For whatever its worth mazda tech that changed my oil said 5-20 oil is best for our car and sythetic is not good because it doesn't burn and is not best choice for rotary. I'm not trying to start a heated issue, just sharing info

 

the synthetic thing is a comfusing one, i knwo so many rx7 owners that swear by synthetic and i would have probably have swwayed that way as well, but i dont want to void a warranty after a month of having the car and a dealer might well do that if they were being petty,

do you think synthetic is better?


andrew

 

Stick with what is in the owners manual. Doesn't it already say 5-20 non-synthetic .

 

Where does it say non-synthetic? or mineral only?
Feel free to list the page number and manual revision.

Ford Motorcraft 5w-20 is a synthetic blend.
What oil is Mazda now using for most of their cars??

 

Check pages 8-9 and 10-5 (April 26, 2003). The types listed, API SL and ILSAC GF-III, are a non-synthetic oils. Castrol sells a 5W20 that is dino (what I got). There may be others, and just because Motorcraft (Ford) 5W20 is a synthetic doesn't mean it's ok. There are a number of threads in this forum which discuss this issue. Dino oil is the proper oil per Mazda.
Do what you will and suffer the consequences.

 

The owner's manual says to use SAE 5W-20, SL, GF-III. Most synthetic AND Dino oils carry this certification, and, while I don't see the reason to spend the extra money on synthetic, i'll be sticking with the cheapest stuff that the API say's meets its standards.

 

I will use non synethic, but the manual says change every 5k and the mazda tech said every 3k is better and I agree

 

The manual does say to change the oil and filter every 5k miles, (unless you live in Puerto Rico, however that matters), and, oddly enough the only people i've ever seen REALLY stand behind the 3K mile rule, are shops that change oil for a living. Oil purity and lifetime has increased every year, and modern machining techniques produce much tighter tollerances in engines, and, seeing as how nearly all car manufacturers are recommending anywhere from 5,000 to 7,000 miles (heck, schedule 1 for the RX-8 is 7,500 miles), I can feel safe letting it go a little longer if need be... basically, when i get around 3,000-4,000 miles, i start thinking about changing the oil, that way if i DO for some reason stretch it out ot 5,000 miles for some reason, i don't feel i'm doing any real harm.

Keep in mind that when the engine is new, i look at things a bit different... and more often is very good in the first few thousand...

 

everything being said has been said a thousand times before.

closing.