Dodge 2013 SRT Viper Owner's Manual page 260

258 MAINTAINING YOUR VEHICLE
check the oil level is approximately five minutes after a
fully warmed engine is turned off or before starting the
engine after it has sat overnight.
Checking the oil while the vehicle is on level ground also
will improve the accuracy of the oil level readings. Add
oil only when the level is below the SAFE mark.
CAUTION!
Overfilling or underfilling will cause oil aeration or
loss of oil pressure. This could damage your engine.
Change Engine Oil
Refer to the "Maintenance Schedule" for the proper
maintenance intervals.
NOTE: Under no circumstances should oil change inter-
vals exceed 6,000 miles (10,000 km) or six months,
whichever occurs first.
Engine Oil Selection
For best performance and maximum protection under all
types of operating conditions, the manufacturer only
recommends full synthetic engine oils that meet the
requirements of Chrysler Material Standard MS-10725.
The manufacturer recommends the use of a full synthetic
0W-40 or equivalent engine oil.
CAUTION!
Do not use chemical flushes in your engine oil as the
chemicals can damage your engine. Such damage is
not covered by the New Vehicle Limited Warranty.
Engine Oil Viscosity (SAE Grade)
SAE 0W-40 engine oil is preferred for use in all operating
temperatures.