A trip to your local motor factors, or favourite internet motoring forum, will reveal a bewildering array of Diesel Fuel Additives, many ranging in price from a few £££’s to eye watering figures equivalent to taking the other half away for a romantic weekend.
Even more confusing is that virtually each and everyone of those additives will make veiled promises to you on the label or the glossy leaflets, and whether its making your engine run smoother, reducing your diesel fuel consumption or cleaning your injectors or even helping to maintain your DPF, there will be something to make you want to part with your hard earned cash in return for a bottle of this marvelous secret elixer!.
Whilst many manufacturers will try and hint in their marketing that there is some secret formula in their diesel additive or that they have discovered or invented some miracle chemical not accessible in other diesel additives, in the most part this is just clever marketing – a play on words which just appeals to consumer curiosity and human nature.
In reality, for most of the off the shelf Diesel Additives, the main or active ingredients are no secret at all, in fact they have been around for generations and first appeared in the very first fuel additives that our parents were probably using.
These two main diesel additive ingredients are basically
2-EHN (2 Ethyl Hexyl Nitrate)
and…..wait for it……..
Kerosene, (or Paraffin to us Brits). albeit in some ultra refined form
Super – Duper, Secret additive which can wipe 100,000 miles wear off your engine = 0% content. Sorry, but there is nothing in any additive which can effectively give you a new car or undo years of fair wear and tear!.
But don’t give up!, some diesel additives can help with some problems, and some can be very effective at problem prevention and improving your MPG – read on
Even the most basic diesel additives can boost your diesel fuel cetane ratings to give you a smoother cold start and perhaps give you a few extra mpg (Although more than 3 or 4 mpg is wishful thinking), and that is exactly what the 2-EHN Content does, it boosts the Cetane level of the diesel fuel, by as much as 4 points.
Next the Kerosene content acts as a cleaner, although there is much debate and much skepticism about how much use the Kerosene content is as a fuel system cleaner, in the very small dosing amounts which come with the majority of diesel additives. I, personally remain to be convinced about the benefits of a few ml of Kerosene is when added to a 60 litre tank of fuel, so i’m not going to preach about or promote the Kerosene content in diesel additives, even though suffice to say they do make up a high percentage of what is in the bottle (draw your own conclusions).
So, when it comes to off the shelf diesel additives, by far the best ingredient in your Diesel Fuel additive of choice, is the 2-EHN content, because this is by far the most effective chemical which will be of the most benefit, in fact it was one of the first chemicals added commercially in the first ‘Premium’ diesel fuels. However, how effective will be, will depend entirely on the percentage of 2-EHN in your additive, and you can often find this written in the MSDS datasheet, generally buried somewhere on the manufacturers website.
Unfortunately, in a lot of cases, the 2-EHN content is low, perhaps too low to be of any benefit when diluted with Kerosene or other petroleum derived additive. My advice, is to just buy the 2-EHN directly in its purest form and add it directly to your fuel tank in the advised doses. This, by far, will be more cost effective than adding it in diluted form, mixed with Kerosene in the form of many other additives, and best of all, pure 2-EHN additive doesn’t cost any more than the miracle additives!.
Pure 2-EHN, boost the Cetane Rating of your diesel fuel which improves the response of the Engine, assists with cold starts and may improve your MPG
Similar to the cost of regular additives, but in a higher concentration, 2-EHN is by far the most effective additive on a budget!
So, that is the Diesel Cetane taken care of, but what about cleaning the Fuel System and helping to keep your injectors clean?. Kerosene is a very good cleaner, but illegal to add in large quantities, and is of little, if any benefit when added as a few ml in additive form.
P.E.A!!, PEA! what about the P.E.A??
Ok, now the interesting bit. There is a chemical which can be added to Diesel Additives which research has found to be of immense benefit. True it won’t make you a better lover and I would never describe it as a miracle but its likely to be the best additive that money can buy in relation to what you can add to your fuel tank in relation to yielding results and more importantly cleaning your diesel fuel system and that chemical is referred to as polyetheramines or PEA for short. In addition, some P.E.A Diesel additives also contain a further Fuel Detergent called polyisobutylene succinic anhydride (P.I.B.S.A to its Friends) which give yet another layer of cleaning action to your Diesel Fuel system.
I won’t go into the Science here, but a quick internet search will bring up many years of research into the Benefits of PEA based additives when used in Diesel Fuel, and it is a Chemical which is both manufactured and used by many well respected brand names, including some Premium Diesel Fuels. In fact PEA based additives are the additives which you often buy from the Main Dealer, and rebranded with their labels, and include AUDI, BMW, DAIMLER, PORSCHE, VOLVO CARS & VW
I’ve tried a lot of PEA based additives in my own Diesel Cars (with and without DPF’s) and have had very positive results from them all, to the point where I now prefer them over the 2-EHN / Kerosene based additives which fill the shelves of the Motor Factors.
I have listed the PEA based Diesel Additives which I recommend from my own experience below, and all have produced benefits when used in both of my cars. Why not try them all to see what works best in your car?.
BASF Keropur D. BASF is one of the leading global manufacturers of polyetheramines, so it stands to reason that their own brand Diesel Additive will have high concentrations of PEA. BASF also manufacture own brand fuel additives for most of the major car manufacturers including BMW, VW, Volvo & Porsche.
This is the additive which I now use routinely, adding a tub every 2000 miles.
BASF Keropur D (Mini OEM). We already know from their product website that BASF Manufacture Keropur for many main car dealers and I am convinced that the own brand BMW & MINI Diesel Additive is simply a rebrand of Keropur-D, and buying it this way online also cheaper than buying the original BASF product. But both options are included so you can try and choose for yourself!.
Archoil are a well respected manufacturer of Diesel Additives, and their AR6900-MAX is a premium PEA based additive, which is not only chock full of polyetheramines but also has a healthy additional dose of pibsa / pibsi fuel detergents to help remove fuel gum and varnish residue
Techron D is manufactured by Chevron / Texaco, and was the first ever PEA based diesel additive which I came across several years ago. For me, it produced reasonable results, far more than conventional additives, but may lack the additional cleaning ‘punch’ of the additives above.
That said, its still a good all rounder and worth a trial.
If you live in a City or have frequent problems with your DPF blocking then you may have to resort to using a Diesel Additive which is formulated to actually reduce the soot emissions from your Engine.
Less soot, means fewer particles to block your DPF, meaning longer periods between the requirement for DPF Regeneration.
Originally formulated for City Taxi’s the CDTI Platinum Plus is an expensive, but effective means to enable City Driving with a DPF Car.
Please leave your comments and feedback below in relation to trying these additives, and also any suggestions for other Diesel Fuel Additives.