Could I suggest testing the stock Mazda 5w20 oil from the dealerships?

I think that would be a great place to start any comparisons...

Chris...

 

I think that would be motorcraft Synthetic blend 5w-20 right ?

Cuz I saw those @ 3 different Mazda dealerships and they use them for RX-8 as well as other Mazda cars.

 

I say Castrol GTX 10W 30 too.

 

Meh, don't know. The bottles that I buy at the dealership simply say "Mazda".

Chris...

 

There's no "stock dealership oil". Way back, when I used to get oil from Mazda dealerships, they would give me Pennzoil. I'm sure if I kept going back, their oil brand would change in a year or so again. They'll just sell you whatever is cheapest to them and whatever there is enough supply of at that particular moment.

 

There is a Mazda oil. but most dealerships does not care about it

like User24 said, They will just try to get whatever the cheapest, so they can *rip* the customers off with the biggest profit margin.

You can get Mazda oil, but have to order it thru dealerships, and they will probably think you're crazy.

 

In the US that is Here you pay $75 monopoly (Australian) dollars for 5 lites (5 and a bit quarts).

 

Could you elaborate on this? I thought I had heard that 5w-30 was better but Mazda (and other Ford vehicles, IIRC) was trying to squeeze out every last drop of mileage to get past the gas guzzler tax. Then a couple people on this forum told me I was crazy, where did I hear that nonsense, etc. Not that that means anything; people spout off nonsense on the internet all the time as you already know. I'm just curious as to what the real explanation is.

 

The move to generally lighter oils is probably just the natural evolution of motor oils - 20w50 was commonly specified "in the last century" and now is rarely required, as we get better components and base stocks.

....I personally use 0w30 all year round.

"No oil is thin enough at startup." - A.E. Haas

Link - http://63.240.161.99/motoroil/104.html

 

That is it in a nutshell.
Lower viscosity = lower internal drag.
Since the Renesis doesn't have windage, the gains are minimal, so the benefits of a higher viscosity far outweigh any gains from a "thinner" oil.
Higher viscosities withstand higher temperatures and convey more heat to the oil cooling system.
Somewhat higher viscosity oils also notably increase sealing as is observed in the increased intake vacuum at idle.

 

BTW - though the page referenced by Stealth is useful, some of it is misleading for a rotary engine where the lubricating function of the oil is different in the pan/bearings than in the seals/combustion chamber.
For instance, the cooling properties of a higher-flowing oil are not as relevant on the rotary because of the limited contact that the oil has with parts that are immersed in the combustion process, unlike a piston motor that has oil applied directly to the back of the pistons.
The heat extracted from the internally flowing oil must do so through the eccentric shaft.

 

MM-

So, being ignorant on the matter, and being an atypical driver that burns 2 quarts of oil per day per 2 day track event, what oil should I be running?

I'm still running the GTX 5w-20 because I don't know any better.

Thanks.

 

Wow! Good oil consumption! (Doesn't that phrase sound wrong!)

In an ideal world, you would run 0w-30. I don't think that is a prevalent grand (maybe it is, I haven't checked lately), so just run 5w-30.
Synth or dino, it doesn't matter for the most part, especially since your consumption rates are so high.

Generally, you want whatever oil gives you at least 15 PSI or so at idle and 80 or 90 PSI at redline when the engine is completely hot.

 

Damn...I thought that 1 quart a day was a lot.....Must be long track days....I burn about a quart in 2 hrs of track time....

 

Consider yourself lucky.
I spent a few hours at very high speeds on a mountain climb recently for about two hours and burned absolutely no oil whatsoever.

 

http://www.amsoil.com/storefront/tso.aspx

 

This is wierd. I only burn 1/2 qt. all weekend (2 2 hour days on the track) now. It was 1.5qts a weekend. And it's not because I'm slouching around the track ... I get 6.7mpg on track (probably a little less actually since I count the liesurely drive to the gas station down the freeway to fill up).

 

That seems way too low......I think the protocol must weigh heavily in the high RPM range for adding extra oil. I drive pretty hard around town and on HWY...but never burn much. Track days where most time is spent from 6-9K at WOT and It really pumps in the oil.

I'm going to get the Racing Beat mod.....I figure that the amount i already spend on track days...that it is good insurance.....even with pre-mix. Unless your testing comes up with an easy DIY to do the same thing.

From previous discussions..you pre-mix heavily anyways??

 

Staticlag,
I find your results very interesting, as they seem to back up a theory I'd espoused a while back in an ongoing "sythetic vs. the world" thread... namely that there are materials in synthetic oils which do not burn off, and that the design of the rotary combustion chamber and exhaust ports do not facilitate their removal due to centrifugal forces. I.E. they're going to collect on the apex seals, and in part, on the side rotor seals near the corners. Despite the cooling effect of each intake charge, at some point this remaining material will reach a near constant temperature somewhat lower than the combustion point. My idea suggests that it'll remain in a tar-like state, not quite ash, yet not fully fluid.

If you want so send me a clean container, I'll happily supply a sample of Motul synthetic... the same used by the Speedsource RX-8s which won 3 championships! PM me for my address.

 

Consumption has gone up with ability for me. My first DE I burned 1 quart over the 2 day weekend. This weekend I only got to DE for Sunday (worked a corner Saturday) and I burned a quart and a half...less than the 2 quarts usual because we had torrential downpours for 3 of the 5 runs, and I'd spun for my first time ever on my 2nd run of the day so I took it easy. To put it in perspective, I was running 2:45's-3:00's on the rain runs, and ran a consistent 2:19 on my last run yesterday.

Average mileage is 82 miles for 11.7 gallons (when I fill up) so that's slightly better mileage (AKA I'm slower than you) than you're getting.

Followup- As I'm in Houston and Dallas (hot climates), and especially since it's summer, switching to 0w-30 or 5w-30 would be good for the summer, at least? From what I've garnered just lurking these threads [I don't ever have any input, just there to learn], lots of 8 owners switch to 5w-30 for summer?

Secondly, as far as your third paragraph, I have no idea what you're talking about, or how to quantitatively measure that. In addition, don't even get me started on this car's idle. [though it's still rougher than an un-exfoliated elbow, it smoothed out significantly initially after removal of VFAD + addition of REVi, and then even more so with the addition of an ebay grounding kit]

 

In Texas you should just run 5w-30 year 'round, unless you want to use the Amsoil 0w-30.
I'm not a big fan of oils with a really wide viscosity range because it is additives that make that range and they boil off eventually.

I do pre-mix "heavily" (8oz per tank), but that is not really heavy if the OMP isn't doing much, if anything. That is only 225:1.

 

I use 5w30 all year around. Im thinking about going for 5w40.

Engine runs great and no problems. I've never been to a track. but if I wanna go fast , I can burn a quart in as little as 300 miles.

 

Damn, that 0W is expensive. I am in Texas and I run 5W-30 year round.

 

All AMSoil is around that on their site. at the NAPA stores in my area they are about $6/qt.

 

RP is similarly expensive.