diesel fuel additives

[JimAttrill]

Like a lot of Seffricans (though also a Brit) I whack a bit of two-stroke oil into the tank on every fillup. I reckon I add about 250ml:100l which is 400:1 which is pretty low. But the engine (at 306 000 kms) does seem to start well and run smoothly at idle.

We also have (sometimes) the choice between cheepo 500 parts per million sulphur and expensive 50 parts per million sulphur diesel. I reckon the high-sulphur is better for the 300Tdi. Your UK diesel is almost sulphur-free, is it not?

If you want to read about the two-stroke oil business, the VW Tdi websites are full of info.

Personally I cannot see the 2T oil causing any problems because it is formulated to mix easily and to burn with no ash residue.

[Big.Mike]

I've put a tank full of the premium fuel in, particularly BP.

I knew a petrochemist once, she was working on diesel additives and (so she said) essentially, reverse engineering the additive products you've mentioned.

You might be better off giving the old girl a treat and a bit of nice premium! Yum, yum.

BP and Shells diesel definitely make my motors run better and more efficiently!

Additives, it's hard to tell... it's really hard to tell (mainly because I forget to put the stuff in each time)!

[rick]

Just a FWIW, some/most fuel additives can be corrosive to bearings etc. when they get past the rings (and they will)

BP used to market a very effective diesel additive here but I could see it straight away in an oil test with elevated lead, copper and tin levels !

I've mostly used Redline RL2 it's never had any noticeable effect on a used oil analysis.

[sparg]

Hi all

I had thought that it might be wise to use additives sparingly.

The results I've had over 2 tankfuls, just under 900 miles, - 31.266 mpg.

I've said before that, short of cruising at a steady 50 mph all day, the sort of mileage I do is probably the gentlest sort - not slow, but the majority of the journey is between 30 and 60, only about 15 stop /give way junctions (though I certainly use the accelerator appropriately). It's a double cab p/up 110 td5 with 120K on clock.

Unfortunately, I don't have quite as precise figures for consumption on the same roads without additive. However, I do now when I had to fill up, and I'm certainly getting an extra 40 miles (conservative estimate) per tank, and my estimated consumption was 27 mpg.

that would mean better than 15% improvement!

Next, I want to try a Bearmach tuning module I've just agreed to buy, to see if it gives me a similar power/torque performance.

In the meantime, if I can bear to go back to the old sluggish setup for a tankful, I should try to draw some more precise figures for the non-additive state.

[sparg]

Update:

I'm still using additive alternate weeks/ tankfuls, and consistently averaging 31.6 mpg in a 110 double cab pickup, TD5, 130K on clock. I also use 2-stroke sparingly - about 2-300 ml per 70 litre fillup - not really more power as such, but smooth revving ( I find a slightly harsh vibration under acceleration in higher rev range; no rev counter, so I don't really know what 50mph in 4th is).

The millers definitely smooths out the power at the bottom end - it will quite happily pull from below 30 in 5th (though not with breakneck acceleration) whereas before, I had to change down to accelerate to avaoid that kangaroo effect.

An unexpected result: cornering is better! - that is, dry country roads, 40-60mph, up and down speeds, the improved torque seems to translate into more surefooted planting on the road - and without being up and down the box.

[jbs]

http://www.dieselbob.co.uk/DieselFuel.aspx

[dave1607]

Been thinking about this for a while, so might give it a go and see how I get on. Which Millers additive is it that people are using? The one I have found on the Halfords website is "Diesel Power Ecomax"

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_370465_langId_-1_categoryId_255221

Dave

[sparg]

Been thinking about this for a while, so might give it a go and see how I get on. Which Millers additive is it that people are using? The one I have found on the Halfords website is "Diesel Power Ecomax"

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_370465_langId_-1_categoryId_255221

Dave

yep, that's the one I've been using. But see earlier postings about the possibilities that some additives contain contaminants whose long term effects may not be known.

I should say that I'm still experimenting with 2-stroke oil - it seems to make my engine smoother, but I haven't yet experimented with varying the quantity to find the best cost/benefit relationship. I've been cautiously using 250 ml per 70L tank. Whether I could have similar results cheaper by using old engine oil (from my own car) I don't know yet.

If anyone else is thinking of carrying out experiments - I've been quite experimentally 'sloppy' - really, to have anything scientifically valid, one has to be quite rigorous and objective about test procedures. It's hard to escape the possibility that one gets the result one hoped for - people subconsciously drive more cautiously when they are looking for an economic miracle.

So, I'm going to embark on a long term test over 5K miles (10 weeks) driven over the same route (my daily round trip to work is 95 miles approx) to iron out variations. I will not be able to compare this to 'before additives', since I didn't, if you see what I mean. If I had, i would have been able to separate the results (if any) of the "injector cleaning" function of the additive from the improved cetane effect.

However, I can say that, prior to additives, I covered more than 5K miles in the 110 doublecab TD5, and averaged just under 27 mpg, so I'll be using that as my benchmark.

So, if anyone else covers fairly substantial mileage in a defender of whatever type, and are thinking of testing, can I encourage you to be more rigorous than I've been in in objectively documenting 'before and after' phases of the experiment? keep an exact record of mileage, fuel receipts and amounts of additive used at every stage; you can't argue with real, hard data. After all, if my rather haphazard experiments seem to indicate a 10% improvement in economy (and some unquantified improvement in engine usability), that's a real result and worth telling people about

[sparg]

http://www.dieselbob.co.uk/DieselFuel.aspx

out of interest, why not old oil?

[Snagger]

out of interest, why not old oil?

Because it's full of very abrasive contaminants, like carbon and metal particles, and is also mildly corrosive.

[Litch]

Personally I have been using Redex in all my vehicles for a long time now (both pertol & diesel).

I do it on the assumption that it won't be doing any harm and by buying it at a decent price (4 x 500ML bottles for £11 from Costco) it is so cheap that the cost per fill-up is negligable.

[Jocklandjohn]

Same as Big Mike - I recently filled my 200Tdi with the expensive diesel at BP and its like a new engine. It's pulling like a train. making less smoke, is quieter, and the acceleration in 4th from 50 to 70 is noticeably improved. I'm going up hills in 5th I had to use 4th for before filling with the BP quality stuff. By contrast any diesel from T*sco does not work at all, smokes awfully, is noisy and runs like it's got one cylinder missing

[Retroanaconda]

I've found it makes no difference what the logo is at the top of the sign outside the petrol station. But have noticed differences in engine "performance" (if you will) from tank to tank sometimes, though with no correlation to supplier. I usually use fuel from JET petrol stations, though I have used BP from time to time and Tesco occasionally when I'm in the area. But I'd never go out of my way to get one type over the other, it's all to EN 590.

I wouldn't be suprised if Tesco diesel was just from whichever wholesaler is knocking it out cheapest at the time.

[jbs]

I long ago gave up using "Supermarket" type diesels in any of my vehicles as they're not as good quality as the mainstream suppliers and also don't have F.I.P. orientated lubricant(s) as the mainstream suppliers, a lot of my friends after I asked them to experiment with it also do not now use supermarket diesel fuel as they're under the same opinion as me, a couple of pence extra per litre I understand can be a little expensive If you were to fill the tank up from empty, but for the longevity of my fuel system(F.I.P./Injectors) and also the longevity of my engine I'll stick with main stream suppliers and live with the extra cost-It'll save me buggering about adding this and that into my tank and also dong what I need it to do-which is run smoothly and with quite a bit of power

John

[qwakers]

funny, my local morrisons is filled by a bp lorry. got chatting to the driver, he picks it up from the same tank at the depot as all the bp shell etc garages......

[V8 Freak]

All supermarkets buy from the Major Oil refiners, from the same tanks as their own stocks, with the same additives etc.

Tesco, Sainsbury's, Asda & Morrisons all historically also bought from the independant producers like Statoil, Futura etc. so none of the Supermarkets were totally dependant on the big oil companies. I don't know if this has changed since my last involvement in the industry.

In the majority of cases, the fuel in the supermarkets will be from the same tanks as the majors.

[Snagger]

I'd hazard a guess that the basic stuff is pretty similar everywhere, with small variations from forecourt tank water contamination. The big difference is that supermarkets don't stock premium diesels, which is why I now use BP where I can. Oddly, the Shell stations on my usual routes don't seem to have premium diesel either - anyone seen premium at a big Shell forecourt?

[Aragorn]

Most of the shell stations i use have both Vpower petrol and diesel.

My car requires the higher octane petrol due to it being turbocharged, because the higher octane fuel makes it more resistant to knock, thus i have no option but to buy the dear stuff. Can sometimes be a bit annoying having to hunt out a station that does the premium fuel when i'm away from home.

Not really sure of the advantages of the fancy diesel though?

[V8 Freak]

Well based on this thread I've bought a bottle of the Miller additive as I keep track of MPG on every tank. Ill report back in a few weeks after several tanks have gone through...

Neil

[Snagger]

Like several others reported here, I have found the premium diesel gives far better performance and economy, and smoother and cleaner driving. I suspect they also help keep the engine innards cleaner and the pump better lubricated. I find they cost more per litre but less per mile than standard diesels.

[Aragorn]

Fair enough, never had a diesel car to try it in!

Interesting on the cost-per-mile, i find the same with the petrol. The cars handbook says you can run it on normal fuel but expect reduced power. I guess the ECU has to retard the timing on the lower octane fuel, and perhaps run a bit richer to prevent knock, and thus ends up using more fuel.

[Snagger]

Fair enough, never had a diesel car to try it in!

Interesting on the cost-per-mile, i find the same with the petrol. The cars handbook says you can run it on normal fuel but expect reduced power. I guess the ECU has to retard the timing on the lower octane fuel, and perhaps run a bit richer to prevent knock, and thus ends up using more fuel.

It's simpler than that - the lower grade fuel burns less well, so you have to throw more in to get the same energy. Acceleration is reduced, so you spend more time in lower gears, and more unburnt fuel goes out the exhaust when cruising, which is why lower grade fuels create more smoke.

[Retroanaconda]

Like several others reported here, I have found the premium diesel gives far better performance and economy, and smoother and cleaner driving. I suspect they also help keep the engine innards cleaner and the pump better lubricated. I find they cost more per litre but less per mile than standard diesels.

Do you have any figures for this in terms of a cost-per-mile comparison over a certain mileage?

I ask as whilst I do not doubt that premium diesels are technically "better" for the vehicles by way of lubrication additives etc. I don't believe that they give sufficiently great savings in MPG terms to equate to a lower cost-per-mile. Even when you add in a potentially longer service life for fuel system components. Or if they do, I suspect the mileage one would be required to do in order to see a saving of any magnitude would be rather high.

However, anything with regard to fuel economy or performance is practically impossible to reliably test in normal life. Driving style, atmospheric conditions, road surface, vehicle condition, vehicle specification, driving route - just some of the variables one would have to exclude in order to produce good statistics. With that in mind, my opinion is just use whatever works best for you! Hence why I'll use any EN 590 diesel as I've never found any premium brand to give significantly better performance than the stuff out of Tesco's pumps or the like. So whatever's at the pump I'll take

[Snagger]

I haven't got any figures, but I did try it out a few years ago, recording odometer milages for each top up. I seem to recall geting around 5-6% better mpg, while the fuel is typically 3-4% dearer per litre. It isn't a major saving on fuel costs, but coupled to better engine conditions and also reduce transmission vibration from the smoother running, I think it probably helps on reducing maintenance costs, and it is much more pleasant to drive.

[V8 Freak]

Unfortunately James Tesco can't just shop around. They are the biggest fuel retailer in the UK, probably selling in excess of 100 million litres per week!!!

It all a very closely scheduled business so they and the majors need to plans to refine, store and land the product into the UK to an expected level of demand. With each tanker carrying 35000 litres or so they cannot shop around...

Really guys, its all the same stuff.