Should You Drive A Diesel Vehicle To Mexico?

Can your 2007 or newer diesel truck or RV operate safely with Mexican low sulfur diesel when it is supposed to use ultra low sulfur diesel? Maybe. Maybe not. Read on.

This may soon be moot since the Mexican government will allow private firms to import gasoline and diesel oil as of April 2016. It will be 2018 before gas and diesel prices will be allowed to float.

This is quite a controversy and some people more educated than I argue vehemently for both sides of the question. Although I have been warned by manufacturers not to drive late-model diesels with LSD, I have personally only known two people whose late-model diesels had DPF clogging problems. Some argue that is fixable. I'll let you decide.

This link goes to an open letter published by Ted White who knows quite a bit about diesel engines and is considered an authority.

2006 engines were the last ones that did not require ULSD. (Check with your vehicle manufacturer. Some 2006 engines were put into early 2007 models, especially RV's). Don't take anyone's word except that of the manufacturer. Even if you can eliminate reset the sensors that reported the "bad" diesel in your vehicle, who's to say that EPA monitors won't find it? I remember in the late 1980's and early 1990's when unleaded gas was hard to find. People from CA were turned down for their state's smog check for having run a few tanks of Mexican leaded. I knew plenty of those folks.

OK, now that I have gone out on a limb, I'd like to point out that there is quite a conversation about a 2007.5 or newer diesel vehicle can safely use currently available Mexican diesel. See this authoritative web forum for a discussion.

As of late February 2016, there still is not any ultra-low-sulfur diesel outside a limited area around Mexico City and Mexico state. I do not expect the availability of ultra low sulfur diesel in Mexico to change soon - even though Pemex issued a press release promising abundant ULSD. I've been around the block a few times and remember such declarations about unleaded fuel in the past. Moreover, they promised plentiful ULSD in 2011, to my recollection. That was a long time ago.

I really want people to drive to Mexico, but I won't encourage you to gamble. Read that forum, talked to others and make up your own mind. If you have another vehicle, drive it to Mexico. Now that could change. Pemex could start selling ULSD fuel tomorrow. If it does, I will let you know. Meanwhile, try to make the best decision for yourself that will leave you comfortable.

For fuel costs in Mexico, see the Mexican fuel price page.

Should Newer Diesel Vehicles Be Driven To Mexico?

I have not gotten a straight story from Pemex or from the few gas station owners I know. But a reliable source in Mexico City to me that there is ultra low sulfur diesel (DUBA-- 15 ppm) and low sulfur Mexican diesel fuel (LSD [seriously]-- 30 ppm, (though one reader has some tested and found 500 ppm) depending on what state you are in. But all diesel is called low sulfur - you won't see anyone touting Diesel Ultra Bajo Azufre.

Ultra low-sulfur diesel (DUBA) has only 15 ppm of sulfur. It has 5% biodiesel so it has more lubricity. We all know that is a good thing. It was introduced to 50% of the Pemex stations in central Mexico (Mexico City, Morelos, Puebla, Mexico and others). It is being slowly introduced to a few stations in the rest of the country. Look for the sign, "bajo azufre" below the word "Diesel" on the gas station signage.

But I have to be honest with you - don't count on finding ultra low-sulfur diesel in Mexico. If you are afraid of putting plain low sulfur diesel in your tank, then don't drive to Mexico with your diesel vehicle.

RAM Trucks had this to say to me personally:

For newer diesels, still in warranty, here is what RAM trucks told me:

Dear Mr. Mike Nelson:

Thank you for contacting the Chrysler Customer Assistance Center.

If the proper maintenance or fuel is not used and it has been determined by our Chrysler dealer or technical personnel that failure was caused by improper fuel usage, then YES the factory warranty would be voided.

Cummins Diesel Engines says this on their website:

Availability of ULSD is very limited outside of North America and the European  Union – so it is critical to not operate an engine requiring ULSD in a country without available ULSD supply.  Using high sulfur content fuel will damage the engine and after-treatment system.

The state of Alaska had this to say on their website.

2. Will the newest diesel engines require this fuel?

Serious damage will occur without it. Sulfur in diesel fuel must be lowered to become compatible with modern pollution-control technology being installed on later model diesel engines. This equipment will reduce fine particles (soot) and pollutants in diesel exhaust by over 90%.

3. What happens if I fuel my new truck with the old high sulfur fuel?

Incorrectly fueling a 2007 model year or later engine with high sulfur fuel will damage the emission controls. The catalyst will be rendered useless and the emissions will not be controlled. Excess sulfur will plug the particulate trap which may cause a back pressure and possibly damage the engine. Fueling a 2007 and newer model year engine with high sulfur fuel will void the engine warranty and is against federal law.

I know many owners of older (pre-2007) diesel pickup trucks and RV's. They are happy using Mexican diesel.

I talked to a corporate representative from Ford, Mexico and he insists that the diesel in Mexico is low-sulfur and can be used in the newest trucks produced in Mexico. I'm not taking sides, just reporting what I have been told. I think he was confused.

The site fueleconomy.org says that LSD will make your engine hallucinate. At least they sternly say not to "just say NO" if you have a 2007 or later vehicle. And it COULD void your warranty.

For fuel costs in Mexico, see the Mexican fuel price page.