Re: 08 F250 super duty diesel fuel concerns
Yup, same thing here for us Yanks.
The engine could run fine on the higher sulfur, but it would soon mess up the emissions control parts of the exhaust system - the particulate trap and the catalytic converter. Having them messed up would confuse the engine control computer, and then it wouldn't run worth a darn.
I'm not sure how they handle it north of the border, but here in the states if you get caught with off-road diesel in a highway vehicle, it will cost you a bundle - they will assume you have always run off-road fuel and will back-charge you the per-gallon highway tax for all the fuel they figure you have used... and then there's the punitive fine on top of that.
By the way, even off-road fuel will be ultra-low sulfur in a couple years, at least in the states.