Yes, you can even mix them together with no problems.
Yes, you can even mix synthetic with conventional oil.
I will change my oil from conventional oil to synthetic oil on my next oil change.
Yes, you can mix them.
The engine uses 5W30. It can be synthetic or conventional.The engine uses 5W30. It can be synthetic or conventional.
Yes, without any issues. That's what synthetic blend oils are (better than conventional oil, not quite as good as pure synthetic).
Yes, you can mix them.
Oil changes are always necessary. If you mean can you mix conventional oil and synthetic, the answer is yes you can.
No, I would not recommend using synthetic in an engine this old. Use a good 10w40 conventional oil.
No it is fine to switch back to regular oil.
Change the oil and filter every 5,000 miles if you are using conventional oil or every 7,500 miles if you are using synthetic oil.
Yes, you can use synthetic oil in a 1999 Mazda 626. Synthetic oil offers better protection and performance, especially in extreme temperatures, compared to conventional oil. However, it's essential to check the owner’s manual for the recommended oil specifications and change intervals to ensure optimal engine health. If the engine has been running on conventional oil for years, consider a gradual switch to synthetic to avoid potential leaks.
conventional. I wouldn't put synethic in it unless it has already had it in the engine. Synthetic is mostly used in high performance or new vehicles. Synthetic won't do anything for an older engine