Hi Tequila,
I can clarify most of the issues raised in your posting:
1.
There is ZERO chance that the diesel in Cabo is ULSD. I have two separate, very recent, emails from Pemex stating that the diesel in BCS (Southern Baja) is distributed out of La Paz, and is MEXICAN diesel which has been shipped from the Mainland, sometimes from as far away as the Yucatan.
2.
As further "proof" that the diesel in the Southern Baja is NOT ULSD, I had to assist more than a dozen owners of late model diesel pickups in the Southern Baja this last winter season because of temporary sulfur poisoning of the emissions system. One owner, who didn't find me until his truck was already in limp mode (5 mph)had a "delete kit" shipped down to La Paz from the USA and he removed the entire emissions system on his 2015 Ford. He had come down in a caravan and then travelled independently after reaching Cabo. A second owner on the same caravan, who also went independent after Cabo, visited the RV park I was in at Los Barriles and I had to force a regeneration on his 2013 GMC because it was close to being in limp mode. These situations only happen when the vehicles are burning LSD, which is up to 500ppm. There is not a single doubt in my mind, as someone who spends 6 months down there, that the diesel in the Southern Baja is LSD.
3.
The reason that pickup owners in caravans don't have any problems is because they typically remain hooked up to their fifth wheel trailers or travel trailers for most of the time. This ensures that the trucks are almost always operating under load, which in turn keeps exhaust temperatures above 350 degs C, preventing the deposit of sulfur compounds in the DPF and SCR. It is only when drivers leave the caravan, unhook their trucks, and begin driving around locally that they start having problems. Exhaust temperatures usually run less than 300 degs C under these conditions, and short drives where the exhaust system does not fully heat up, both cause the deposit of sulfur compounds in the emissions system, eventually leading to fault conditions and even limp mode.
4.
Motorhomes, camper vans, and van conversions, including those with Mercedes engines never report problems because the engines are ALWAYS running under load. Exhaust temperatures remain high enough to prevent sulfur compounds from depositing in the exhaust/emissions system.
5.
It is not true that the Diesel Particulate Filter (DPF) or Selective Catalytic Reducer (SCR) will suffer damage from using LSD (up to 500 ppm diesel fuel) during trips into Mexico. Extensive testing by the manufacturers of emissions components, and the truck manufacturers themselves, have shown conclusively that sulfur poisoning is TEMPORARY, unless the owner drives more than 40,000 continuous miles on LSD. Snowbirds and owners traveling in caravans return to the USA and begin using ULSD again long before they get to 40,000 miles. Once on ULSD, it only takes one or two regeneration cycles to completely rid the system of sulfur compounds. There is NO permanent or long lasting effect.
6.
I have extensive experience with GM products, which have the most problems starting with the 2013 model year, but all of the problems are COMPLETELY MANAGEABLE. There are methods which can be used to force regenerations to burn the sulfur out of the system. I personally had a 2015 Chevrolet Silverado 3500HD Diesel down in Los Barriles this year, and there were two 2013 GMCs in the Park. We all had to force regular regenerations while on longer drives, and none of us had critical issues. I personally helped more than a dozen owners just in Los Barriles last season, and I have trained 5 other people on the Mainland to help owners in trouble. There is no reason to avoid buying a late model truck simply because of the LSD in Mexico. Knowledge is all it takes to manage the situation.
7.
Last September Pemex announced more than $5 billion to upgrade two refineries to produce ULSD, but in February of this year, after the plunge in oil prices, Pemex announced that the upgrades would not proceed. Apparently only the engineering preparation will be funded at this time.
8.
There is ULSD at all border cities in Mexico under an agreement with the USA, and there is also ULSD in Guadalajara and Mexico City. This has been well publicised by Pemex and is part of the effort to reduce air pollution in those cities. Monterey also has ULSD, according to an email I received from Pemex.
I have been monitoring and collecting data on the subject of Mexican diesel and sulfur poisoning of emissions systems since early 2007. As a result, I have an extensive database of the effects on virtually every model year and make, and am also fortunate enough to have contacts directly in the Duramax emissions engineering department. This means that I have access to a lot of information about how the emissions systems work.
Hope fully this has cleared up some misconceptions.
