modern diesel for overlanding in developing countries - post your solutions


Expedition Leader
I was talking with a friend (hi, Bertrand!) about his plan to use a Mercedes Sprinter 4x4 as an overland adventure platform. I mentioned the issue of running an engine designed for ULSD diesel fuel on the high sulfur diesels found in developing countries. I didn't have a good answer, so let's use this thread to share solutions.

Short version: Is there any proven way to run an engine designed for Ultra-Low Sulfur Diesel on high sulfur diesel?

Long version:
To reduce emissions, modern diesels are equipped with complicated and expensive emission control systems. Equipment includes Selective Catalytic Reduction (SCR), supported by aqueous urea injection (Mercedes calls their system Bluetec). Urea helps the SCR remove oxides of Nitrogen (NOx). Electronically-controlled exhaust gas recirculation (EGR) is an older technology to reduce NOx, and many manufacturers use SCR and NOx in tandem.

The SCR system relies on fuel with reduced sulfur content, called Ultra Low Sulfur Diesel (ULSD). ULSD helps in two ways. First, less sulfur in the fuel reduces emissions of oxides of sulfur (S0x). Second, high levels of sulfur in traditional diesel fuel will coat the catalytic converter at the heart the of SCR system. A gummed-up catalytic converter can't be cleaned; it has to be replaced.

The EGR valve also has to be cleaned periodically. This is an issue for engines running ULSD as well as high sulfur fuel.

ULSD has only 15 parts per million of sulfur. Traditional diesel fuel has 500 ppm. ULSD is found at all diesel service stations in USA, Canada, and western Europe. South Africa, Australia and New Zealand have adopted ULSD. In other countries, finding ULSD is a hit-or-miss proposition. Outside capital cities (e.g., Buenos Aires, Santiago, Beijing, Hong Kong) diesel fuel is almost always traditional diesel with 350-500 ppm of sulfur.

A particulate trap in the exhaust reduces the soot produced by a diesel engine. The trap needs to be cleaned periodically, usually by injection of diesel fuel to "burn" at high temperature for a short period. Exposure to high sulfur fuel will gum up the particulate trap, requiring disassembly and cleaning.

All emissions systems are monitored by sensors connected to the engine's control module. When problems are detected, the dashboard displays one or more codes. Failure to rectify the situation causes the control module to put the engine into "limp home" mode, which limits the engine power and vehicle speed. Few mechanics and dealers in developing countries will have the diagnostic tools to identify and fix problems with a vehicle designed to run USA or European emissions controls.

So taking a vehicle that was designed to run on ULSD to a country that continues to use high sulfur diesel is a recipe for expensive problems.

Is there any proven way to run an engine designed for Ultra-Low Sulfur Diesel on high sulfur diesel?


Expedition Leader
One solution is to avoid the issue altogether. A diesel vehicle from model year 2006 or earlier will run on standard, high sulfur diesel as well as ULSD.

This isn't always an ideal solution. For example, the 2015 Sprinter offers 4x4 with low range for the first time in North America. A 2006 Sprinter will be rear wheel drive only.


Expedition Leader
"just remove all that emission control crap"

When today's complicated emissions controls were added to diesel engines, there was a response from the diesel aftermarket. Several companies offered DEF-delete kits. These ranged from simple exhaust pipe pieces to more elaborate systems that modified ("reflashed") the engine control computer.

The EPA stepped in and levied heavy fines on manufacturers that offered these kits without proof that emissions of the modified engine stayed within regulated limits. And the condition of the emissions systems is closely monitored by the engine control module. Any change will be quickly noted, and "limp home" mode invoked. If you think otherwise, post a link to a company that provides a solution.

The very best solution would be if the dealer could remove the emissions control equipment and reflash the engine control module to properly run on high sulfur diesel. But there are government penalties for this, too.


Expedition Leader
This should apply: Does not mention diesels, but the concept is the same. Without formal orders sending you out of the country, you would probably have to execute an affidavit and supply some form of documentary evidence that you are really making a trip. A copy of a shipping reservation might work. Driving south through Mexico might be a bit harder.

I have done this in the past. EPA issues you a certificate which you can take to dealers/exhaust shops, etc. This will also allow you to buy the "overseas" or "off road" chip tuners needed to bypass the SCR. You will still have to physically remove the particulate filter.

Just remember, you will have to reinstall all of this upon your return to the US.

Options also include having the work done in a foreign country if you can obtain the tuner.

This company offers products specifically designed for use with high sulfur fuel.
A while back I was looking for ways of upgrading my truck from Euro 3 to Euro 4 to enable me to enter London's low emmission zone without paying the fine. I ended getting exemption but was previously discussing my options with HUSS. They manufacture active DPF filters which use diesel systems to increase regeneration capability. They produce one system with a separate burner which they would warrant for use on high sulfur diesel fuel. Their equipment is intended for use in harsh off-road environments.

HUSS seem to work as OEM partners with Mack and Volvo so with some work, it may be possible to integrate their systems into the existing ECUs of other manufacturers and have it replace the standard system without setting off sensor warnings or limp modes.

Worth a look


Expedition Leader
I checked with Mercedes in USA. Two different representatives stated that "Mercedes-Benz USA does not approve or recommend any modification to the vehicle equipment." That's even with an EPA waiver. So a Bluetec-equipped Sprinter would have to be modified by a third party.

H&S Performance (link provided by Diplostrat above) is willing to remove diesel emissions equipment after the vehicle owner signs an affidavit specifying that the vehicle will be used off-highway, or out of the country. But they don't have products for Mercedes, only GM, Ram and Ford vehicles.

Euro 6, the current emissions rule package for diesels in Europe, is similar to the current diesel emissions rules for USA. It's possible that some aftermarket tuner in Europe has a solution. If you know of any, please post up.

(The Huss Group equipment linked by nick disjunct is an aftermarket solution to add a diesel particulate filter to a truck that doesn't have one. Their equipment is approced by the California Air Resources Board, among other groups. But this gear won't help remove Bluetec equipment from a current Sprinter.)
This guys gone around the world in a 2013 (?) Range Rover Evoque diesel.... I would assume he'd know if he'd had problems in Russia, etc.

Can't remember, or find a good pic, of his website chronicling the journey. It does have his email on it as I recall. I talked to him and a few other folks about using a 2014 US spec sprinter in Armenia. That postings not going to happen now, so its just filed away for reference.
I'm sure some members are old enough to remember putting "Dumps" on their high performance cars. Essentially it was a secondary selectable exhaust that bypassed the catalytic converter and muffler to increase power output.

What about a "dump" type system for your overland vehicle in conjunction with dual ecu programs (one when running ulsd with the emissions system and one for running regular diesel with only the basic exhaust).

If feasible it would allow you to remain emissions compliant while being able to run high sulfur diesel when necessary.

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I know that TATRA does have versions without all the emissions crap. None of their race trucks use it and I guess you can get it like that, if you ask for it. But the question is not about removing it, the question is: How would you ever get a vehicle registered without it? ;) You can go to a good chip tuner and get that EGR and DPF-regeneration cycles etc probably hacked out.
Tatra's engines are often referred to as "noise cooled" don't think you'd enjoy driving one too far.

These guys drove from London to Mongolia and down through China to ship a VW Touareg to Australia. Didn't bother with sticking to ULSD all the time, only problem they had was cured by using VAGCOM to run a few refresh cycles on the diesel particulate filter, needs a bit more to burn it out clean than the standard programming.
I personally prefer older mechanically injected diesels and turbodiesels, so I rather scoff at the idea of travelling with any engine electronics at all. Therefore, my solution to your problem is use an older truck with older mechanical technology.

Obviously, this solution might be completely ludicrous if you don't like old trucks.

If it's true the world sulphur map is not actually accurate, should folks be considering *gasp!* a petrol engine instead?
You get the same kind of issues when you can't get unleaded really you are just changing problems.

I know a lot of folks knock the modern electronics on engines and vehicles, but my experience is that you only need to adjust your skill set and fix techniques to reliably travel. Also, those electronics make vehicles much more reliable and efficient. In the world of off-road , they enhance the vehicles capabilities. That is what a Discovery 4 will out perform a Defender over equal terrain, with drivers of the same skill ( don't flame me folks, I love the Defender, but the truth is the truth).

I think the best plan is to take the time to understand the specifics of your vehicles emissions systems and develop a plan on how to deal with the need to possibly run HS diesel. Of course, you have to consider the necessity of replacing core components once you return.

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