Mazda RX8 and proper oil question

[Schism]

Yep, 5-20 degrees less is what most synthetics run compared to dinos according to most of the websites i've looked at, and this forum. Mazda obviously knows nothing about synthetics they even recommend against it in their manuals for other cars too.

[ August 22, 2005, 02:28 AM: Message edited by: Schism ]

 

[oktobernv]

Well, I got my RX8 back from Magic Mazda here in Vegas last friday.

New engine.

I asked the service rep what "brand" of oil Magic uses.

He said they use HAVOLINE 5w-20 for the RX8's

Any more thoughts on that?

Rob in Vegas

 

[Drew]

I would dump that 5w-20 and put in a 5w-40 oil for year round use.

I'm on my 4th rotary engine and would never consider such a thin oil. Also, it wouldn't hurt you to add about 6 oz of ashless two stroke oil to each tank of gas to improve the internal lubrication. Mazda has significantly cut down the amount of oil injected in this engine to meet stricter emissions.

 

[ZoomZoomH]

boy am I glad I'm not living in Vegas...

 

[ZoomZoomH]

and as for oil, I used Motorcraft 5w-20 for the first 10000 miles or so on the car. Recently switched to Castrol GTX 5w-20. now has 16k on the car, and running flawlessly

oh and i run 3000mi OCI

 

[ZoomZoomH]

oh, and start doing UOAs beginning with the very first oil change on this new engine

an UOA on the samples of the oil on the blown engine may have gave you *huge* warning signs that the oil is degrading rapidly, and that something is definitely wrong.

 

[ekrampitzjr]

To muddy the waters even more, here's a thread that yours truly started many months ago:

Mazdaspeed synthetic rotary engine oil

Another thread posted sometime back linked to a PDF copy of a Mazda Australia document saying that synthetic oil was okay in the RX-8, but not in earlier rotary engines because of supposed seal compatibility issues.

Quite a few racers and rotary buffs have been running the better synthetics in the Mazda rotaries with no claimed ill effects: Amsoil, Red Line, Royal Purple, even Mobil 1. Based on older specs for rotaries, 5W20 in dino or synthetic seems a bit thin, but much of this has to do with Ford controlling Mazda.

However, a number of racers and aviation types running converted Mazdas in aircraft have gone to a premix using a good 2-stroke oil. I have wondered how Marvel Mystery Oil would do as a premix (with or without the original motor oil metering system functional).

My question is this, as it isn't clear from the posts on this thread: How are all these RX-8 engines failing? That is, what is the failure mode, and what is the evidence? Could it be that a bunch of ignorant Walter Mitty poseur types are buying these cars and then neglecting to maintain them?

 

[The Critic]

quote:

---

Originally posted by oktobernv:
Hello All.

Rob in Vegas here, got a question.

We have been having a HUGE problem with Mazda RX'8 blowing engines in the Vegas heat this summer.

One dealership alone (Magic Mazda) has already replaced over 20 engines this summer.

These are 2004 RX8's with between 10k and 20k miles on them.

The general theory seems to be that the oil coolers on the cars are not robust enough.

The oil is heating up and eventually turning to sludge. The engine temps are getting WAY high and eventually the APEX seals on the engines are "warping"

Causing a lose of compression and then engine failure.

Mazda ONLY recommends 5w-20 for ALL RX8's

No matter what part of the USA you are in.

This was apparently done to satisfy EPA regulations about emissions with the RX8's.

Mazda does NOT endorse ANY syn oils.

My question is this.

What grade and type of oil would you recommend for HIGH temps like we get in vegas. This summer we had a stretch where temps were between 112-118 for about 2-3 weeks straight.

Most people here do A LOT of city driving. Very little long drives, very little freeway.

Some people have reported engine OIL temps in the RX8's hitting 240+ degrees.

Any thoughts would be much appreciated.

Rob in Vegas.

---

Next best thing, IMO, would be to use a quality blend such as Schaeffer's 5w-20. It'll satisfy Mazda and perform better than just a straight dino.

MW

 

[Drew]

They are failing because they are less tolerant of:
1. being driving hard when the engine is cold.
2. low oil level
3. low coolant level

Get low on oil or overheat your engine and it needs to be rebuilt. Not rocket science.

With that said, I've never blown a rotary and I have about 325,000 miles on rotary powered engines in the past 15 years.

 

[Drew]

I am on my 4th rotary powered vehicle since 1986 and I only feed them a diet of 10w-40, 5W-40 diesel oil, or 20w-50 when I lived in lower Alabama.

You are doing yourself a disservice by running a light weight oil in a rotary engine. It is not unusual for fuel dilution and shearing to decrease the viscosity of a 20W-50 down to a 20w-30 in as little as 3,000 miles.

Please, please, please, do not leave that 5w-20 oil in your newly rebuilt engine. You are only asking for more shop time as far as I am concerned.

Andy

PS It would not hurt if you added 8 oz of 2 stroke motor oil to each tank of fuel. The Rx8 motor injects 1/2 of the oil than the older generation motors. A no go in my book only meant to reduce emissions at the cost of your enigne life (apex and side seals)

 

[zoomzoom]

curios what happened to that rx-8 from vegas? how long did new engine last?

 

[SilverC6]

In my son's '04 RX8, I use 5W-30 YBP and a squirt of 2 cycle oil in each fuel fill up and have been pleased with the results.

I try to keep it changed often @ 3000 mi. to keep fuel dilution at a minimum.

I wouldn't be too concerned about using a thicker oil in a hotter climate. That's probably a good idea.

I'm also sure the RX8 couldn't tell a good mineral based "synthetic" like PP from regular old dino either. In fact, it probably would appreciate the upgraded protection PP would offer.

 

[rshunter]

Why mess around, just use the oils that are designed to deal with a rotary's issues. They've been proven in the heat of competition, having won LeMans...

Idemitsu Racing Rotary Engine Oil 10W-30 (Full Synthetic)

Idemitsu Racing Rotary Fuel Lube (Premix) - Synthetic Blend

 

[Spazdog]

I ran Castrol Syntec 5W50 in my old 12A '84 RX-7.

I never had any problems.

Granted that is a carbureted rotary with a hand operated choke without any of the RX-8's flooding issues. (which may be diluting the oil

)

 

[zoomzoom]

Originally Posted By: rshunter
Why mess around, just use the oils that are designed to deal with a rotary's issues. They've been proven in the heat of competition, having won LeMans...

Idemitsu Racing Rotary Engine Oil 10W-30 (Full Synthetic)

Idemitsu Racing Rotary Fuel Lube (Premix) - Synthetic Blend


so one could make case that redline would be a good oil for rotary?