Originally Posted By: semaj281
Originally Posted By: jorton
City stop and go driving style puts more stress on the vehicle. Especially brakes and transmission so keep up with routine maintenance on those.
If Jeep puts your driving style in the severe service category you may decide to run short intervals, using conventional oil to save money. If you do do this, consider running 5w-20 or 10w-30 instead of 5w-30 because current formulations are too volatile and too much burns off leaving deposits and soot inside of engines.
You took the words out of my keyboard.
As for break in, it is best to run it hard once it warms up, and to vary the speed as much as possible. The point is to elevate cylinder pressures, so engine breaking followed by hard acceleration is ideal. Although at 400 miles, I would think most of the break-in is already done.
I wouldn't change the recommended oil viscosity on this engine. The cam phasers operate hydraulically. If you live where there is very cold winters (like where i live), you must start the engine and just let it idle for 10 minutes before you drive it. There are engines out now that have oil viscosity sensors and will disable the vehicle to prevent any possible damage. (1.4 liter FIAT Multi Air) Also the FIAT engine will not allow the engine to even start in ambient temperatures below -30C or -35 i cant remember exactly. As for the engine break-in period, i have direct info from Chrysler. (since i work as a tech for them) This also answers any questions about what quality the factory engine oil has.
"ENGINE BREAK-IN RECOMMENDATIONS
A long break-in period is not required for the engine and drivetrain (transmission and axle) in your vehicle.
Drive moderately during the first 300 miles (500 km). After the initial 60 miles (100 km), speeds up to 50 or 55 mph (80 or 90 km/h) are desirable.
While cruising, brief full-throttle acceleration within the limits of local traffic laws contributes to a good break-in. Wide-open throttle acceleration in low gear can be detrimental and should be avoided.
The engine oil installed in the engine at the factory is a high-quality energy conserving type lubricant. Oil changes should be consistent with anticipated climate conditions under which vehicle operations will occur. For the recommended viscosity and quality grades, refer to “Maintenance Procedures” in “Maintaining Your Vehicle”.
Caution!
Never use Non-Detergent Oil or Straight Mineral Oil in the engine or damage may result.
Note: A new engine may consume some oil during its first few thousand miles (kilometers) of operation. This should be considered a normal part of the break-in and not interpreted as an indication of difficulty."
So yeah they say basically not to drive the living [censored] out of it during this time, but also not to drive like miss daisy either.
As for when to change your engine oil, Chrysler says to change it regardless of what the oil change indicator says after 6 months or over 8000 miles.
"NOTE: The oil change indicator message will not monitor the time since the last oil change. Change your vehicles oil if it has been 6 months since your last oil change even if the oil change indicator message is NOT illuminated.
Change your engine oil more often if you drive your vehicle off-road for an extended period of time.
Under no circumstances should oil change intervals exceed 8,000 miles (13,000 km) or 6 months, whichever comes first."