2009 Cadillac DTS Owners Manual PDF | Page 309

Keep a record with all parts receipts and list the mileage
and the date of any service work performed. See
Maintenance Record on page 6-15.
Adding Equipment to the Outside of
the Vehicle
Things added to the outside of the vehicle can affect the
air?ow around it. This can cause wind noise and can
affect fuel economy and windshield washer performance.
Check with your dealer/retailer before adding equipment
to the outside of the vehicle.
Use of the recommended fuel is an important part of the
proper maintenance of this vehicle. To help keep the
engine clean and maintain optimum vehicle performance,
we recommend the use of gasoline advertised as TOP
TIER Detergent Gasoline.
Gasoline Octane
Use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle?s
acceleration could be slightly reduced, and you might
notice a slight audible knocking noise, commonly referred
to as spark knock. If the octane is less than 87, you
might notice a heavy knocking noise when you drive. If
this occurs, use a gasoline rated at 87 octane or higher
as soon as possible. Otherwise, you could damage the
engine. If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
Gasoline Speci?cations
At a minimum, gasoline should meet ASTM speci?cation
D 4814 in the United States or CAN/CGSB-3.5 or
3.511 in Canada. Some gasolines contain an
octane-enhancing additive called methylcyclopentadienyl
manganese tricarbonyl (MMT). We recommend
against the use of gasolines containing MMT. See
Additives on page 5-6 for additional information.
California Fuel
If the vehicle is certi?ed to meet California Emissions
Standards, it is designed to operate on fuels that meet
California speci?cations. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, the vehicle will operate
satisfactorily on fuels meeting federal speci?cations, but
emission control system performance might be affected.