Are diesel additives worth it?

Are diesel additives worth it?

Author
Discussion

SimonTheSailor

Original Poster:

12,617 posts

229 months

Sunday 6th January 2019
quotequote all
Have my first diesel, last owner put some additive in it every so often.

Never bothered with petrol additives before as I think they are boll*cks and unproven.

Is it the same with diesel additives ?

(This is for cleanliness/mpg rather than performance)

lost in espace

6,164 posts

208 months

Sunday 6th January 2019
quotequote all
I buy dipetane from ebay, increases exhaust temps a bit to keep the turbo clean and a little more mpg. Most additives have this as their main ingredents, Millers etc.

Deep Thought

35,847 posts

198 months

Sunday 6th January 2019
quotequote all
I used to use Millers when i'd a diesel. Loads of additives in it, not just dipetane.

https://www.amazon.co.uk/EcoMax-Millers-Oils-Diese...


LarsG

991 posts

76 months

Sunday 6th January 2019
quotequote all
No point, never used additives in any diesel car I've owned and they all got to around 150,000 miles before I sold them. Diesel has plenty of additives in it already.

Additives are just like Snake Oil.

normalbloke

7,462 posts

220 months

Sunday 6th January 2019
quotequote all
Superchargers,turbochargers,lpg fumigation, intercoolers, yes, to varying degrees. Snake oils in a bottle, not so much...

MYOB

4,794 posts

139 months

Sunday 6th January 2019
quotequote all
No need. It's already in the fuel.

Welshbeef

49,633 posts

199 months

Sunday 6th January 2019
quotequote all
I always use the Millers Additative normally two or three tanks before the MOt is due.

On my F10 535d it makes zero impact to spot - there is none ever. However on the pre DOPF SMax it’s a different case it makes a notable difference to the soot.

I tend to also use a lot more nitro diesel or whatever it’s called. In winter starts much easier plus it’s also much quieter than regular diesel. The other thing is it does Male the car more eager to rev - placebo you may say, I’m a tight person and I wouldn’t wasn’t my money unless I believe there is a benefit to me.

Pica-Pica

13,829 posts

85 months

Sunday 6th January 2019
quotequote all
I am in the process of assessing different fuels for my 66 plate 335d. I usually run Shell V power diesel, the reason being in hope it will protect the dpf. However, I noticed a slight diesel knock on light throttles that was not there before; I was not sure if I was running Shell V power or had a tankful of Shell fuel save at that time. So I researched on line, and a few people were recommending BP Ultimate. Pricey, but the knock (which I must say very, very slight) went. I had two tanks of BP Ultimate, then topped up with Shell V power. Still OK, then on a nearly empty tank I topped up with Shell Fuel Save (standard Shell diesel) - result, knock returned after 20 miles or so. Again, I am in the process of next trying BP Ultimate, despite the cost, for two or three tankful, then Shell V power again to compare to BP Ultimate, and then back to Shell Fuel Save on it’s own, and then with additives. Apart from costs, the mpg has been similar, and any performance difference is impossible to gauge on the 335d. My main issue is to get back to no-knock on light throttle increases (such as when using cruise control). It will probably be a few months before I conclude anything.

That was all about fuels being able to minimise a particular knock. Additives may be tried in due course. Keen to hear other comments.

Evanivitch

20,135 posts

123 months

Sunday 6th January 2019
quotequote all
I used Miller's and then Rhino always found it made a difference to my MPG performance in a Skoda Davis PD TDi. Also tended to get documented improvements from most on the Briskoda forums, mainly from PD drivers.

I don't consider it snake oil.

SimonTheSailor

Original Poster:

12,617 posts

229 months

Sunday 6th January 2019
quotequote all
Some people are suggesting improved mpg - how much were you seeing ?

LarsG

991 posts

76 months

Sunday 6th January 2019
quotequote all
Pica-Pica said:
I am in the process of assessing different fuels for my 66 plate 335d. I usually run Shell V power diesel, the reason being in hope it will protect the dpf. However, I noticed a slight diesel knock on light throttles that was not there before; I was not sure if I was running Shell V power or had a tankful of Shell fuel save at that time. So I researched on line, and a few people were recommending BP Ultimate. Pricey, but the knock (which I must say very, very slight) went. I had two tanks of BP Ultimate, then topped up with Shell V power. Still OK, then on a nearly empty tank I topped up with Shell Fuel Save (standard Shell diesel) - result, knock returned after 20 miles or so. Again, I am in the process of next trying BP Ultimate, despite the cost, for two or three tankful, then Shell V power again to compare to BP Ultimate, and then back to Shell Fuel Save on it’s own, and then with additives. Apart from costs, the mpg has been similar, and any performance difference is impossible to gauge on the 335d. My main issue is to get back to no-knock on light throttle increases (such as when using cruise control). It will probably be a few months before I conclude anything.

That was all about fuels being able to minimise a particular knock. Additives may be tried in due course. Keen to hear other comments.
Suggest you have your car checked,

"Diesels actually do not suffer exactly the same "knock" as gasoline engines since the cause is known to be only the very fast rate of pressure rise, not unstable combustion. Diesel fuels are actually very prone to knock in gasoline engines but in the diesel engine there is no time for knock to occur because the fuel is only oxidized during the expansion cycle."

"Generally, diesel engines operate well with a CN from 48 to 50. Fuels with lower cetane number have longer ignition delays, requiring more time for the fuel combustion process to be completed. Hence, higher speed diesel engines operate more effectively with higher cetane number fuels."

In the EU Cetane level is set at 51.

"Diesel engine knocks when there is accumulation of fuel in the combustion chamber which happens when the injected fuel fails to burn as there will a huge delay period. And at a specific time all mixture burns simultaneously which causes increase in peak pressure and shock waves travel at higher speeds and can lead to permanent damage to piston crown and cylinder wall and head."

Therefore unless BMW say it can only run on CN 60 you might want to have the car checked out. There might be a software or sensor issue.

Edited by LarsG on Sunday 6th January 21:06

buggalugs

9,243 posts

238 months

Sunday 6th January 2019
quotequote all
I've been trying the Millers out the last few tanks. I always used to use V-Power diesel but the price difference between that and the stuff at Sainsbury's is so great now I thought I'd give it a go. I'm pretty sure there's less soot and it sounds quieter, as for MPG I'm not 100% sure there's maybe a small increase. At £1.40 per tank vs nearly £10 more a tank for V-Power I am gonna keep with it for a bit I think.

The only downside is I feel like a bit of a gypsy putting it in when I fill up.

Edited by buggalugs on Sunday 6th January 21:03

Glasgowrob

3,246 posts

122 months

Sunday 6th January 2019
quotequote all
always whacked a little bit of 2 stroke oil into the taxis

and we've run up some stellar mileages 400-500k without any problems never changed anything injectors or turbos on anything we've run the last 10 years

SimonTheSailor

Original Poster:

12,617 posts

229 months

Sunday 6th January 2019
quotequote all
Well I stick the cheapest sh*t in there, no V power this or super that.

My old 56 plate 112K mile Mondeo does 52/53 mpg on a commute driving through towns. On a run up to Scotland it did 65 on the way up there and 60 overall cruising around the coast.

I can't get much more than that surely ?

It does give a belch of smoke on hard sudden acceleration but it's gone after that.

LarsG

991 posts

76 months

Sunday 6th January 2019
quotequote all
SimonTheSailor said:
Some people are suggesting improved mpg - how much were you seeing ?
Depends how you drive.

Evanivitch

20,135 posts

123 months

Sunday 6th January 2019
quotequote all
SimonTheSailor said:
Some people are suggesting improved mpg - how much were you seeing ?
Consistently 2 MPG increase on an otherwise 60 MPG Fabia PD.

Deep Thought

35,847 posts

198 months

Sunday 6th January 2019
quotequote all
buggalugs said:
I've been trying the Millers out the last few tanks. I always used to use V-Power diesel but the price difference between that and the stuff at Sainsbury's is so great now I thought I'd give it a go. I'm pretty sure there's less soot and it sounds quieter, as for MPG I'm not 100% sure there's maybe a small increase. At £1.40 per tank vs nearly £10 more a tank for V-Power I am gonna keep with it for a bit I think.

The only downside is I feel like a bit of a gypsy putting it in when I fill up.

Edited by buggalugs on Sunday 6th January 21:03
Put it in when you get home?

donkmeister

8,208 posts

101 months

Sunday 6th January 2019
quotequote all
Welshbeef said:
I tend to also use a lot more nitro diesel or whatever it’s called. In winter starts much easier plus it’s also much quieter than regular diesel.
We used to add a little petrol to diesel to achieve the same effect... Albeit that was old mechanical and indirect-EFI engines so no idea if that would eff a more complex engine. Shouldn't do.

Northern.N

201 posts

141 months

Sunday 6th January 2019
quotequote all
I use millers in my Mondeo st TDCI.

Can really tell if I’ve not used it in a few tanks as it smokes a little on start up, doesn’t feel as lively either.

I thought it was in my head until the Mrs started noticing both of the above without my mention also.
A genuinely worthwhile product

LarsG

991 posts

76 months

Sunday 6th January 2019
quotequote all
donkmeister said:
Welshbeef said:
I tend to also use a lot more nitro diesel or whatever it’s called. In winter starts much easier plus it’s also much quieter than regular diesel.
We used to add a little petrol to diesel to achieve the same effect... Albeit that was old mechanical and indirect-EFI engines so no idea if that would eff a more complex engine. Shouldn't do.
Not in a common rail unless you want a big bill