Let me get home and tell you in a few days. I just want todouble check that those specs in psi were not fudged by your dealer. Give me a few days.

 

kind of makes me wanna get a compression test done. :P

 

I just did a bit of research, the min PSI at 250 rpms is 98.6psi, and the max is 120psi. So it seems im ok. But none the less, Ill still take you for a ride one day for that noise issue. No idea what to listen for.

 

Check the UOA section. The 10w30s are shearing into 20wt range with the exception of the HDEO 10w30s which start out higher. Even the 1 M1 10w30 sheared to the 20wt range as did the RP 5w30 and RL 30wt blend. None of the 20wts sheared to 5wt and the most shear stable oil so far has been Valvoline 5w30 which is sold as a mineral oil and from its price point is likely at least 50% group II or II+. With regard to a racing wt oil dont forget about hydrodynamics where the viscosity will be re-enforced by the higher pressures associated with the application and the need for additional viscosity makes more sense in the lower speed street apps. Finally, most familiar with engine oil life cycles will probably tell you that your viscosity loss stabalizes at around 1000 miles so from the UOAs we have here 10w30 versus 5w20 appears to make no material difference in protection from viscosity.

 

^ Good points, and I stand corrected....if I get what you're saying.... as what you say shows the different formulations recipes oil makers use to achieve desired results or even similar results. Those UOAs show oils w/ a strategy of starting out w/ mid base weight stock with cold-flow modifiers (to achieve the low W spec) and hot modifiers (to extend protection to hot range). Actually a good strategy to protect the engine from peps who don't change oil religiously and/or for extended oil change intervals, as the oil never reaches it low W-spec no matter what. Oil formulation certainly is part art, part science. The single oil spec number on the can says nothing about how an oil evolves over its design life - I guess that's the untold story UOAs help shed light on for us to ponder.

 

About theses Used oil Analysis' (UOA) where oil viscosities are showing a drop down to the next grade, at what mileage are these being done at? I change mine after 4000km, and if I put in 5W30 only to have it lose viscosity down to 5W20 by 4000 km, I should be fine.

 

Mike, that was 2 years ago you did compression test..
2 years ago my engine was fine too

 

ROtary_RX8...

tell tale signs if you should be doing a compression or not...

1) significant drop in fuel economy.
2) strange rattling noises after long drive in the upper rpm
3) loss of power after a long drive, plus rough sounding idle
4) takes longer to start the car (verify that battery/starter are good), and car just takes awhile to catch on ignition


If you don't have these, dpn't worry too much about it.

 

I saw significant drops in viscosity on my tests with Castrol 0W-30 and the factory fill 5W-20. I usually change mine every 3,000 miles or less. Mobil1 0W-40 has held up very well in my tests and other members test so I am sticking with it. But of course your driving conditions affect how your oil stands up. You can read the UOA thread for details.

 

I'd posted this somewhere before, but this should answer your question as it has come up before. So basically before I bought the stuff I wrote to Idemitsu for the answers to some questions I and others had about their "Racing" oil, i.e., the questions are mine, the answers are Idemitsu's. BTW I just use their products, have nothing else to do w/them.


Take aways are:

1. unlike 5W-20 Mazda recommends, this does not meet Federal fuel efficiency stds
2. 10w-30 (and obviously 20W-50) not for use during (really) cold weather
3. otherwise, use as a normal oil

 

Castrol GTX 5W30 conventional + Idemitsu premix 8oz per tank + 4000km oil changes..

Q.E.D.

 

Ive seen the word WOT used several times. What is it?

 

W-ide
O-pen
T-hrottle

 

WOT means wide open throttle

Im soooo happy with my mobil1 0w40, 15w50, rp 10w40, redline 20w50.w00t

Except that right now my car gets the p2096 and p0171. The front o2 sensor probably failed.no time to check yet. Car drives fine no issues. Meh. This car is weird.

 

IE "Pedal to the metal".

In super layman's terms foot down with accelerator pedal below foot.

I thought we all decided that oil was not a factor int he engines demise? Why are we still discussing oil weight?

 

Because oil, being so mysterious, is always fun to talk about?

 

Just got back from the dealership, had the engine block out of the car. PICS AND VIDEOS to follow

Had a chat with mechanic and I inspected the intake/exhaust ports/SSV/VDI. I must say, WOW I did a pretty good job maintaining the car. Intake is very clean. SSV and VDI are clean too, very little carbon buildup. No stuck SSV or VDI, all move very freely, no caked on carbon. Just fuel/oil mixture which is normal for port injection.

There is one area I am concerned with and that is the exhaust port. I don't know if it's supposed to be smooth or not, but there appears to be a 3-4mm thick ring of carbon that is forming right around exhaust port. Funny thing is, it's formed such that it's flush with where the edge of the rotor housing and the side plate piece meet, is this even normal? Pics and video are both hard to see, but I saw it and felt it with my finger poking in. It's HARD.

OMP injectors are fine, and OMP lines are clear. The mechanic said there was absolutely NOTHING I COULD HAVE DONE DIFFERENTLY to prevent the engine failure; at least it made me feel a lot better.

The reman unit came with a brand new flywheel, new thermostat, and new waterpump assembly.

BTW, random fact... QSEA-11-500A Mazdaspeed Lightweight FLywheel is officially discontinued part with none in Canada/USA. It is available on special order for a whopping $1200 CAD!!!!

PICS and VIDEOS to follow later.

OH also BTW... for anyone in the GTA area interested in the CX-5, Avante Mazda has one now. Just arrived today, and I saw it being moved around in the parking lot! WOOT WOOT! They said it will be ready for test drive by tomorrow or Friday!

 

The hard carbon buildup is fairly normal, I had to use a die grinder to remove mine.

That same hard carbon gets all over everything, in seal grooves on rotor faces everywhere.

 

Wouldn't that hard carbon eventually thicken and make the exhaust port smaller and smaller until its plugged? I see no way in hell seafoam or anything can possibly melt that **** off

 

Seems like its a good idea to get a Mazda Engine clean every 15,000kms to try and prevent this oil from building up and hardening.

 

Mike, your dealership DID NOT fudge those numbers (range of acceptable) on the right side. I have confirmed the following in 3 different units. The acceptable range of compression @ 250 RPM as follows:

KPA:
830 standard
680 minimum
150 diff / chamber
100 diff / rotors

Kg F / cm^2:
8.5 standard
6.9 minimum
1.5 diff / chamber
1 diff / rotors

PSI:
120 standard
98.6 minimum
21.8 diff / chamber
14.5 diff / rotors

Remember values need to be normalized for 250 rpm.

 

Those carbon is pretty normal.

And ur random fact is wrong. I can sell u the mazdaspeed which is really exedy flywheel right now for 750 bux shipped to canada :-) i have one for myself cuz i have been storing parts. It comes with counter weight and bolts for install. U want it? Paypal me the said amount in cash and i will send it to u tomorrow lol

Oooh u said does mazda still have them? Oh yes they do they still have quite a lot in their warehouse :-)

 

Forgot to add, the only thigs thats nla in the north america market right now is the mazdaspeed shift **** and mazdaspeed fog light kit for their bumper. If u want those u have to get them from japan.

 

Just going by what the Canadian system says nycgps.... I didn't make it up. Good for you for having it onsale. Why don't you go post it in for sale forum?

 

Why does mine show at 270rpms?