Castrol-GTX 5W-20.... I am pretty sure I read on the RX-8 manual that you are not supposed to use Synthetics on the RX-8... am I wrong?

 

Nothing in the manual tells you not to use synthetic oil. Be that as it may, however, the term "synthetic" is nowadays almost entirely arbitrary -- it's a marketing term, except for some of the "boutique synthetics" like Redline, RP, Amsoil, etc. For example, I use Motorcraft "Premium Synthetic Blend" 5W20, but it is not a traditional PAO synthetic.

I've advised many folks to simply use an oil that meets the manual specs and service ratings, and look for one that's certified for both the Honda AND Ford 5w20 specs. The Ford spec is the most rigorous.

I've gotten outstanding used oil analysis data so far, and it's only $1.50 per quart for the Motorcraft. I also recommend the Purolator PureOne filter. Don't forget the filter part of the oil equation!

 

Didn't know we had to put oil in these...




j/k

Penzoil 5w20, used to use castrol, haven't noticed any difference in consumption since the switch.

 

Just posted this to another thread. Also relevant to this thread:

Nothing in the manual tells you not to use synthetic oil. Be that as it may, however, the term "synthetic" is nowadays almost entirely arbitrary -- it's a marketing term, except for some of the "boutique synthetics" like Redline, RP, Amsoil, etc. For example, I use Motorcraft "Premium Synthetic Blend" 5W20, but it is not a traditional PAO synthetic.

I've advised many folks to simply use an oil that meets the manual specs and service ratings, and look for one that's certified for both the Honda AND Ford 5w20 specs. The Ford spec is the most rigorous.

I've gotten outstanding used oil analysis data so far, and it's only $1.50 per quart for the Motorcraft. I also recommend the Purolator PureOne filter. Don't forget the filter part of the oil equation!

 

NO!!! The manual states to use SAE 5W20, API spec SL engine oils. Nowhere does it mention synthetic, for or against. Look in your own manual!!!

As long as your chosen oil is 5W20 API SL, then it is fully and completely warranty compliant and permitted. If your synthetic oil is 5W20 API SL, then it is fine to use.

Mazda's lawyers have subsequently issued notices that Mazda does not recommend synthetic oil - which is far different than saying Mazda prohibits the use of synthetic oil, and using synthetic oil will void your warranty. Think about it.

Regards,
Gordon

 

So I guess it doesn't really matter. lol, thanks everyone.

 

Royal Purple Synthetic 5w20. Love the stuff, will never use anything else... EVER.. heh..

 

Oops, it looks like I also use Valvoline. That's what the dealer put in anyway.

 

That's not exactly true. My owner's manual says nothing about synthetic oil. (It never uses the word "synthetic" in reference to oil.) However, the car came with a booklet titled "Mazda RX-8 Driver's Guide" (part no. 9999-92-RX8D3-04). This states, "Add only non-synthetic 5W-20 engine oil with SL or ILSAC on the container label."

 

What oil does the dealership use?


my first oil change is coming up and the nearest mazda dealership is 45 mins away. I rather go to a nearby oil change shop.

 

Call around first. Make sure they have the RX8 in their service documentation/database. Make sure they have a 5W20 oil that meets ths specs in the manual. I tend to perform my own oil servie, because I know what I'm getting. I don't have to do it myself, but I enjoy it... kinda like "communing" with the car :D

 

Castrol

 

ohh ok, i thought i read somewhere that the dealer used a special type of oil on the rx8. So then its ok to go down to any shop that performs oil changes so long as I get 5W20 ?

thanks again

 

I' ve recently bought the car and i'm really confused about what oil should I use.
I' ve read a lot of things and i have to say i haven't reached any conclusion.
The Manual i got from MAZDA here in Greece says that i should use a
5W-30 oil API SG,SH,SJ or SL or ACEA A1 or A3 or
10W-30 oil API SG,SJ or SL.
There is not any reference about the usage of synthetic oi or a regular one.
I' ve read that many owners use 5W-20 oils of different brands and that they read that in the manual...
I' ve made 6.300 Km and used a Motul 300V 5w-30 100% synthetic oil to refill, but now the 2L bottle is empty.
Is this oil OK?
Should I use synthetic oil?
What does this API SJSHH SAE rawrtgt mean?
Finally whick IS THE BEST OIL TO USE???

 

Sorry to say that there is no definitive answer to this question.

If you search this forum you will find many, many threads that argue for and against using synthetic oil in the engine. The manual for North American models doesn't say you should not use a synthetic, but it doesn't recommend it either. Some owners on this forum believe that Mazda has not done long-term studies of the effect of synthetic oil on engine components, so they (Mazda) choose not to recommend it. My advice is to use a standard petroleum-based oil of the weight recommended in your manual.

 

For those of you using synthetic oil, I found the below alarming informationis on the Quaker State Motor Oil web site.


QUOTE

Myth #3

Using synthetic motor oil will void a manufacturer's warranty.

Fact
As long as the synthetic product meets the viscosity and performance requirements outlined in the vehicle’s owner’s manual, using synthetic oil will not interfere with the warranty coverage. However, one exception would be the rotary (Wankel) engine used in certain Mazda vehicles, which recommend against the use of synthetic oil in that particular engine.

UNQUOTE


Here's the link.
http://www.quakerstate.com/pages/carcare/whattoknow.asp

 

when I get my services done, I can pay extra for synthetic. It won't void a warranty.

 

A search will reveal more discussions of this topic than you could ever want to read, and they all say pretty much the same thing. Mazda used to specifically state in the manual that you shouldn't use synthetic oils in the rotary. They never stated why, there has just been some confecture, and in fact synthetic oil works very well in a rotary, as many people can attest (they usually just keep quiet however to avoid the never-ending arguments).

For the Renesis, there is no such specific prohibition in the manual, so I don't see how they would have a leg to stand on if they tried that.

One other thing...if you look at what synthetic oils are really made of...its the same basic stuff as regular oil! Its not like its some completely synthetic material that is unrelated. Unless you told Mazda, I doubt they would even know if you were using it.

jds

 

Thanks for the feedback. I currently don't use synthetic oil but I thought to share some related information with other members for what it's worth. But you're response in comforting for those that do use synthetic. DMP also has a good point. The dealer with charge you extra for sythetic oil if you ask. I'm sure if they would violate the warranty by using synthetic oil, they would make you sign a waiver.

 

Wouldn't a dealer that performs a service that voids a vehicle's warrenty be in a hole bunch of sh&t with Mazda?

 

The Mazda RX-8 Driver's Guide says:

"Add only non-synthetic 5W-20 engine oil with SL or ILSAC on the container label."

 

Who cares what they say in the driver's guide? I didn't get one with my car, and I know plenty of others who did not get one either. Its not in the MANUAL, they have no grounds for denying warranty coverage based on some poorly distributed "Driver's Guide."

jds

 

i could be wrong but i thoguht it was bad to run synthetic oil in the 8 i dunno thats just what i read a while back

 

no it's not bad...i've been running Royal Purple 5W-20 for the 2500 miles my warranted free factory oil change doesn't cover since i'm on the 5000 mile plan...i go 2500 RP then 2500 Mobil1...when my warranty runs out i'll go RP entirely...if my dealer would use RP instead of Mobil1 i'd be RP consistently now...

 

I've read those older posts and I'd like to put Mobil1 like my other cars but am scared between what Mazda says and what drivers say. I'm sure I'm not the only one stuck in the middle using conventional oil.