardhal BDC, ProTec, Castrol diesel additive, Archoil 6900 and Oilsyn Power DNA, and even 2T ashless oil in my old pump duse diesel :D .

In my head, Archoi and Oilsyn seems to quite the engine and make the DPF regenerations less often, but again this is in my head.. 🤓

I've also had good results with Archoil 6400 on a car with blocked DPF due to too many short journeys. It seems to increase the exhaust temperature and actually work in such cases, but I wouldn't use it if there are no DPF issues.

Need to get it scanned to figure out what is happening

Instead of additives maybe just try using HVO. EvoUltra from a Gulf filling station if you are near one or passing near one.

I looked into this years ago when I worked night shifts and had countless hours on my hands. Came to the conclusion that Millers Diesel Eco Max or whatever it is called wouldn't hurt, and could well help. Found it was largely the same thing that fuel stations add to their standard fuel to make it their premium version, just that it works out miles cheaper to do it yourself.

So yeah, I bought a huge can of the stuff, and added it to all the diesel cars I had from then onwards. No longer own one but gave the leftovers to my dad who uses it in his Seat.

@petertr Yes, I did the same but with Archoil, Millers wasn't available at the moment - I bought 5L can and refill a small bottle before or after I go to the gas station.

Premium diesel is good, but with these fuel prices, it's just not an option. Adding this stuff makes the engine less noisy and reduces the DPF regens, or at least I think it does :D

I did a bit of looking in to this using Google's AI mode. Where I got to was:

Rotate between one tank full with Millers Ecomax to three tanks full with Dipetane with a "clean" tank in between to clear out the additives. Giving:

1. Tank full with Millers

2. Tank full with no additive

3. Tank full with Dipetane

4. Tank full with Dipetane

5. Tank full with Dipetane

6. Tank full with no additive

Then back to 1.

The idea being Millers does "cleaning" while Dipetane gives a cleaner burn and less carbon build up. Both are supposed to help increase MPG as well over just diesel.