ModMech
Platinum Member
There is no leagal mandate for cetane (although the EPA considers anything under 42 to be "unacceptable" for use in a advanced emission control diesel). Refiners and retailers are essentially free to sell any swill they choose and they DO NOT have to post the cetane rating or number (they aren't the same measurment, but either is typically representative).
Occasional "emergency" use of 40 cetane diesel will not "hurt" your engine, but it would not be suggested either.
Occasional "emergency" use of 40 cetane diesel will not "hurt" your engine, but it would not be suggested either.