I went to car shop and tried to look for 5w-20 mobil one oil, but they didnt have any, only 5w-30? WHat kind of oil you use for your rx-8? Is it safe to use Mobil One 5w-30 instead?

This topic is being discuss all over in this forum, do a search.

I used mazda dealership since its free

I was advised not to use Synthetic Oil. My dealer is using Havoline of Valvoline 5W30 in the Winter and 10W 30 in the Summer becasue we live in the South (Georgia). 5W 20 will probably work ok in colder areas. Castrol makes a 5W20 and 30 .

welcome zoomin
it seem everyone has different thoughts on this right now
mazda tech told me 5-20 non synthic

so can we use super -syn ? or not use it?

I have had three techs and two dealers say NO to synthetics.

I'm going with Castrol GTX 5W-20 for my first oil change (doing it tomorrow at 3200miles). Next one will probably be synthetic (having had 160 thousand miles of personal experience with a rotary and synth).

ditto. just bought a case of castrol 5w-20 at pep boys.

I dont know if previous threads mentioned it or not, but I saw today in Mazdas own service manual (at the dealership) that synthetic oil is NOT recommended. I still don't know why they don't put that info in the drivers manual that comes with the car.

good point rxtreme