Cadillac 2007 DTS - Manual (Page 349)

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your
vehicle can affect the airflow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important
part of the proper maintenance of your vehicle.
To help keep your engine clean and maintain
optimum vehicle performance, GM recommends
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 may also use
regular unleaded gasoline rated at 87 octane or
higher, but your vehicle’s acceleration may be
slightly reduced, and you may notice a slight
audible knocking noise, commonly referred to as
spark knock. If the octane is less than 87, you may
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 might
damage your engine. If you are using gasoline
rated at 87 octane or higher and you hear heavy
knocking, your engine needs service.
Gasoline Specifications
At a minimum, gasoline should meet ASTM
specification D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines
may contain an octane-enhancing additive
called methylcyclopentadienyl manganese
tricarbonyl (MMT). General Motors recommends
against the use of gasolines containing MMT. See
Additives on page 350 for additional information.
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