Adding Equipment To The Outside Of Your Vehicle; Fuel; Gasoline Octane; Gasoline Specifications - Chevrolet 2007 Optra Owner's Manual

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 the engine clean and maintain
optimum vehicle performance, GM recommends
the use of gasoline advertised as TOP TIER
Detergent Gasoline.

Gasoline Octane

Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating is
less than 87, you may notice an audible knocking
noise when you drive, commonly referred to as
spark knock. If this occurs, use a gasoline rated at
87 octane or higher as soon as possible. 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 252 for additional information.
251