Using Additives in BMW Diesel Cars

[shaftdrive]

I have owned my BMW 335D coupe (E92) from new (since 2007) it has only done 40K miles and I am very happy with it except the MPG have decreased from 30 to 25 mpg over the years. My mechanic has suggested that I use a diesel additive in my car and has recommended Archoil AR6400 Pro Fuel System & Injector Cleaner. The fuel cap clearly says no additives. I am not sure, but the mechanic says it is harmless. Has anyone ever used it and is it OK, will it clean my injectors and is it likely to help or harm my car. Thanks

Edited by shaftdrive on Monday 18th November 20:41

[Locknut]

My cynical view of all additives is that they are harmless and therefore useless. If an additive is safe to put in the tank and safe for the fuel pump and all the seals etc., how can it be aggressive enough to shift varnish and carbon from the toughest, hottest and most pressurised parts of the system.

Sorry if that's not what you wanted to hear, but I suppose the direct answer to your question must be that you'll be OK putting in the additive.

[MikeGoodwin]

Run it on V Power or whatever they call it these days.

[Ruxpin]

I have put a few doses of Millers Power Sport 4 (or its new equivalent Diesel Power Ecomax)through my 335d and can't say i noticed any difference - ie no improvement in economy, no more power and no smoother.

Interestingly, previously i ran a Fabia VRS (vag pd130 tdi engine) on Millers Power Sport 4 for over 50k miles - it returned 4% more mpg and always felt smoother. (supermarket diesel and BP ultimate performed exactly the same...)

It just doesn't seem to do much to the bmw. Be interesting to hear peoples experiences of other cleaner type products.

One thing that might be worth checking is the operating temperature of your 335d. The water temp in my 56 plate car was only getting to 77C. Changing both thermostats has improved economy by 2-3mpg and should also prolong the dpf life.

[shaftdrive]

Thanks for your very helpful replies. I am a newcomer to PistonHeads and really impressed with the response from members. Thanks again, I don't think I shall be using any additives in my 335D. On another note I was reading in the BMW forum people asking for the best place to buy OEM parts at reasonable price, I have always found bmwpartsonline.co.uk very helpful and reasonable.

[Tea Pot One]

I have a tin of BG44 (? I think - the diesel one anyway). I have bought it to put in my 330d but have been worried it will do something to the car despite the claims and online reviews ... my car has only done 20K and I run it on BP Ultimate diesel so guess I have probably no use for it yet.

[Defcon5]

I think the Forte potions are the best of the bunch

[stevesingo]

Ruxpin said:

One thing that might be worth checking is the operating temperature of your 335d. The water temp in my 56 plate car was only getting to 77C. Changing both thermostats has improved economy by 2-3mpg and should also prolong the dpf life.

^^^^^^^^
This

[gizlaroc]

I have always run my cars with additives, and when you look at the injectors etc. on them at 100k etc. they are clean as a whistle.

All fuel has additives, the more expensive fuels tend to have more of them, which is why they cost more at the pump.




Regarding your 335d, you checked your 'stats?
When did the consumption drop? We are now on winter diesel at the pumps, that makes a difference.

[redtwin]

gizlaroc said:

I have always run my cars with additives, and when you look at the injectors etc. on them at 100k etc. they are clean as a whistle.

All fuel has additives, the more expensive fuels tend to have more of them, which is why they cost more at the pump.

Which ones do you use?. What benefits do you notice?. I used to run my old 330d on Millers years ago, but can't say I noticed any difference. I have a 535d now and was wondering if there is anything new out there worth trying.

[gizlaroc]

I use Millers most of the time but just found out that someone down the road stocks Forté, so now using that in our older ML270cdi.

I noticed the most difference when I was in Europe and stopped using additives for around 4 tanks, it was considerably noisier and just lost a bit of pep.

Also the other day my wife pulled up in it and I thought there was an issue, got her to pop the bonnet and it sounded really clattery. She then said "Oh, I filled up the other day and didn't say, not put any of that stuff in because it stinks".

I put half a bottle in to the half a tankful left and by the next day it was quieter again, and just felt smoother all round.

If I stop using the stuff I get black smoke out the back under heavy acceleration, that tells me that it can't be doing harm.

Considering it costs me £110 to fill up, another £4 or additives is sod all imho.

[simes43]

Since the introduction of "biodiesel" fuel systems
are gradually being clogged by animal fats and a
bacteria/fungal growth.

Additionally, fuel station owners and haulers have a
constant battle with the percentage of water in their
storage tanks.

Search for fuel polishing, diesel tank cleaning for
more details.

[shaftdrive]

I had a chance to speak with one of the old mechanics at BMW Sytner about fuel additives, and his take on this question was perhaps a little amusing and I would like to share this with my fellow BMW owners. He said that the modern injector systems are so designed that they clean themselves and the very high pressure with which the diesel is injected into the chamber, would make it impossible for any residue or carbon to build-up on them. He felt that in the last thirty years of working on cars and in particular diesel cars, his view is that all these additives are a gimmick designed to fool keen drivers who will fall for anything. He says he has tried on some of us "keen drivers" by telling whoever enquired about them, that he has put in a special additive in the fuel and to report back what they think, and without fail everyone reported a marked improvement in the performance and fuel economy of their car, he said it was like a "placebo" effect and told me to go spend my money on a nice meal.....for what it's worth...

[simes43]

shaftdrive said:

I had a chance to speak with one of the old mechanics at BMW Sytner about fuel additives, and his take on this question was perhaps a little amusing and I would like to share this with my fellow BMW owners. He said that the modern injector systems are so designed that they clean themselves and the very high pressure with which the diesel is injected into the chamber, would make it impossible for any residue or carbon to build-up on them. He felt that in the last thirty years of working on cars and in particular diesel cars, his view is that all these additives are a gimmick designed to fool keen drivers who will fall for anything. He says he has tried on some of us "keen drivers" by telling whoever enquired about them, that he has put in a special additive in the fuel and to report back what they think, and without fail everyone reported a marked improvement in the performance and fuel economy of their car, he said it was like a "placebo" effect and told me to go spend my money on a nice meal.....for what it's worth...

The good quality cleaning additives will only restore the fuel system back to normal when introduced regularly. The injectors are just the last part of the chain.

The problems fuel outlets are experiencing with algae and high levels of moisture are just happening on a smaller scale in all of our cars.

Perhaps you are just driving faster or your dpf filter is on its way out.

[redtwin]

gizlaroc said:

I use Millers most of the time but just found out that someone down the road stocks Forté, so now using that in our older ML270cdi.

I noticed the most difference when I was in Europe and stopped using additives for around 4 tanks, it was considerably noisier and just lost a bit of pep.

Also the other day my wife pulled up in it and I thought there was an issue, got her to pop the bonnet and it sounded really clattery. She then said "Oh, I filled up the other day and didn't say, not put any of that stuff in because it stinks".

I put half a bottle in to the half a tankful left and by the next day it was quieter again, and just felt smoother all round.

If I stop using the stuff I get black smoke out the back under heavy acceleration, that tells me that it can't be doing harm.

Considering it costs me £110 to fill up, another £4 or additives is sod all imho.

Cheers, will have to give it a go for a couple tanks and see what happens.

[gizlaroc]

redtwin said:

Cheers, will have to give it a go for a couple tanks and see what happens.

The other you can use is some 2 stroke oil, low ash and mineral, if it doesn't say synthetic on it, it will be mineral.

Carlube 2 stroke is £2.99 for 500ml at the moment at The Range.

200:1 is the rough mix, so half a botttle to every tank.
This also makes a noticeable difference.

[Ruxpin]

shaftdrive said:

I had a chance to speak with one of the old mechanics at BMW Sytner about fuel additives, and his take on this question was perhaps a little amusing and I would like to share this with my fellow BMW owners. He said that the modern injector systems are so designed that they clean themselves and the very high pressure with which the diesel is injected into the chamber, would make it impossible for any residue or carbon to build-up on them. He felt that in the last thirty years of working on cars and in particular diesel cars, his view is that all these additives are a gimmick designed to fool keen drivers who will fall for anything. He says he has tried on some of us "keen drivers" by telling whoever enquired about them, that he has put in a special additive in the fuel and to report back what they think, and without fail everyone reported a marked improvement in the performance and fuel economy of their car, he said it was like a "placebo" effect and told me to go spend my money on a nice meal.....for what it's worth...

LOL - The "placebo" effect from my fabia vrs (All measured tank to tank)

Facts....

Mileage covered / Type of Fuel / MPG / Cost Saving
21,765miles / BP / 44.73mpg / 0%
61,981miles / BP + Millers Power Sport 4 / 47.33mpg / 5.79% saving

There were some longer journeys with roof box etc in the "BP" figures above but even knocking them out the cost saving was 4-5% when using a standard dose of millers at every fill up.

I have only run the 335d on BP + Millers for 8,370miles but didn't notice any significant changes in economy, noise or performance. However, i have subsequently had various items changed on the car that may affect economy (boost hose, thermostats) so i may give the millers another go as i was very impressed with it in the skoda.

[shaftdrive]

Love to hear how you get on with using it in your 335D.

[redtwin]

gizlaroc said:

The other you can use is some 2 stroke oil, low ash and mineral, if it doesn't say synthetic on it, it will be mineral.

Carlube 2 stroke is £2.99 for 500ml at the moment at The Range.

200:1 is the rough mix, so half a botttle to every tank.
This also makes a noticeable difference.

I have heard about the 2T oil also, may try that first as the Millers I have to hand is what's left of a big 4 litre tin I bought about 6 years ago. I still use it in an old Fiesta with no ill effects but wasn't sure I should stick it in my car.

[wax lyrical]

That's pretty shockingly poor fuel consumption for a diesel! What's the point?? Is that standard for a 335d?

My 335i auto does 33mpg at 80mph on the motorway. Combined about 26mpg with a LOT of driving in heavy traffic. I only use Shell Nitro plus though.