Mexican Diesel Fuel/Sulfur Effects Update

Ed White wrote:
I can only think that he was not computer literate so never located references to the extensive knowledge base about this issue on the net.

..or owner's manual literate.

DPF

The question of using Mexican diesel fuel in diesel powered vehicles built in 2007 or later comes up often on this forum. I am certainly no authority – we have a 2006 so this is not a concern of ours. Some say that many owners drive their newer trucks all over Mexico with no problem. Newer vehicles require ULSD which is 15ppm sulfur while older vehicles only require LSD which can contain UP TO 500ppm sulfur. Since I really know nothing about this I did some Googling and came up with some info and also more websites where more can be learned by anyone who is really interested. I have read somewhere that the vehicle ECM computer stores information about everything that happens with the engine and diagnostics equipment can read these computers – they will know if improper fuel is used and this could void the warranty. I sincerely wish all vehicles could be safely driven in Mexico and I encourage anyone with the proper equipment to visit Mexico – it is not my intent – now or ever – to discourage anyone from travel in Mexico. I have no other answers than what can be found below……Anyone can Google for lots more info……….

http://en.wikipedia.org/wiki/Diesel_particulate_filter

Wall-flow diesel particulate filters usually remove 85% or more of the soot, and under certain conditions can attain soot removal efficiencies approaching 100%. Some filters are single-use, intended for disposal and replacement once full of accumulated ash. Others are designed to burn off the accumulated particulate either passively through the use of a catalyst or by active means such as a fuel burner which heats the filter to soot combustion temperatures. This is accomplished by engine programming to run (when the filter is full) in a manner that elevates exhaust temperature or produces high amounts of NOx to oxidize the accumulated ash,[3] or through other methods. This is known as "filter regeneration". Cleaning is also required as part of periodic maintenance, and it must be done carefully to avoid damaging the filter. Failure of fuel injectors or turbochargers resulting in contamination of the filter with raw diesel or engine oil can also necessitate cleaning.[4] The regeneration process occurs at road speeds higher than can generally be attained on city streets; vehicles driven exclusively at low speeds in urban traffic can require periodic trips at higher speeds to clean out the DPF.[5] If the driver ignores the warning light and waits too long to operate the vehicle above 40 miles per hour (64 km/h), the DPF may not regenerate properly, and continued operation past that point may spoil the DPF completely so it must be replaced.[6] Some newer diesel engines, namely those installed in combination vehicles, can also perform what is called a Parked Regeneration, where the engine increases RPM to around 1400 while parked, to increase the temperature of the exhaust.

http://towprofessional.com/2013/12/dont-get-clogged-up-diesel-particulate-filter . . . where they say in part . . .

This is where the trouble begins. A clogged DPF filter can result in diesel soot backing up into the engine, causing damage to the VGT actuator, turbo, fuel injectors and EGR solenoid. Also, the unburned fuel injected into the exhaust system, as part of the regen cycle, can go into the crankcase contaminating the engine oil.

And……….

These DPF problems are so common that Dodge/Cummins owners have filed a class action lawsuit which has yet to be settled.


Quick look on eBay . . . http://www.ebay.com/bhp/diesel-particulate-filter . . . I see Mercedes Sprinter DPF very special deal only $1,250 and a Cummins for only $1,864


http://www.minutemantrucks.com/dpf-cleaning . . . cost of cleaning


http://www.worktruckonline.com/channel/fuel-management/article/story/2008/01/what-fleet-managers-should-know-about-diesel-particulate-filters/page/2.aspx


http://www.truckinginfo.com/article/story/2009/05/diesel-particulate-filters.aspx


http://www.fleetserv.com/service/dpf-maintenance/understanding-diesel-particulate-filter-maintenance


http://emissionsretrofit.com/products/diesel-particulate-filters

More can be found online.

Brian and Sue, you are correct, there is a lot of information about DPFs on the internet, but the data you have posted has nothing at all to do with the TEMPORARY sulfur poisoning that can occur when Mexican LSD is used while driving in Mexico. (LSD - Low Sulfur Diesel as compared to the ULTRA Low sulfur diesel (ULSD)in the USA)

I think it could be safely stated that I am considered to be an EXPERT on this subject, not only because I have studied and reported on it at length since early 2007, but I also have contacts within the automotive emissions programming community of the Big Three, so I have access to information about sulfur effects that is not generally available to the public. In addition, I have access in Mexico to electronic equipment that can instruct affected vehicles to burn the sulfur out of the emissions system when required.

In Mexico, the DPF (Diesel Particulate Filter) NEVER causes any significant problems, irrespective of whether it is fitted to a Dodge, a Ford, or a GM product. It is the SCR (Selective Catalytic Reducer) which suffers from sulfur poisoning serious enough to turn on the engine light and DEF warning. The SCR is responsible for reduction of NOX in 2013 and later vehicles which use Diesel Exhaust Fluid (urea) as part of their emissions system.

The DPF clogging problems referenced in Brian Sue's post are almost exclusively associated with earlier model years (2007.5 through 2010) which had regeneration programming that failed to adequately deal with stop start driving, such as that done by airporter busses and local delivery vehicles. There was a problem in ensuring that exhaust temperatures were high enough, for long enough, to "light off" the carbon in the DPF. This was overcome in later model years by programming that ensures high enough exhaust temperatures during regeneration, even if the engine is only idling, and forces regeneration cycles to last for at least 30 minutes.

Again though I want to point out that DPF clogging issues were extremely rare, and have nothing at all to do with the use of LSD fuel in Mexico.

As for fault codes remaining permanently in the ECR (on board computer) of vehicles, all of the codes associated with the emissions system issues experienced in Mexico AUTOMATICALLY ERASE after a regeneration, because emissions monitoring returns to normal. Even if a fault code did not erase though, it has no meaning other than to record an incident. For example, if one of the codes associated with incorrect NOX levels (P20EE or P2BAD) was present when an owner visited a dealership at a later date it would be of no interest to a technician. The normal conclusion would simply be that a temporary condition triggered the code and there is no ongoing problem.

I will post the text of an article on this subject in a separate post.

DIESEL FUEL IN MEXICO – AN UPDATE
FOR 2007.5 - 2015 PICKUP OWNERS


For those new to this topic, Mexican diesel fuel presently contains up to 500 ppm of sulfur, while the Ultra Low Sulfur Diesel (ULSD) sold in Canada and the USA is just 15 ppm. Unfortunately, the higher sulfur Mexican diesel can cause temporary “sulfur poisoning” of the emissions system for some pickup trucks with diesel particulate filters (DPF) and selective catalytic reducers (SCR). (DPFs were introduced in late 2007, SCRs were added by Ford and GM in 2011, and Dodge introduced SCRs in 2014). Your pickup truck has both DPF and SCR technology if you add Diesel Exhaust Fluid (DEF) to a separate on-board tank.


THE GOOD NEWS

Despite the potential for emissions system problems on DPF/SCR equipped pickups, laboratory testing prior to 2007 suggested that 2007.5 through 2010 model year diesels, whether Ford, GM, or Dodge, would tolerate well the higher sulfur Mexican diesel. This has indeed turned out to be the “real world” situation. There can be occasional bluish exhaust smoke during regeneration cycles, but no serious fault conditions are triggered. In addition, testing prior to the release of DPF equipped pickups confirmed that there would be no permanent damage to the emissions system, as long as higher sulfur fuels were not used for more than 40,000 continuous miles.

For 2011 and 2012 model years, some owners have been experiencing occasional engine light illumination, and “DEF QUALITY POOR” warnings. Those warnings typically disappear, however, following a 15 minute high speed run, OR during subsequent heavy trailer towing, OR after the next regeneration. All of these situations usually raise exhaust gas temperatures high enough to purge sulfur compounds from the system.

DEF QUALITY POOR warnings tend to occur a few weeks after a fifth wheel or other heavy trailer has been disconnected, and the truck is being driven around locally in Mexico. Lower exhaust temperatures while unloaded permit the buildup of sulfur compounds, reducing the efficiency of the emissions system until an error code is triggered. The Diesel Exhaust Fluid is NOT the culprit in these cases, even though that is the message displayed. It is simply a matter of the engine computer thinking that higher than expected NOX (oxides of nitrogen) in the exhaust is evidence that the DEF is not doing its job.


THE “NOT-SO-GOOD” NEWS

In 2013, Environmental Protection Agency monitoring requirements for NOX in the exhaust became much stricter. Monitoring is more frequent, and NOX must remain within a tighter tolerance level. In addition, regenerations to burn off the soot and sulfur compounds are less frequent. As a result, 2013 and later model year diesel pickups are more likely to register fault codes while in Mexico, and clearing the codes is more complex.

Also for GM 2013 and later model years, the distance which can be travelled after a DEF fault is triggered, and before “limp mode” (maximum speed 4mph) is initiated, gets accelerated with time. This means that the available non-limp-mode miles often disappear more quickly than warranted by the distance travelled, creating a stressful experience for owners.

Luckily, not every owner will experience such fault conditions, but when they happen, the key is to get the truck to do a regeneration as soon as possible. Once the emissions system is cleared of sulfur compounds by the heat of a regeneration cycle, the engine computer stops thinking that there is a problem with the DEF, and the fault condition disappears. It is critical that a regeneration be initiated well before limp mode occurs, because the vehicle must be driven at highway speeds for about 35 minutes during a regeneration.



FORCING A REGENERATION CYCLE

Unfortunately, there is no direct method for an owner to force a regeneration, but some pickup models have an indirect method based on EPA requirements that regenerations must occur approximately twice as often if there is a problem with the DPF pressure sensors. So, disconnecting the DPF pressure sensors can sometimes force a regeneration, provided that more than half the normal distance between regenerations has already been travelled.

Typically, immediately after disconnecting the DPF pressure sensors, the driver will see a message that soot filter cleaning has started and to keep driving at highway speeds until it is finished. If half the normal distance between regenerations has not yet been travelled, it could be up to 200 hundred miles before a regeneration is triggered, but odds are, for a fault to have been triggered by excess sulfur buildup, it is likely that more than half the normal distance since the last regeneration has already been travelled

Knowing how to unplug the DPF pressure sensors on 2013 and later model years will allow some owners to trigger a regeneration, which in turn purges the SCR of sulfur compounds, and clears the DEF warning. Detailed instructions are available for owners experiencing a fault condition, although it is more complicated when limp mode has already occurred.

Hopefully, Pemex will stick to the timetable it announced in September of 2014 to upgrade its refineries in 2015 and to have ulsd diesel available across Mexico by early 2016. If that happens, an annual complication for many Snowbirds will be eliminated for good, Irrespective of the manufacturer of your pickup though, if it requires Diesel Exhaust Fluid, be sure to take at least 5 gallons with you into Mexico. The only confirmed source in Mexico at this time is Napa Auto Parts, which will special order DEF from the USA at around twice the normal price.

Owners needing more specific information, or with a personal experience to share, can contact me at whitetmp@aol.com. Please note though that the information provided in this article, and to any owners who need assistance, is provided only in the interests of sharing of knowledge, and should not be interpreted as an endorsement or encouragement by the author for owners of 2007.5 and later pickup trucks to drive them into Mexico.


Ted White
January 6, 2015

Ed has not addressed the issue of the ECM retaining info that could eliminate your warranty. That 2103 PU had a new value of about $50,000. Does anyone really want to take the risk of losing your warranty? Ed's information is for PU trucks. If you have a DP motorhome the emission systems are totally different. The EPA and the Canadian authorities have begun to crack down on emission system tampering. Huge fines. Another risk.

Moisheh

It is somewhat amusing, and definitely puzzling, why there is so much animosity, and so many doom and gloom naysayers, in the RV.Net Mexico forum.

The various diesel truck forums on the net carry extensive discussions on this topic, dating right back to early 2007, but there are HARDLY ANY hysterical doom and gloom posts in the thousands of posts in those forums. People are interested in HELPING ONE ANOTHER, by sharing information and resources. As a result, owners experiencing problems with the fuel in Mexico are referred to me by those forums on a regular basis. Those owners are then quickly back on the road, with the problems fixed, usually at no charge, simply because of the open sharing of knowledge.

It is always a concern, of course, that an owner might do something that has caused, or could cause, problems with the warranty on his or her vehicle. For that reason, I am asking anyone who has knowledge about such an occurence, in connection with Mexican fuel use, to please post the true story here, or to contact me so that I can investigate. Inuendo, rumors, and warnings, are not representative of actual experiences, so they are of no use whatsoever in this discussion.

And in connection with diesel vehicles other than pickups, I am unaware of a single case of a heavy diesel experiencing significant fuel issues in Mexico despite having spoken with dozens of owners of late model motorhomes over the past 8 years. It appears that those engines are always handling a heavy enough load that exhaust temperatures prevent sulfur compounds from depositing in the emissions system. If anyone has even ONE example of a real problem, I would love to hear about it so that I can improve my database.

Moisheh has been "warning" people since 2077 of the disastrous things that will happen if they drive their late model diesels into Mexico, but has yet to provide a single example of an actual case. I invite him once again to show us the goods.

For everyone else reading this thread, please, if you come across a driver with a fuel related problem in Mexico, put that person in touch with me so that I can reduce their concerns and help them out of a worrying situation.

Damn, next time I'm in mexico I'm going to fill up on purpose. My 2000 F350 7.3 would love that sulfur.

hysterical doom and gloom

None of my posts have been hysterical or doom & gloom. I merely reference websites that have information about this whole situation. And I strongly suggest that owners of late model diesel vehicles contact the manufacturer (not the local dealer or mechanic - or any internet forum posts of unknown origin) for straight information from the horses mouth about what can possibly happen if you run improper fuel in your vehicle. Since we have seen and read of problems with these engines and exhaust systems even when run on proper fuel we have to assume there could be even more potential for problems with improper fuel. There are many experts out there who can provide both pros and cons about this whole issue. It is up to each individual owner to determine what level of risk they are willing to take.

There has been mention that things can be fixed (even in Mexico) if you do experience problems. We prefer to not have to fix things or figure out what needs to be done when we are far from home. Getting a well rounded education on this topic may be the best way to determine what decision you choose to make. Potential problems deserve 2nd, 3rd, 4th, 5th or more opinions - in my opinion. Make sure you KNNOW what you are doing as the consequences could be more than you might like to deal with.

ficials at PETROLEOS MEXICANOS are under intense pressure to provide UBA diesel for the state of Mexico. A formal threatening mandate.

Los refinaciones at Queretaro and Salamanca shall deliver the first Mexicano UBA.

I am of the opinion that "news" like posted above may not agree with reality regardless of its source.

Thanks for that input Mexicowanderer. Pemex has made vague promises about reworking its refineries to produce UBA (Ultra Baja Azufre)since 2009. It even showcased signs with the label UBA around that time. But, as often happens in Mexico, the timetable was never achieved.

This time around does seem to carry a bit more certainty though. The Pemex press release in September actually talked about $5.5 billion having been allocated to refinery and other Pemex infrastructure upgrades.

In addition, the United Nations Environment Program website recently started listing 2015 as the target year for Mexico to convert to UBA.

Let's all keep our fingers crossed.