rx7power

Right now i'm using 10w-30. I've been reading that you guys use 20w-50. How is that better for the 7. I have a 90 NA and i live in hawaii if that helps. Thanx.

the new guy ( hopefully I can quit being so new)

Icemark

20w50 is better for warmer climates that don't get any colder than 50'F (which sounds like where you live).

You don't need the cold temp protection that 10W30 will provide, but the extra bit of high temp protection will be better for your motor.

BTW: you want to avoid 10W40 in any rotary... to many additives to keep the range and typically a high ash content (whcih means carbon build up).

Ryde _Or_Die

I thought if anything you get better performance out of the thinner oil. Am I mistaken? Thanks.

Icemark

When I was talking about performance, I meant the performance of the motor oil...

If the oil is too thin, you won't get sufficent durablity of the oil or the motor it is used in.

Conversly if the oil is too thick... it won't flow as well to where it needs too and again, it or the engine fails.

But back to your question:

Short of synthetics (which generally shouldn't be used for rotaries, due to the high burn off temp and ash content when they do burn) there is little to no engine performance increase from one oil type or grade to another. Oils in most cases effect only engine life and protection... nothing more. However use he wrong grade, or poor quality, and you will be buying a new engine much sooner than you should otherwise. Oil does not affect engine HP output if it is the correct oil for the motor.

flubyux2

i changed my oil yesterday, and used Castrol GTX 10w40... are you tellin me i should switch it over to something else OTHER than the 10w40????

if u cant use 10w40...what is the acceptable stuff? cuz i dont wanna carbonize my engine all up.

chris

Icemark

In ohio, with winter coming I would replace it with 10W30 on the next oil change (within 3000 miles).

10W40 used to be all I used when I had american V8s, But I have been doing a lot of looking into oil lately, and yes the ash content (whats left after the oil is burned), is very high on 10W40 compared to 10W30 or 20W50, due to the additives they have to add to get the viscosity range.

See they would use a base oil- maybe 10W so it flows well when cold and then add stuff to it so that it flows to a 40W when warm. 10W40 has the most of these additives than any other oil.

I'll see if I can find that last report I just read and post it.

There are also some new findings that suggest that the oil first used in the car, actually coats into the metal's pores, and when you change brands, it actually rips the old impregnated oil out, leading to less protection until the new oild resets into the pores. I don't know how much is true on that, as it was an english study on Toyota/Lexus V8 motors... but I'll post it one of these days as well.

Ryde _Or_Die

Well I know the Royal Purple showed a 2% increase in RWHP on a dyno. I really want that stuff but don't feel like ordering oil everytime I need to change my oil.

flubyux2

what about Mobil1 0w30?

oh yea, in the jet ski world, we use 2 stroke oil, but i got a SeaDoo GSX limited. but its got the Rotax valve instead of a regular reed valve, and we have to use specific Bombardier rotax oil cuz it has a REALLLY low ash content, cuz you have to make sure that Rotax valve rotates and doesnt get seized up w/ leftover ash.

so WHAT if...i got rid of my OMP and oil injection, and ran premix w/ this Bombardier Rotax oil????

or, what if i just switched over to using the Rotax oil instead regular motor oil? somehow i dont t hink that would be a good idea, but i figure id ask anyhow.

chris

Icemark

That is a synthetic... even if it is petrol based.

Same with the Mobil One...

Other drawback to synthetics is that they typically are very low in Zinc content.
Zinc helps motors with wear (such as a motor with more than 30K miles), helping fill micro scatches.

Ryde _Or_Die

So what is the best oil for our cars? I am using Castrol GTX 10w30 now. What is the best for maintaining my car? Keeping it going with the least buildup? Please give me your personal brand and type. Thanks.

Icemark

Both Castrol and Valvoline are good choices. In a warm climate that seldom gets under 50, I would use 20W50 for any FC, and if you are seeing temps under 50 then 10W30 (-20 to around 80F, is the use range for a rotary to use 10W30) would be prudent. The Mazda owners and shop manuals seems to back this up.

5W30 would be only used in a rotary, if you are seeing temps around 20 or below as an average temp while operating the vehicle.

Pennzoil also has very low ash content, and by all tests seems to be a good choice, however as a personal choice I have not used Paraffin based oils like Pennzoil and Quaker State.

I have exclusively used Castrol in all my vehicles for 22+ years.

Ryde _Or_Die

So 20w50 Castrol GTX is good for me in FL? Thanks.

Icemark

thats what I would use.

Ryde _Or_Die

Thanks

Endur@nce88

i worked with a mechanic this summer and he told me that sythetics are the best oil to use. because under high pressure plain motor oil doesnt work nearly as well as sythetics. He's been in the mech. business for a good while now and me turned me to sythetics. my engine runs cooler now and i've noticed that my engine is a lot cleaner. there is a reason that sythetics are more expensive. i think its because its better.

Ryde _Or_Die

What I am getting is that synthetics aren't good for our rotories. Correct me if I'm wrong people.

Icemark

Generally no. Synthetics are not recommeneded. However some of the hybrids may be a good choice as their flash point is generally lower than a true synthtic.

I betcha that mechanic that says synthetics are the best doesn't work on too many rotaries or two strokes.

Here is a great link on ash content and oil properties:

http://www.vtr.org/maintain/oil-overview.html

Keith

Mazda does not recommend synthetic oil for the rotary unless you are racing it. That said, let me just state a couple of facts:

I have been running synthetic oil in rotaries since 1971 (My RX-2 would not even start in the winter without it). There is a guy in SCCA racing who has been running synthetics for 2 years without a single oil related rotary failure - as a matter of fact, he finished one race with almost no oil pressure due to a collapsed oil filter (musta been a FRAM ), and the engine was fine. Racing Beat, in the business of rotary mods since the early '70's, recommends synthetics for all rotary engines (Used to be Amzoil, now it's Royal Purple). The TII I just purchased used dyno oil, and at 122K I had to use ATF to restore compression.

My point? There are many people who, like me, have had great success with synthetics in a rotary engine. Let's not jump out there and condemn that with which we are not familiar. To all of you out there considering using synthetic oil, read all the pros and cons and make your own informed decision.

Irv, Keith's dad