I know this is beating a dead horse but please give me some advise. Just picked my new 8 up from the dealer (AC AMP replacement) and we scheduled my very first oil change. I asked what brand of 5W-20 they used and he replied, we put 10W-30 in all of our cars, it won't hurt your rotary engine....

Is this acceptable or do I need to drive 50+ miles to another Mazda dealer that uses the recommended oil?

I'm concerned. Thanks for the feedback.

RKM

 

This can be a very subjective subject. There's ways to argue for and against the dealer, but when it comes down to it, the manual says use 5w30, so I'd tell the dealer that's what the manual says, and that's what you want in car. I don't believe 10w30 will hurt engine, but why not use what Mazda recommends. Even if you have to pick up four quarts yourself, and take it to dealer. It's not worth driving 50 miles to another dealer. If they don't have 5w30, then buy it at your local auto parts store, and take it to dealer, and if they don't have it, buy it online. Good luck!!

 

both my manual, and the oil filler cap for those who don't like to read the Manual, say 5W20.

IMO, if there's one or two things a manufacture's engineering department doesn't like to get wrong, it's their oil recomendation. It really PO's accounting and the warranty departments.

 

I think the brand was Valvoline.... 5W-20 should be at all the major auto part stores.

 

When I asked my service department what brand of oil they were using with the idea of using the same product for topping off. The answer I got was Chevron 5W30. I said but the manual calls for 5W20, they said we put 5W30 in everything (Mazda, Kia, and Isuzu). So I'm topping off with Castrol GTX 5W20 and will be supply same to my Dealer. When I asked Mazda about it their answer was short and sweet, "find a Dealer that will folow the spec.".

 

I run Castrol GTX 10w30 in our 8. It hasn't affected the mileage in the least. She is averaging 23 mpg. I went to 30w because of oil analysis' that people have been doing for trend analysis. They have the paper work that shows the oil is getting diluted to the equivalent of a 5w10 or 10w10 at oil change.

All cars outside of the US have a 30w oil recommended if I am not mistaken. I just cant remember if its 5w30 or 10w30.

 

Since the oil needs to cool the rotors, I plan to use 10W30 in the summer hotter weather and 5W20 in the winter. If you change the oil regularly and use quality oil, I really don't think it's a big deal. I put over 200,000 miles between my RX3 and 7 with no problems.