1. Go to
- Bob is the Oil Guy
2. Read through "motor oil university"
3. ????
4. Profit!
Since I know even in this crowd most of you are too lazy to actually do that, here are some key points:
*Oil does loose effectiveness over time. However, synthetic has the potential to last very long.*
*Never store oil in cold conditions.*
*Synthetic is significantly better in almost every regard, and WAY better in cold conditions.*
*First number in oil refers to "cold" thickness, second number refers to operating temp thickness. Since most wear occurs when the engine is cold, and you can never have an oil that's thin enough at low temperature, 0W30 is always a better choice than 10W30. They perform identically at operating temp, but the 0W30 provides better protection during warmup, where it's most important.*
My takeaway as far as frequency of changes was that synthetic can go a long time as long as your filter is working properly, but should be changed more frequently in cold climates. I have cold winters, plan on changing
twice a year with 0W30 synthetic as long as my filter seems to be working well. (Switched from Fram to Purolator after hearing some horror stories about fram. Purolator was still dirt cheap at Farm and Fleet)