fuel additive


Top Post Dawg
Mar 23, 2011
COLORADO (SE of Denver)
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Welcome to the forums.
Prepare your thick skin for this thread.

hello, does anyone know how diesel additive affect the soot/ash levels in the DPF?
Do a search.
Educated guess here, none of them! The ash content is produced by burning oil, not fuel (for the most part).
Lots of threads with this argument.
Search "Ash"+"oil" in this section.
I'll say it every time and most people disagree some how. Additives are a waste of $ and usually are "snake oils" that dont actually do anythjng usefull other than anti gelling and sulfur additives for older cars pumps.
Another popcorn thread for sure.

Why do you feel you need it?


Veteran Member
Oct 1, 2009
Toledo, WA
2010 jetta
there are a few additives out there that specifically state that its safe for the emissions systems on the newer cars. but finding fact based evidence of what your asking will be very hard.

I do use an additive every tank (optilube XPD) just for the piece of mind of adding lubrication for the HPFP. Has it helped?? I will never know. Has it hurt my DPF?? I will never know. I am turning 200,000 miles next month and have had no problems with HPFP or DPF. My DPF is probably cracked, my tailpipe has been sooty for 3 years now.

asking about additives is like asking which tire is best, or using anti-sieze on lugnuts. everyone will have an opinion based on personal preference and what they have experienced. Good luck of finding an actual answer to your question.


Veteran Member
Oct 25, 2014
2014 OZ Cruze CTD & 2010 JSW 6MT & 2017 GMC Canyon CCLB ATX 2.8 Duramax
Ash is permanent and can only be removed by cleaning of the DPF. Yes there are some organo-metallic additives which enhance combustion and improve DPF function by reducing soot generation and lowering burn-off temps. These are called catalysts, an example would be something similar to ferrocene or MMT. Lubrizol, Afton among others have developed patented catalysts. I believe Mobil Synergy Diesel Efficient has a catalyst additive in the formula.

These additives may be part of a balanced formula which will have other properties like enhanced lubricity, raise cetane, remove deposits, de-emulsify water, protect against corrosion, etc...

There are also phony additives which likely do nothing other then separate you from hard earned cash. These snake oil additives give dubious results and use deceptive or vague advertising, I'd avoid anything claiming to be a "Secret".

My experience comes from using an MMT based additive. It works, and works very well at reducing soot generation. The others I have not tried.

Common Catalyst additives:

FBC - Iron based https://betterdiesel.com/
Amalgamated TDR-FL - MMT Based https://www.amalgamatedinc.com/store/tdr-fl
FPC-1 - ?? Iron based (Ferrocene) ?? - https://www.fpc1.com/