What oil weight should be used in the summer for my 12a?

10w - 40w

20w - 50w

5w - 50w

What are the best oil brands to use?

 

I use 20w-50w in the summer and 10w-30w in the spring and fall.

 

20w-50 is pretty darn heavy.

From what I've seen regular old 10w30 is good. Just make sure you do oil changes pretty often, since these engines use oil slightly differently than piston engines. Oh, and one last thing.. DON'T USE SYNTHETIC!

Jon

 

In the climat you are in 10-30 sould be fine.

As far as brands are concerned, you are headed into a bit of a holy war.

Some people use Castrol GTX, Haovolin, is also popular.

A quick search of this forum under motor oil, or the like will complete the list of what people use.

It can not be stressed enough though

DO NOT USE SYNTHETICS!!!

 

Castrol GTX 10W-40. Don't leave home without it.

 

I use mobil 1 5w-50
you can use systhetics just fine if you disable the omp and premx

 

I'm a 10w-30 fan.
Currently using Havoline.

 

I use that stuff that comes on sale in a red container at Canadian Tire 10w30.. Then again, I also change my oil more often than the regular joe, so it's not like my engine has *time* to realize the oil is cheapo stuff.

Jon

 

whats wrong with synthetics?

 

synthetics dont burn very well if at all, and a rotary engine injects oil into the combustion chamber to lubricate the seals.

I use Castrol GTX 20W50 myself. Works great!

 

Valvoline 10w-30 here

 

Castrol GTX 20/50 in REPU.

Mobil 1 15/50 synthet in race car. I premix!

YEAR ROUND. I get longer life out of thicker oil. Takes longer to thin out. It will get to 85-110 this summer in socal (including the mohave desert where racecar gets driven).

 

i use castrol gtx 10w-40. so if you used synthetics the oil would build up in the engine...what does the omp do? is that what injects the oil on the seals? wouldnt disabling shorten the life of the engine?

 

I no longer believe the "Synthetic Oil" myth....everytime this comes up, I ask for a first person experience of someone losing an engine after 80,000 miles or so running on synthetic that was attributable to carbon'd apex seals sticking due to synthetic oil buildup from not burning up, and there is ALWAYS a deafening 'Net silence. It is an urban myth. Theoritical papers and bench guessing is great but utterly useless w/o testing or examples. My own experience is a 29,000 mile RP big streetport 12A that has survived 3 cars and several trips to the red zone when coolant hoses ruptured. Only a synthetic could maintain its viscosity under those conditions and that's all it's ever had since the 5500 mile mark after the break-in. It will power the '83 after the stock 147,000 mile engine dies under pressure from my little friend....

 

so you think synthetics are better? also, what is pre-mix?

 

I use Castrol GTX 10w-40 in the summer with a bit of MMO.

Pre-mix is when you put 2 cycle engine oil into your gas tank (this is especially for people who have disabled their OMP). I add a bit of MMO into my gas as a pre-mix.

FS

 

What exactly does pre-mix gain you?

 

No gain! People who don't trust their OMP disable it and then pre-mix.

 

a hell of a lot less carbon build-up
doa search someone ran ann engine and tore it down as a test

 

What are the major wear points in the engine, besides the apex seals, that a heavy oil would better protect?


Oil Metering Pump. Inject a very small amount of oil into engine to lubricate apex seals, and provide a compression seal. But regular motor oil wasn't designed to burn clean, so the oil injected into the engine with leave carbon deposits behind. Carbon deposits will foul plugs, and in extreme cases, limit the movement of the apex seals, which will cause a loss of compression= won't start.
The OMP can fail, and then your engine's apex seals will be running dry. Not good, but also rare.
Disabling the OMP allows the use of a premix oil added to the gas (not that you can't premix AND have the OMP working). Two stroke oil is designed to burn AND leave a lubricant residue behind, NOT carbon deposits.

I think most racers premix, but for street use? What happens when you forget to add oil to the gas that one time?

 

You cry..... But on a more serious note, DONT FORGET!

 

It's been asked again and again, but how much 2-stroke to a tank? 1L? Might as well re-iterate here.

Jon

 

why didnt mazda engineers use a seperate, small container to put 2stroke oil in for the OMP? also, whats the differences between 2 stroke oil and normal? what if you changed the oil using 2 stroke? is it too thin? low flash point or VI?

 

If mazda built the car to require 2stroke oil added to a tank, or into the gas. People would forget, engines woulf fail. And the cars would end up with a bad rep. Also if you put regular oil in your gas, it is to think and also is not ment to be burned in an engine. Two stroke oil is ment to be burned in a cleaner fashion as stated above. If used in as motor oil, it will not cool properly, and may have a risk off burning. I mean think about it, it's MADE to be burned.

 

"Two stroke oil is designed to burn AND leave a lubricant residue behind, NOT carbon deposits." --BRealistic


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So, we're saying that it doesn't hurt (and may help?) to premix even while the OMP is still operational?

Edit:
And would it have any adverse affects if one were to try it and return to regular fuel with just the OMP?