Oil is oil, I agree. AND FOOD IS FOOD! Maybe that's why athlete's are eating constantly at the popular 'all you can eat' buffets along with the morbidly obese

An RX8 should be treated like a fine thoroughbred. Only the best should go into it. Will any old oil do the trick? Maybe for some but not for me; I love turning 9k. If you don't ever run the snott out of your 8 and you like changing your oil every 2000 miles then stick with the low grade fast food.

Paul.

 

As much as I want to, I can't completely dismiss that Consumer Reports study on New York Taxi Cabs that Wankelbolt posted, guys.

Even if I accept its results at face value, I will stick with Havoline, though. It doesn't cost much, is respected by a lot of knowledgeable people (especially because of the moly content), and I know that a reputable company that has a great additive package stands behind it.

The marginal differences between motor oils, as long as they're approved and the SAE has stamped them, is probably narrow at best.

Sometimes these oil discussions remind me of the oil filter discussions. We (and I include myself in this category) stress over the best oil filter to use (Purolator PureOnes for me), when I can't find any examples of oil filters leading to engine issues no matter where I look or how hard I look. But it makes me feel more comfortable knowing I don't have a POS fram filter, with cardboard backing, and sloppily glued components, and little relative pleat area, filtering my oil anyways.

There's a lot of emotional satisfaction in using 'better' stuff in cars we care about, even if it turns out that margin of difference between the average stuff and best stuff is relatively minor.

 

Well, have fun driving your RX8 like a 1992-1993 Chevrolet Caprice.

Here's a link to the full article: Consumer Reports "The Suprising Truth about motor oils"

 

Awesome information! Thanks to the OP for posting.

How is the oil filter decision that hard? There's only one option!
K&N.

Why? Cause my claws of hands are too damned big to get behind that motor so I use a rachet w/ a huge extension and a 1 inch socket to get that thing off. Problem solved.

 

I run 5w-30 in the summer. It get over 115 out here sometimes. But I dont want to change Oils. I have never had any probs with my set up. So I guess you can say I dont want to compromise anything

 

The oil debate is fueled by the fact that information is inconsistant, opinions vary and experts all say different things. It all comes down to who you believe rather than what.

I have people who I consider rotary experts. They have not steered me wrong yet, and I follow their suggestions on oil. I attribute the fact that none of these people have had to rebuild their motor from oil starvation issues or work in areas where they work on RX8's. I've changed oil a few times but I believe now that I'll be sticking with my current setup.

In terms of brand, it's been communicated to me that if you keep a fairly short oil change schedule (3000 miles or less) then just about anything is going to be fine. The primary issue comes from which oil burns better, which can be solved by using an OMP adapter and running pre-mix into the motor.

When it comes to oil, I feel a well informed owner can make decisons that fit their personal situation better than Mazda can. There are enough people and resources to educate you properly.

 

Just so people know my results are based off of a Mobil 1 oil filter. I was told by the company that ran the test the insolubles number tell you how your filter is doing. I feel it is doing a good job.

 

I like using the Mobil 1 Oil filter too. I was told there is a lorger one that will fit out car. Is that true? The guy use to post like mad on here back in the day his screen name is like Takahashi or something like that, anyway can I use the larger Mobil 1 filter too? or is that a no no?

 

Here are the results of my first 10W-40 Havoline sample. I must admit it was a bit disappointing. For the most part it really didn't perform any better than the 5W-30 sample. As you can see wear metals were all about the same, the additives were very similar which was a bit of a surprise after some things I have read, and even the viscosity still broke down.

I put in another 10W-40 Havoline to see if after two changes I see any other differences since in theory with this change I didn't get all the old oil out.

I think for the next change I may try Castrol 10W-40 just to do a comparison against Havoline and most members use that oil anyway so it may be informative to others as well.

 

Well, that kinda confirms my assertion that "oil is oil".

But your metal numbers do look a little better, and your viscosity numbers did come up. I screwed up and forgot to take a sample when I changed my oil last weekend, so we'll have to wait another 3000 or so for my next one. Did I post the results from my transmission? Metal soup...

Oh, and where's the commentary from the analyst on that report?

- Bill

 

Well, you are kind of paying way too much to have a nut epoxied onto the filter. You could simply buy Purolators (made by the same company), nuts, and epoxy and fashion your own for far, far less.

Or, you could buy one of these Lisle Tools filter wrench and save a lot of hassle. I've been using this since my first RX-7 20 years ago.
I haven't tried it yet, but the Purolator L20073 or equivalent is a much larger filter from the old rotaries. I use it on my race car. It's also dirt-freaking cheap at $1.30 each from Amazon. I doubt it will fit on the 8, but I think I want to try it.

BTW, I hate the filter location and position on the 8. It's completely stupid. And why couldn't they put the drain on low side of the filter stand! Then we wouldn't have to stuff a dozen paper towels in there to try to catch the leftover oil. Stupid, stupid, stupid.

 

what do you guys think about mobil one 15000 synthetic oil. It feels better for longer to me, compared to royal purple or conventional oil. with obviously the mobil one oil filter! I was on the royal purple tip for a while, but like I said earlier the mobil one extended life feels smoother for longer and doenst smell as bad!

 

I don't want to get in a synthetic debate (many threads do that already). Just for me I am going to stick with traditional oils for my tests. I would recommend after one of your changes to send your sample to black stone labs for analysis like I have been doing and see how the numbers compare. Also they have another test you can get for an extra 10 bucks which will tell you if you kept the oil in for too long. I figure rather than get opinions pay 30 bucks to get some facts. The numbers will tell you want you want to know I think.

 

As with all rotary engines if you poke hole in the top of the oil filter before you pull the drain plug, then the filter drains out, and you don't have to worry about using paper towels as you suggest.

Although the oil filter location in the RX-8 is a little harder to get too, it still is night a day better position than if you had some lame engine with the filter mount on the side.

Poke the filter and you won't have to clean up.

 

I've been poking the filter (in a platonic way ) in Mazda rotaries for 15 years. The 8 is the only one with the drainback hole on the uphill side of the filter mount. So there is still a sizable amount of oil left that has to be caught with paper towels or wind up on the engine and garage floor even after poking a hole in the filter.

Never had an engine with the filter on the side. But I can say Dodge trucks with the filter on the bottom front isn't much better. I'm just spoiled by the Mazda RX-7's.

 

It's a very fine, expensive oil that will do a fine job of lubricating your engine while evacuating your wallet of cash. Nothing wrong with it, just more successful marketing than actual superior engine protection.

"Feel" and smell have little to do with an oil's performance. Have you ever smelled quality gear lube? Holy hell it stinks! If you can actually tell how good an oil is by "feel", you can probably make millions in the oil industry.

 

You're looking pretty good actually. In order to see breakdown of viscosity you would need to send them a 'virgin' sample of the oil you're using. Your copper decreased slightly, that's a little interesting. Most importantly to me is that you have increased protection in a few key areas including viscosity. You can get the lab to give commentary with their figures, that's always neat to have as well.

Paul.

 

I think basically your 30 became a 20 and your 40 became a 30 over time. I think this is typical of conventional oils and the reason that I'm a little scared of starting with a 20.

Paul.

 

Plus, you end up with a used filter that leaks regardless of which end you stand it on. I save up a bunch before taking to the disposal center, so this just makes a bigger mess than dealing with the oil at oil change time.

We're blessed/cursed with bamboo on our property. I've found that a thin 4-ft long piece of bamboo is the perfect tool for tuking a couple of the ubiquitous red shop-rags around the base of the filter. A 1/4" dowel would work fine too. That's plenty to catch the overflow. When done, a cable/claw grabber retrieves the rags easily.

 

I drive 1000 miles a week in my baby, I can feel a new oil filter with out an oil change. smothness . . .

so yea, I can feel oil diferences

Im not trying to make anyone a believer, just stating my experiences . . .

and the smell I talk about is the exhaust smell, and different oils smell differently when coming from the exhaust.

 

buy it at super walmart, $25 for 5qts

mobil one 15000

 

Here are the comments for both samples.

Sample 1:

Thanks for the note. The fuel injector cleaner might be the reason that the flash point read a little low. Any contaminant can cause a low flash point, though usually that contaminant turns out to be fuel. It doesn't really matter--the flash point was still reasonable. The contaminant lowered the viscosity a little, so this oil ended being a 20W oil. Universal averages show normal wear levels after a ~2,700 mile oil run. This oil was run longer, so we expected to see iron read a little high. All other metals matched up well and that's a good sign.

Sample 2:

Protection wise, this 10W/40 looks very similar to the 5W/30, so we think either oil is going to do a good job for you. The additive package for both oils is very similar and about the only difference you can see here is the viscosity. The previous oil read down in the low 20W and this oil was in the low 30W. Iron was better this time, but the oil wasn't run as long, so we expected lower iron. Fuel dilution improved nicely and this reading of only a trace isn't a concern. Hopefully it will disappear next time. In any case, it looks like your Rotary engine is still doing well.

 

I wanted to post my last 2 results. Sample 3 was another Havoline 10W-40 and Sample 4 was Castrol 10W-40. The wear for each were about the same, but you can see the difference in additives. Seems Castrol uses about 1/3 Moly and seems to use some Sodium.

For me I think I like Havoline better between these two, but that is just me. My next oil is Shell's Rotella 15W-40. I expect to see some interesting additives used. We shall see how it compares to these other oils.

 

Can i ask where you sent your oil or did I miss it? Thanks.

 

I've been using:

http://www.blackstone-labs.com/