This is a scan of the 07, LMM GM Manual. It's for Canada but describes US also.
What Fuel to Use in Canada
Notice: Use of diesel fuel other than Ultra
Low Sulfur Diesel (15 ppm sulfur maximum) or engine oil other than low ash CJ.4 oil
will cause permanent damage to the DPF
and related components. This damage would not be covered by your warranty.
The emission control system requires the use of diesel fuel with ultra 10w-s\Jlfur (0.0015% by weight, or 15 ppm, maximum) content. Both Ultra Low Sulfur Diesel and Low Sulfur Diesel fuels are available in the United States and Ultra Low Sulfur Diesel fuel is available in Canada. However, only higher sulfur diesel fuel is available in Mexico.
At a minimum, the diesel fuel you use should meet the latest version of specification CAN/CGSB-S.517 (ULS) in Canada. In addition, the Engine Manufacturers Association (EMA) has identified properties of an improved diesel fuel for better engine performance and durability (FQP-1A). Diesel fuels corresponding to the EMA description could provide better starting, less noise, and better vehicle performance. If there are questions about the fuel you are using, contact your fuel supplier.
Canadian fuels are blended for seasonal changes; Diesel Type "A" fuel is blended for better cold weather starting (below O¬?Fer -18¬?C); however, you might notice some power and fuel economy loss. If Type "A" fuel is used in warmer temperatures, stalling and hard starting may occur. Diesel Type "B" fuel is blended for temperatures above OaF (-18¬?C).
It is acceptable to use diesel fuel containing up to 5% biodiesel (B5), but the final blended fuel must meet the same specification, CAN/CGSB-S.517 (ULS) in Canada, as other fuels used in your vehicle, and the biodiesel used for making this fuel must meet the latest version of ASTM specification' D 6751. Biodiesel is produced from vegetable oils or animal fat that have been chemically modified to reduce the possibility of damage to the fuel system and engine. Higher concentration (I.e., greater than B5) biodiesel-containing fuels or the use of unmodified bio-oils blended into diesel fuel at any concentration is not recommended and could damage the fuel system and engine. Such damage would not be covered by your warranty. If there are questions about the biodiesel-containing fuels you
are using, contact your fuel supplier. .