Fuel Additives?

Diesel Car magazine used to regularly recommend a product from Miller Oils that everyone swore reduced smoking and was generally A Good Thing, especially before an emissions test.

I have a big can of it that I slop into our cars occasionally when I remember. I can?t honestly say I?ve noticed any difference. It?s smelly stuff and hard to avoid getting a few drops on the outside of the bottle which then stinks the car up if you keep it in the car.

Tim

it is more important to buy good quality fuel, I have never seen evidence that additives do anything noticeable, while vehicles that run on branded (esso, shell etc.) fuel last longer and are cleaner inside and at the tailpipe (thinking of a customer's 400k miles lexus LS that runs as clean and silently as when new, always filled with shell petrol and shell helix oil)

Hazardous ingredients: COMPONENT 72161 30-50% [N] R51/53; [-] R66; [-] R67 ? COMPONENT 72089 50-75% CAS: 27247-96-7 [Xn] R20/21

Contains: Component 72161 - Branched chain alkaryl hydrocarbon CAS No.

68784-56-5(10-20%) and petroleum heavy aromatic solvent naphtha CAS No. 64742-94-5 (30-50%). Component 72089 - 2 ethyl hexyl nitrate (>99%).

The latter is indeed supposed to improve the cetane number. So it does indeed contain potentially useful ingredients.

Theo

nce. It?s

The percentages sound interesting:

10-20% and >99%.

I think that means:

The Stuff is composed of 30-50% of A and 50-75% of B. A is composed of 10-20% of A1 and 30-50% of A2 B is composed of >99% of B1

The only bit that doesn't add up is the composition of A, which I suspect is because it contains something else that isn't hazardous so isn't recorded on the MSDS.

Theo

Yes, I agree that seems plausible. So the percentages are per component, and not of the stuff as a whole.

My answer would be if they really do work, why don't premium brand fuel suppliers already add them?

Well, I used to have a Nissan Micra. The tick over was a bit uneven so I took it to my trusted garage. He said something about a blocked injector and poured a bottle of this stuff in. No charge. He also told me to "drive the bloody thing". It was doing 3k miles per year. A week later the tick over was fine.

an italian tune up may have done exactly the same thing :)

Oil companies spend tens of millions on developing the additive packs for their fuels - especially those going into the premium grades (eg. Shell develop in conjuntion with the Ferrari F1 team, whilst the diesel was the Le Mans Series fuel for many years).

My problem with additives is that you really don't know if or how they're going to interact with the additives already added by the fuel companies.

Now, I work in the industry and will always recommend a branded fuel (especially the one used by the Ferrari team!) - but will say this... if you are going to use a supermarket unleaded, Tesco Momentum is the only one I'd touch - because I know exactly where that one comes from. A lot of supermarket fuel is bought on the spot market and you cannot guarantee it'll come from the same source every time. I wouldn't touch a supermarket diesel unless really, really desperate.

Understood.

In this case what does spot price mean? Is it the crude before refining or the product that actually goes in the car? I'm not aware of the final product being shipped in quantity between countries.

Albeit 40(ish) years ago, I shared a house with someone who was responsible for the dispatch and checking of tankers from a south coast refinery. He said that the tankers carrying branded and supermarket filled up from the same bulk tanks.

Final product is shipped, especially to the UK where we don't have the refinery capacity to meet all our needs.

By 'spot market', I mean they'll trade anything from any source, be it bunkered in the UK, still on a vessel or UK refined product. It means you can never guarantee you'll get the same product twice.

Base product may be the same, but the important bit is the additive - and that's the bit which varies between brands. Many sources have a 'common' additive for supermarkets / low end brands - whilst the big 3 of Shell, BP and Esso will have their own specific additives (or even source of base fuel for the Ferrari related retailer)

(Some supermarkets, in trying to cut costs, have rushed the cleaning of tankers, too - leaving residue of silicon based cleaner in the tanks, which completely buggers up common rail diesel injectors)

A reasonable point. I suppose cost could be a reason. A few extra pence per litre could drive (no pun intended) people to cheaper brands.

I remember in the 1960s, when my father had a Ford Popular, he'd ask for '5 gallons and x shots' when filling up (no self service in those days). The shots were squirts of something (I assume oil like) from a red conical shaped container.

upper cylinder lubricant comes to mind.

Redex was the stuff, an 'upper cylinder lubricant'

Is there a reason why drivers can't add their own additives? The diesel additive mentioned upthread raises the cetane number, allowing fuel to burn faster.

Is there anything actively harmful in the lower grade fuel?

Theo

I'm not aware of any current engine tech. that will adjust for increased Cetane. Octane, yes, as a modern engine will have knock sensors and advance timing until they trigger the knock sensor. But I'm not aware of any diesel equivalent.

Nothing harmful, but there are proven benefits in using the premium grades - with unleaded, the extra cleaning and friction reducers assist with engine longevity, whilst the increased octane can deliver better performance and / or economy (smaller throttle opening for the same performance).

For diesel, the premium grades can (and do) make a significant difference to emission control systems - particularly the DPF. Many taxi drivers swear by the premium diesels... particularly the one developed in conjunction with the Le Mans endurance teams!

Local taxi firm run all the diesel cars on the cheapest supermarket fuel until they start to slightly miss at small throttle openings then switch to premium fuel until it clears then back to the cheap stuff

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