Ed there is nothing preventing Topolobampo from getting diesel from Japan. A lot of Japan's diesel is sub 15 ppm. From Toplobampo diesel is barged across to Pichilingue. The Salina Cruz refinery is overtaxed as it is. Ernesto told me Pemex said it was running at 60% capacity and a lot of the diesel was committed to rural CFE generators. Old railroad locomotive engines with generators hung on the back. Salina Cruz refines a lot of number six fuel oil and pitch. Both used in large generator plants.
The same holds true for Guaymas. Salina Cruz is supposed to devote it's output to powering CFE generating plants up and down the Pacific Coast. Diesel fuel is secondary. As far as a guarantee of diesel fuel origin, good luck. Lazaro Cardenas and Acapulco are big diesel and gasoline eaters.
My hope is for Sempra Energy to get that Rosarito tank farm built fast. This is where premium gasoline is loaded into the tanker that brought up fuel oil from Salina Cruz for Tijuana's massive generator and sea water distillation plants. Baja's USA gasoline comes from the TESORO refinery in California. And this is where the premium gasoline for the entire west coast comes from.
Nothing would make me happier than ridding the country of low sulfur diesel and mediocre grade Magna gasoline. Some engines are satisfied with Magna. My Dodge bucks and stalls and forces me to either use Premium or spend a fortune on imported Chevron Techron additive. There is no excuse to sell Ubangi grade gasoline for four dollars a gallon.
My Kubota and my Cummins are perfectly happy with low sulfur diesel. I maintain scrupulously strict as hell measuring of kWh delivered versus fuel usage in my diesel generator. The consumption has not changed one whit in 18 years. As a reference, changing from #2 to ULSD is identical to have switched from number two to number one diesel. And you'd darned well better believe there is a 15% loss of economy.
As of a year and a half ago, my Dodge threw fits with Baja California Sur Magna gasoline. Exactly the same thing as happens at home in Michoacan. Up here in the northern state Magna is good, but throttle response is even better with BP fuel. Arco is not quite as good. !@#$%&! car is like a 10 year old kid staring at a plate of brussel sprouts. My Chevrolet Pickup trucks were never that fussy. They did not like NOVA however.
When Sempra builds the Topolobampo tank farm, ULSD is assured for Baja Sur as is excellent gasoline. Pemex uses USA Premium gasoline without alcohol and without Tesoro's additive package. But it adds MTBE. The last tank full of Pemex premium I got reeked of it.