Low sulphur diesel
 

I note with interest that there is a big push to "low sulphur diesel"

This as we know is readily available in UK and most of Europe.

The problem seems to arise when crossing to Africa.

How much of an issue is it for newer vehicles with common rail injection to stick to the "low sulphur diesel" ?

Is it that it just runs crappy?

Is there a filter that can be fitted to remove some of the sulphur before it gets injected and burnt?

Please.

Hi uk_vette,

Please don't worry - the only reason to reduce Sulphur in diesel fuel is to reduce harmful exhaust emissions (Sulphur Dioxide in this case). Sulphur acts as a lubricant, therefore for diesel fuel injection systems (that are entirely lubricated by diesel fuel), having Sulphur in the fuel is actually an advantage - the low Sulphur fuel has to have an additional lubricant added to it to prevent damage to the fuel injection systems.

Performance-wise, there is absolutely no difference bewteen low sulphur and full sulphur and any diesel vehicle, regardless of age will run perfectly on either (assuming the overall fuel quality is the same)

With high sulphur content diesel generally it is a good idea to shorten the oil change interval - not a big deal, generally accepted Toyota standard for areas of poorer fuel would be oil and filters every 5,000km. So called 'mining' conditions (i.e driven like it's stolen and over rocks with 1 ton in the back) for some vehicles is as low as 2,500.

Our diesel here in Ghana is pretty crap quality and in the bush we have done back to back tests of two identically aged large machines - one with conventional mechanical fuel injection, one with high pressure unit injectors. On 5000hrs of use the conventional injection was shagged and plungers and barrels had to be replaced as the machine would no longer start when hot. Unit injected machine starts on the button the same as it did 5,000 hrs ago.

Has led me to believe that so long as contamination by particles is minimized a modern engine will actually arguably run longer on dodgy fuel - but regular filter changing and servicing is a must.

Gil

Hi Gil,

Thanks for the information.

Just a few more oil filters and oil Mobil 1 purchased locally?

I have the 2005 Land Cruiser, D4D which is common rail high pressure injection.

From what I hear, the electronics can adjust to cope with the fuel then?

However it must be CLEAN, CLEAN fuel.

yeah more regular oil/filter changes dont hurt.....

As Gil says in WA the diesel isnt low sulphur - its got a high sulphur content IMO - I dont think an excess of sulphur is good for the engine either personally as it reduces the cetane rating and reduces the engine oil life - my opinions - the sump oil is noticably blacker quicker over there from a combination of being worked hard (high load & RPM) and high sulphur content.

I made sure I did interim fuel filter changes between servicing - I saw a few bush taxis with shagged fuel pumps through lack of regular fuel filter changes and the generally poor quality fuel.

With a nice new vehicle id be tempted to put a 'pre filter/water separator' inline before the OE fuel filter:


Racor Diesel Spin-On Series Filters / Water Separators

BP were selling Low sulphur as far north as Kenya - don't know about west africa though - none in Zim (as with eveything else). As Gil says normal oil change intervals are halved in Africa - so every 3000miles or 5000km seems adequate for good quality oil changes. Good quality oil filters are expensive though - esp. Toyota ones - I have found Bosch or even Gud filters adequate and more reasonably priced.

Exactly! As Gipper and Bundu point out. The car will do fine, but important to minimise particulate problems - as Gipper says a spin on pre-filter like Racor or Separ or a CAV will be good, and you will probably find that you save some money on filters by changing the pre-filter rather than the high efficiency very fine OE one quite often. With the oil just make sure you are buying sealed, branded oil - shell or mobil etc. I say sealed as I have come across re-used oil containers where you cannot be sure what is inside.

Some info here:
http://www.enginemanufacturers.org/i...DieselFuel.pdf

So, firstly,
Engine oil changes 3000 miles / 5000 km. and Shell or Mobil from sealed new containers, using oil filters I bring with me from UK.

Secondly
Fit a fuel pre-filter.
I guess this will be mounted on the inside of the engine compartment, on a convienient bulkhead.
I have seen CAV "stand-alone" filters.
These have an upper housing, wich is also the securing to the bulkhead.
Then a metal filter is screwed to the underside of the upper housing.
The filters I have seen are perhaps 100mm top to bottom, and maybe 60mm diameter.
How will I know that the filter within is finer than the vehicle filter, so the new additional filter stops the crud, before it gets to the vehicle filter.

I will have to find out from Toyota or a filter manufacture, what filter properties the vehicle filter will filter down to, them buy a pre-filter accordingly.

Am I correct in the understanding?

You can avoid the need for en route oil changes due to high sulphur levels by using oil with a high TBN number, such as Millers XFD synthetic. This also works out cheaper and means you don't have to carry an extra supply of the stuff. One filling should get you to southern Algeria and back....

Total Base Number - Wikipedia, the free encyclopedia



Andrew

Thanks Andrew,

I learn some thing every day.

TBN was a total unknown.

Graham

With a CAV or Separ normally the idea is that the pre-filter is actually a higher micron rating and so is not as fine as the final filter before the pump. That way when your fuel is not so great you catch a lot of crud before and so reduce the "load" on the final filter - thus saving on expensive final filters. The OE final filter should be enough to protect your injection system, the idea is just to have a bit of extra security and avoid really frequent changing. Big advantage of the CAV type is that they are used by so many types of engine and so readily available, and that you can drain down water that settles from the fuel. I am not sure with the Prado if there are any real differences in a D4D "Europe" or "Africa" spec in terms of filter arrangements and so on. I will try and find out what I can as we are currently discussing buying a couple of Prados to replace two 105 cruisers. Unfortunately with the 105 discontinued the alternatives are now only 200 series (tasty but pricey) 76 series (leaf springs and those using the cars for weekend trips to the smoke won't thank me for that!) or the Prado. Will speak to local Toyota guys and see what they say.

Thanks Gil,

Now it becomes clearer, pardon the pun !

So for example, a pre-filter of say 10 micron filtration, and the O.E. filter of say 5 micron, (just an example)

If you can find out your end regarding the OE filter, then I can compare it with the OE in UK.

Wanted to resucitate this thread for two reasons:
1) For Graham: we ended up buying Prados with the good old 5L engine - so unfortunately I cannot provide any more info about african D4d... Nice vehicles, drove one yesterday and quite impressed. Only comment would be that the back end tended to skip around on terrible pot-holes and corrugations. Of course with some load and maybe lower tyre pressures I am sure it would be right. Although they are brand new Prados, they are really pretty simplified - part time 4by system as well as the simple engine.

2) On the issue of sulpher. Well, we decided to send off a sample to a German analysis company. Our fuel was fully within EN-590 (Euro Diesel Norms) except sulpher! Euro IV standards apparently specify 10mg/kg sulpher in Diesel now. Ours was 1410!!! Unbelievable difference.

G

Hi Gil,

I am glad of your feedback on the Prado.
So perhaps with a good load in the rear, then the backend could be a bit more planted.
Do you, on the short time you had the Prado, think it is up to the job of a trans-africa drive?
I don't think I would be doing too much off road, but then, I might look at doing more off road than planned, when I get there and get a feel for it.
the sulpher,
WOW, !
now that is a huge difference, but then again sulpher is no real bad thing for the engine, it is more of a lubricant, but clogs up the oil, just means the oil takes a hammering, and needs to be changed more often, like every 2000 miles for the D4d ?
Great to hear from a reliable source in the area.
graham

Many Euro 4 diesels have particulate filters and/or NOx converters that use AdBlue. These device are damaged by high sulfur fuel. This is why the mfgs insist on low sulfur fuel for Euro 4.
I think a Euro 4 will run on high sulfur, the "check engine" light or other warning messages will come on and you may need some very expensive exhaust parts replaced when you return. At least this is the deal with US EPA 2007 vehicles and I think Euro 4 and 5 are similar, with at least one converter in the exhaust stream.
Euro 3/EPA 2004 and earlier are fine with high sulfur diesel.

Charlie

sulphur problem or not
 

He Fox,

I am not so sure if Gost is all that wrong. As far as I know you shouldn't run a new car with Catalyst Converter on high sulphur fuel because it will kill it but for the rest no harm done! I know that low sulphur (new) cars have slightly retarded timing because the sulphur slows down the combustion, so lack of it increases the combustion speed hence the retarded timing on new engines. But it won't hurt the engine when its run on slower burning high sulphur diesel. It may cost some efficiency though.

Can you explain why cars will self destruct, there must be a technical explanation to it?


cheers,
Noel
exploreafrica.web-log.nl

Earlier this week I spent a few hours "chewing the cud" with a fellow who is a diesel fuel pump expert at Denso, the maker of Toyota pumps. So I put this question to him.

He mentioned the following things which are relevant:
1) Long periods with high sulphur fuel may shorten the life of the pump and the injectors due to the very high pressures involved in a common rail engine, but it is not a major issue.
2) Contaminants in fuel in these countries is a major issue. The most dangerous of these being water. He said he has seen lots of pumps which have exploded due to water contamination -and this is in the UK!!! He said that in Africa where water is really common in diesel this is a very serious risk.
3) Toyota have a policy of not selling high pressure common rail engines in countries with poor quality diesel. He mentioned South Africa as an example, (until their fuel quality improved recently). My reply was I thought South African fuel was pretty good, he said yes it probably is better than in other parts of Africa but is it poor by western standards. The impact of this is that if you do damage/destroy your common rail system, you will probably have real trouble finding an expert and parts to fix it. That is if it is fixable, as he said that when the do blow up they usually damage the engine too...
4) Mis-fuelling with petrol in a foreign country is much more likely. He said if you do, dont even start the car as petrol is really bad for common rail engines. It will destroy the pump immediately. So be very wary of this.

His advice:
1) He personally would never contemplate using a Toyota common rail engine in areas of poor fuel quality, but he is a pretty cautious guy anyway...
2) If you have a common rail engine in your Cruiser - then he said - fit extra water filters. He said a glass bowl type 1st, then a pair of standard Toyota fuel filters which would each have the small water trap. He said that the extra fuel filter would be beneficial too. He also said that if you do this you would need to fit a fuel lift pump if your vehicle doesn't already have one. He said doing this would reduce the risks to a modern engine to managable levels.

HTH
Graham

Hi Graham

Good info. Do all these filters restrict the fuel flow rate?

Cheers

Peter

That is what I was always lead to believe, and being in the developing world and buying a fair number of cruisers for fleet use I found it so:
- 79 and 78 series retaining 1HZ in Africa despite in Oz being released with the V8 d4d. Strangely this (essentially the same engine as the 200 series but minus a turbo) engine was released before the 200 series, which was rumoured to be delayed in release as Toyota had found issues with bad fuel in testing in Australia....
- Getting Prados with the 5L engine. But here I must point out that we bought them in EU from a dealer, and judging by the Arabic warning labels they were intended for another developing market.

So all this made sense - Toyo keeping old fashioned technology for markets where fuel quality is poor. But then they release the 200 series with D4D V8 officially in Ghana. I am very envious of a friend who has just got one - as a company car. Ridiculous (bearing in mind how much they cost!) but nice. So I am afraid that this seems that their policy of avoiding common rail in places like Africa is definately over. But to be honest as I have said before we have no single negative experience with electronics/new fangled injection types in VERY arduous use, and big global players would not be releasing products that are going to be potential disasters. If CAT and Toyota think common rail can be okay in such environments then I tend to think they may be right.

With regard to the extra filtration, any extra filtration is going to restrict flow. It is quite often that you will find people sticking in a small pusher pump (e.g. pacet or such) to help the the injection pump. We also do this on vehicles with sick pumps as it delays having to tear the pump down for a little while - i.e. you can start the damn thing! Separ make a very good filter with water trap, where you can choose the micron rating for the disposable element - we fitted them to MAN trucks and found them very durable if expensive.

As to the Prado, well I borrowed one as I was going on leave, meaning a good 8 hours behind the wheel on a variety of roads - good, bad and ugly. In the 3 liter form we got I found it VERY underpowered (a bit like the 105 series) but otherwise very good: comfortable, very sure footed/car like on good roads compared to 80/105/78 series, and fine on bad roads. In short I would be very happy to do a long trip in one. Much better stereo too! Obviously it is not a heavy duty vehicle in the sense of a 105 etc, but in reality unless the vehicle is going to do a lifetime of overlanding or work in forestry or mining then no problem. When we bought them we new it was a lighter vehicle, but better than paying $75,000 for a 200...

As I said I'm on leave, currently been enjoying a mini cooper s in Scotland and next week a Suzuki Jimny in rural Spain: should be interesting compared to big heavy stuff. Can't wait.
G