hammertime

Hello all. I'm new to the rx8 thrill! Any input on synthetic oil? Thanks

gwilliams6

Welcome. There are extensive threads here on oil, dino and synthetic. Please read these threads, and then make your own decision as to what to use, as there is no ONE opinion about this subject !

Steve Dallas

This is a good place to start researching oil.

https://www.rx8club.com/new-member-f...4/#post4533706

Here is another good one.

https://www.rx8club.com/series-i-tec...cussion-52856/

This one too.

https://www.rx8club.com/series-i-tec...m-here-184241/

And if you still want to discuss oil, here is the place to do it.

https://www.rx8club.com/new-member-f...thread-248952/

archwisp

iTrader: (1)

The used oil analysis thread mentioned above is the main one you really want to look at. Read the reports from Blackstone and then form your opinion.

Nadrealista

Redline is pricey but they make top notch lubricants. I run their oil in engine, transmission and differential.

CaymanRotary

Synthetic if you run a Sohn Adapter. Conventional if not. 10W-40 to 20W-50 if in hot climate. 5W30 in cold weather. Always premix 2 stroke FC or FD rated at 8 oz per tank if decatted, 4oz if cat is still there.

Cosmo Canuck

Has anyone looked into running Amsoil Synthetic 2 stroke mix? Given that it works so well in saving chainsaws, etc with winter fuel (10% minimum ethanol and up to 7% more Methanol blends)
The other thing I see is octane boosters which just slow the combustion flame front propagation to stop ping rather than really boosting the octane levels.
Amsoil also makes Fuel PI that cleans injectors, and makes lower grade fuel run cleaner (Performance Improver) that has cleaned up many running issues before even setting a wrench to anything. The boost in fuel economy hasn’t hurt either.

I’m not a sales agent for Amsoil.

Loki

iTrader: (1)

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Is that premix rated JASO FD? If not then keep it for the chainsaw.
You don't need octane booster if you use the correct grade of fuel. Cheaper too.
Running injector cleaner once in a while isn't a bad idea. They're all basically toluene which is already present in higher grades of fuel.
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​​​​​​I know you're new here, but a lot has been written about oil for these cars, please read up.

CaymanRotary

AMSOIL Saber 2 Stroke is FD. Probably one of the best premix options available off the shelf. That company makes the best oils from my experience.

Cosmo Canuck

Amsoil’s Saber synthetic 2 stroke mix is JASO FD and higher rated. Use in all two-stroke handheld equipment where JASO FD,, ISO-L-EGD or API-TC oils are specified, including STIHL*, ECHO*, Toro*, Shindaiwa*, Craftsman*, 4-mix STIHL and Hybrid 4 Shindaiwa engines.
What ratio do you figure that the 4oz of 2 stroke currently suggested per tank works out to?

CaymanRotary

Generally mix 8 oz per tank if decatted. That will treat 16 gal of fuel. 1/2 oz per gallon a good enough ratio.

NotAPreppie

For the crank case, use any recent API (what are we up to now? SN?) oil, dino or synth. There's no solid evidence that either is a good or bad choice in a Renesis (though synth wasn't good for older rotaries before Mazda updated the material they used for rubber seals). If you still have a cat and don't have a Sohn adapter, avoid oils with lots of ZDDP and molybdenum because those are catalyst poisons and we are hard enough on those already. If your cat is already dead/missing or you have a Sohn adapter, use whatever. A high-moly oil (like Mazda-branded oil for SkyActive motors or Triax high-moly) might be a good choice since the molybdenum compounds in them are a really good extreme pressure lubricants that is good for bearings.

For premix or Sohn adapter...
JASO FD = ISO-L-EGD
https://www.oilspecifications.org/iso_2t.php

Ignore API specifications except for avoiding TC-W3. API TA/TB/TC/TD are all old and out of date while JASO FD and ISO-L-EGD are vaguely modern. Any oil that meets the JASO and ISO standards will exceed all API 2-stroke standards for on-land use.

API TC-W3 is formulated to limit environmental damage when used in watercraft. It might be better than nothing or it might not. Since finding JASO/ISO isn't hard, it's best just to avoid it.

My favored formulation was Lucas full synthetic snowmobile 2-stroke oil because it is available on Amazon Prime by the gallon and is darkly colored so it was easy to see the level in the Sohn reservoir at a quick glance.

BigCajun

iTrader: (1)

wannawankel

Right now the best bang for 2-stroke oil is Citgo Mystik 2-Cycle oil. It's typically $16 - $25 for a gallon at Menards and other hardware stores. Make sure you purchase the one labeled JASO-FD on the back since Citgo's labels are poorly labeled for the marine vs. on-land varietals.

wannawankel

Fleet Farm has it on sale for $17.99 / gallon! You can purchase online and have it delivered to the store. I've been running Mystik Sea and Snow in my backpack blower, snowthrowers, and RX-8 for a few years off the gallons I bought at Menard's on sale for ~ $14/gallon.

nycgps

iTrader: (1)

please just shhhhhh

Thanks

Cosmo Canuck

is that a fuel premix and lube combined or just for the mechanical portion?

CaymanRotary

Lol 0w-30 no thanks. Engine gonna get cooked on that. I want whatever Mazda is smoking.

Loki

iTrader: (1)

engine oil. Mazda doesn't endorse premixing.

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Don't be too upset at 0w30, the winter rating isn't the important number. The 30 is. Pretty sure Mazda put more thought into this than you.

Cosmo Canuck

Actually, Mazda started out with oil pumped into the Nikki carbs directly from the engine with the RX2 and R100 models, so they started the mixing of gas oil long ago. My first rotary came with a nearly seized, worn out motor because the original carb was replaced with a Holley and they left the oilers unhooked.

Loki

iTrader: (1)

And if you're driving an RX2, using carbs and oil from the 60s, that's would be relevant here.

You might have noticed they moved on to direct oil injection since then

Cosmo Canuck

Ergo why I came here to learn about the changes over the decades since I last owned a rotary. 😱

CaymanRotary

This the same Mazda that recommends 5W-20 in the RX8 for emissions reasons that helped destroy most of their engines? I did do research, there is no good reason to use such a low viscosity oil in the engine especially if it's over 50k miles. The only exception would be winter weather but would still run 5W-30 minimum. The engine bearings and seals require thicker oil to be properly protected.

Of course, while viscosity is important, it isn't as important as regular oil changes which is why synthetic is a complete waste of money unless running a sohn adapter so you can go longer between oil changes. This is why I run 10W40 Castrol GTX in all my RX8s and every single one whether I still own it or not is still on the road being useful.

NotAPreppie

The hatred of 5w-20 was based on one teardown at 100k miles.
The hilarity is that other things cause the engine to eat itself faster than the hypothetical problems with 5w-20.

Loki

iTrader: (1)

Did that research include a lab, test stands and multiple oil strategies for different regions? I'm gonna go with no. I'm gonna go with "google: rx8 oil". Close?
As soon as someone uses 'synthetic' to describe an undefined set of oils, they're behind on understanding oil, engines and how the two interact. It's a marketing term. Oil groups and API ratings are what matters, and those have progressed SIGNIFICANTLY since the RX8 was introduced and most of today's myths were written.

I don't have a horse in the fight about what you should run, I've been running LiquiMoly Synthoil 10w40 with 7-8000km change intervals for 6 years now with excellent used oil analyses each time and feel comfortable recommending it based on that. My current fill is near 9,000km and I plan to change it before Xmas. If you prefer to follow different dogma, by all means. Just don't spread the dogma.