george thomas

I spoke with Ken Shepard from technical dept Mazda Australia 2 days ago and he confirmed that the oil I had purchased ,Castrol type R synthetic 5w-30 was fine to use at my 1000 km service .Seeking further confirmation, I spoke with City Mazda Melbourne and before telling them about castrol type R, they told me that they use castrol Type R 5w-30 on their rx8's.
Had the oil changed yesterday at Albury Mazda where I reside.
Verdict: Car definitely runs smoother andseems to have a little bit more power.
Any thoughts?

takahashi

I think it is time for me to check my oil level. Nearly 3000km. First let me buy that Castro Type R.. how much are they?

rx8power

Whoa, that's strange coming from the mazda dealer. I've been working with rotary engine for 9 years now, and the reason people use synthetic oil in a regular piston engine is because the oil will take a great amount of heat and will not burn as quick as regular petro base oil. NOW, the reason rotary engines burn so much oil is because is mix with the fuel (kind of like a 2 cycle engine) to lubricate the internal parts like the apex seals. With synthetic oil it will be harder to ignite the fuel charge going into the rotor chamber.

Now, as far as I know the renesis still have a metering pump to send oil to the intake manifold. Please correct me if I'm wrong. That's why a lot of people don't suggest Synthetic.

But, since is coming from the Big Dogs at Mazda, I guess is OK. Anyways, they are the ones with that big "Mazda Certified Technician" patch on their shoulders. :D

Hope they are right!

Later

RX8Power

george thomas

castrol type R 5w-30 is a hydrocracked "synthetic" oil meaning that it starts out as a mineral base and is highly refined using hydrocracked technology to vastly improve its performance.
It's flashpoint for burning is below that of "fully synthetic" oils which use PAO base ie non mineral, thus making it acceptable for the renesis engine

This is my understanding

labrat

OK, George, let me see if I have my head around this correctly:

- "Normal" (non-synthetic) oils are produced during the fractionation (distillation) of crude oil. I guess they have a fairly wide spectrum of hydrocarbon chain lengths, and chemical species.

- "Synthetics" of the Castrol Type R are produced by hydrocracking of heavy crude fractions (reaction with hydrogen in the presence of a catalyst) and subsequent fractionation. I guess it is possible to have better control over chain length and chemical properties. From what very little I understand about the petroleum industry, hydrocracking is a way of making higher value added products from what would be fairly grotty tarry left-over crap

- "Full Synthetics" are made with PAO (Poly Alpha Olefins) starting with small unsaturated molecules. I guess it is possible to do all sorts of interesting stuff chemically to precisely tune the lubricating properties of the oil. From what I have seen on the web, Mobil 1 belongs to this class.

I guess what concerns forum members is that they use a high quality oil which does the best possible job in lubricating the renesis, but nonetheless is completely combusted in the motor so that there is no build up of difficult to combust residue which may affect operation of the seals or ports in the motor. My reading (subject to your correction) is that Castrol Type R would seem to be almost ideal, since the oil would be composed of pretty well saturated hydrocarbons, and would combust completely.

DMRH

Up until now, I have believed the (semi) experts & not used a full synthetic in any of my RX's.

For this matter I have been using the Penziol semi-synthetic as its easily available, well priced & worthy.

This is the first time that a laymens view of the technical reasons has been presented. I am well impressed & will now be searching for the Castrol Type-R

If anyone knows better, let them have their say......... REgards

Hymee

iTrader: (1)

My brother-in-law works for BP. Before his current posting (Director of BP Marine), he was world-wide sales manager for the BP synthetic base product.

He was somewhat miffed when I spoke to him about the arguments for/against synthetic oils. His explanation to me is that a synthetic oil is still a hydrocarbon chain, like the "real thing", but made in a chemical factory, rather that dug up and distilled.

I explained to him how the RE uses oil to cool the rotors. He thought a synthetic oil was better suited to that job because of it's higher heat tolerance.

I also mentioned the oil bening fed into the induction, and he did not think there was any problems with it being "burnt".

BTW - He was please to see the Castrol sticker on my car after the service. I just let the Manufactures Authorised Agent put in the oil that they see fit, and will honor the warantee (Castrol R 5W30)

Like I have said a few times - there are more myths about oils than about sex.

Cheers,
Hymee.

Wildcard

Just to clarify, it's called Castrol FORMULA-R 5w-30. I've been using it for the last 10,000km. A 5 litre bottle was about $45 from Super-Cheap if I recall.

If only it were 'type-R', then just like a Honda, you could add 20hp to the car just by putting a type-R sticker on it!

pricer01

Just visited Local dealer (McGraths Liverpool) this morning for a pre trip top up. Great service !!
Castrol Type R is what they use and they dont sell retail but happily topped me up gratis!!!!

They still claim to be waiting for the official Mazda RX8 oil.

Re the synthetic vs mineral debate (and I'm a banker so have no idea at all) its interesting that the manual doesnt specify one or the other. Given our consumer orientated economy, I'd have thought that it would be specified if it made a material difference.

Rob

timbo

I understand there has been an advisory to dealers from Mazda Australia on this topic. Can anyone obtain a copy?

Wildcard

I asked the guys at Grand Prix Mazda in BNE after my 10K service the other day what oil they used, and the service guy wrote this down on a piece of paper for me:

CASTROL TQF SOFTEC 5w30

dbb

BTW, Castrol type R and Penzoil Mineral 5w-30 are both available at Repco stores.