I'd like to ask for your advise on the following questions:

1) I'm living in Texas. Its weather is usually warmer than many parts of the country. Although Saturn recommends to use 5W-30 oil, what's the benefit of using (or not using) 5W-30 in comparing with 10W-30 - the most popular using oil (at least in my area)? Which one is better, which one should I use?

2) Everyone says synthetic oil is better than regular oils, and I'd like to try it (at least once to test).
a) Is it correct regardless about the prices?
b) People say that once I use synthetic oil in my engine, I have to use synthetic oil for the rest of the vehicle's life. Is this correct? They said if I go back to regular oils (5W-30 or 10W-30), it'd damage the engine?

Please advise. Thanks in advance.

 

1) Saturn recommends using the 5W-30 because of tighter tolerances in the engine which require a lower viscosity oil. The first number is the viscosity, which basically translates to how "thick" the oil is. Car manufacturers have discovered that tighter tolerances actually translate to longer engine life, if maintained properly. Putting the correct oil is imperative, regardless of where you live.
2) I have always said that if the engine is stock, and doesnt require synthetic, no need to waste the money. Again, the motor is engineered to accept regular oil, some engines (LS1 for example) require synthetic from the factory. Unless you have heavily modified the internals and have intimate knowledge about the engine's oil requirements, just put in what the factory recommends.

-JOE

 

To add to what hasn't been answered yet:You can change from synthetic to dino oil or the other way at any time...you won't ruin anything...
Edited by: sw2cam