Cadillac 2009 XLR Automobile User Manual


 
If the vehicle has the 4.4L V8 engine (VIN Code D),
use premium unleaded gasoline with a posted octane
rating of 91 or higher. For best performance, use
premium unleaded gasoline with a posted octane
rating of 93. In an emergency, you can use regular
unleaded gasoline with an octane rating of 87 or higher.
If 87 octane fuel is used, do not perform any aggressive
driving maneuvers such as wide open throttle
applications. You might also hear audible spark knock
during acceleration. Refill the tank with premium fuel as
soon as possible to avoid damaging the engine. If you are
using gasoline rated at 91 octane or higher and you hear
heavy knocking, the engine needs service.
Gasoline Specifications
At a minimum, gasoline should meet ASTM specification
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 6-6
for additional information.
California Fuel
If the vehicle is certified to meet California Emissions
Standards, it is designed to operate on fuels that
meet California specifications. 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
specifications, but emission control system performance
might be affected. The malfunction indicator lamp
could turn on and the vehicle might fail a smog-check
test. See Malfunction Indicator Lamp on page 3-50.
If this occurs, return to your authorized dealer/retailer for
diagnosis. If it is determined that the condition is
caused by the type of fuel used, repairs might not be
covered by the vehicle warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel injectors
6-6