my advice would be to just follow the owner's manual and stop trying to rationalize doing **** to your car that doesn't follow manufacturer specs...

just my observation, but on a piston engine- yes synth oils do show more noticeable difference in engine smoothness... but, the Renesis is already one of THE SMOOTHEST revving engines... and, it doesn't really seem "necessary" to go synthetic. for one, mazda doesn't explicitly say to use it. second, there's not going to be that big a noticeable difference anyways.

ultimately, it's your car tho. so, do what you want. synth is also more expensive. so if u like wasting money... :shrugs:

 

General public is too dumb to figure out their own "optimum" oil weight for their local climate.

So instead of getting stupid calls every 10 seconds, the marketing department decided that its easier to just recommend something and be done with it.

People is getting spoiled ...

and people love to follow stuff that they want to listen.

When it comes to oil, people will say oh just follow manufacture's recommendation cuz thats what they "recommend/they know best/blah blah blah"

but When it comes to modification, which the manufacture ALWAYS have that "We don't recommend", oh this group of people will say something completely different. Hey I thought the manufacture knows best right? what happen now ?

Gotta love double standards.

 

Yeah - that sounds pretty stupid. Assuming that the people who designed and built a car might know the right oil to use in it.

Ken

 

These oil threads remind me of a dog chasing his tail.

 

You keep missing the point over and over again. No one here is arguing that synthetic oil will kill your engine. The point is that MNAO just might use the use of synthetic oil as an excuse for denying a warranty claim. It has happened.

Giving a new rotary owner--who is asking about Mobil 1 synthetic of all things--advice that synthetic is fine because MNAO don't know what they're talking about is bad advice. If you're going to use synthetic, then you need to know what you're doing and what the risks are.

Your argument that MNAO can't void your warranty because you know more about oil than they do is ridiculous. You don't get to decide who's right and who's wrong when it comes to warranty claims, they do.

If you think that a lawsuit will solve all your problems if you get denied warranty coverage, well, then you have a lot to learn buddy. About the legal system. Sue and you risk paying attorney's fees AND paying for a new engine. Even if you win, it may cost you more than an engine replacement. And it could take YEARS, you will have to go ahead and pay for the engine replacement or get another car in the meantime.

So go ahead and use synthetic, it's your car. Go ahead and tell the dealership techs that you use synthetic, it's your car. But telling someone who doesn't know anything about oil in rotary engines that synthetic is fine and MNAO can't deny a warranty claim because of it is bad advice, and in that case it's not your car.

 

MNAO has denied the engine warranty claim for a friend of mine on the basis that his oil "smelled funny". Yes, no tests or receipts to prove his oil use. It was done simply because a tech felt the oil didn't smell right.

This was on a Mazdaspeed Protege which had plenty of engine failure problems of its own.

Mazda can most certainly deny you a warranty claim if you do not follow their service requirements. If you demonstrate neglect by never changing your oil or using fluids outside of their requirements then don't expect the warranty to be honored.

Totally ignoring the suggestions or requirements of a manufacturer is silly. Lubricants are a major consideration during engine design including viscosity. Thinner oils are being used today due to tighter bearing clearances and better technology as the result of oil standards.

That being said, viscosity choice is based on engine operating conditions. This includes rpm, engine load as well as operating temperature. Thus far, there doesn't appear to be any seriously negative consequences from using higher viscosity oil but I'm not totally convinced it's necessary with a street driven car. Either way, the only way to make an informed decision is to understand how oil is marketed and also how your RX8 operates. This cannot be done using the stock dummy gauges BTW.

The aspect of synthetic vs mineral oil is a huge debate. Synthetic is superior to mineral oil and that's a fact. However, the price point doesn't always add up if you're doing short change intervals so people will opt for mineral oil and change it more often. There's nothing wrong with this.

We have people on this forum that base their engine oil decisions on reasons other than facts. Oil is almost always a "feeling" product. The only sure way is to have your oil tested.

I've now got 2 Eneos oil samples from their 5w-40 formula. One with 4,000 miles on it and another one with 5,000 miles on it. I'll post the results when I get them.

 

Marklar, post pics of your owners manual which states not to use Synthetic...

 

Man I am so tired of people calling bullshit.

By the way, if you read the thread about the guy who was denied warranty coverage, this statement in the owner's manual was what MNAO used to justify it. He had an '04 and this statement wasn't in his manual; they didn't care.

 

Im sorry but I did tell them I use Synthetic. Guess what, no issues whatsoever.

Not to mention, MNAO must be having some really special Rotary engine ... Synthetic doesn't work ?! oh wait, those engines came from Japan. Ahh they sell that Synthetic oil ~~~~

It might not be worth it for most (the lawsuit thing), but there are people who love to sue, I sued even the City of New York once to get about 1K worth of tire/wheel damage back. They declined the claim cuz they said my damage has nothing to do with NYC roads. Yeahhh ok.

All I need to do is prepare everything I need in advance. Hand it to the judge. Boom, 30 minutes later Im out with the smile on my face.

what MNAO don't want to get is more bad PR, you have to keep that in mind. For couple Grand Im sure they would rather settle than let this whole thing goes public. not to mention, if they **** enough people off Im sure someone will start a class action lawsuit, and Im 99.999% sure a lot of people will follow the suit.

Speaking of Bad PR, Mazda 3 and Mazda 5 just got a massive recall on the Power Steering Rack rusting and it caused 3 accident. Its not even old models, they are recalling 2007-2009 model year ~~~

Does MNAO want more bad PR? you ask me.