9krpmrx8

iTrader: (46)

I wanna know.

Flashwing

So I would like to point out that when I come across information that differs from either my point of view and or corrects something I said I will always ensure I make such a correction.

So,

I happened to be cruising to work today and noticed that my pressure at about 3300 RPMs was around 60psi to 62psi. This was around 180 degrees of oil temperature as well. It would vary between 175 to 180 depending on the driving.

So, the question I have regarding the factory pressure reading that someone posted would be this.

Is the pressure that was listed of IIRC 57psi @ 3,000 RPMS a minimum value or the suggested value? Mazda should have an understanding of what the ideal pressure should be for proper lubrication.

If the listed pressure is a suggested value then the 20w was pretty close. If it's a minimum value then that would pose a problem for higher temperatures.

nycgps

iTrader: (1)

Its Mazda's "reference" point. they didnt say if its minimum or whatever.

that simply means you "should" get it if your car is running normally (and using the right oil)

I think Im getting there, 93 degrees today + stuck in NYC bumper to bumper traffic + its all tarmac covered roads = super duper hot oil temp. hmm, it went up to 108 Celsius, but when I start moving, it got back down to around 101 and traffic just stopped. so I rev it to 3K, Im getting that pressure +/- maybe 5 psi (cuz it jumps up and down cuz A/C is on)

Flashwing

Thanks for the info. I guess the ideal would be to find a weight your happy with that hopefully would remain around those values.

nycgps

iTrader: (1)

*sigh*

another n00b

can you please search ...

in short, YES YOU CAN USE SYNTHETIC. THEY SELL SYNTHETIC IN JAPAN FOR ROTARY ENGINES. YES FROM MAZDA THEMSELVES ! So YES GO FUXK THEMSELVES WITH AND THEIR BULLSHIT USING SYNTHETIC OIL COULD WORSEN BLAHBLAH BLAH

and for the record, to get 5w20 oil grade, it HAS TO HAVE some sort of "evil synthetic" in the mix. so yeah MNAO failed again.

onefatsurfer

So, there's a mobil 1 rebate for $10, and Costco sells 15w50 synth. So, 15w50 synthetic is what I'll be using. 6 quarts for $12 after rebate

Brettus

iTrader: (2)

A poor choice IMO . Never mind - it will probably still be OK .

olddragger

iTrader: (3)

i wonder what is happening with our cars? ga cars are so relaxed that we get lower pressures-- stumps me.
Flash have you ever tried 40w and noticed the pressures?

Flashwing

Honestly I cannot recall pressures with the 40w as I was running that before I really started paying attention to that stuff. Up until now, my pressure gauge's only purpose in life was to let me know if I just dumped all my oil out of my motor!

The one thing to keep in mind is if the relief valve bypasses oil from the filter back into the engine to keep the pressure under control then running high pressures could result in less proper filtering of the oil.

If that's the case, it's even more important to run an oil which fits your circumstances. If you know your track sessions will cause your oil temps to remain high then running a higher viscosity oil will help keep those pressures and flow rates around what a lower viscosity oil would at lower temperatures.

LionZoo

Nobody is forgetting about base stock. It was merely a reminder that mineral oils have detergents as well and so a quality mineral oil can clean out deposits just like a synthetic oil can. The rate is obviously up for debate, but the cleaning action is there.

Nobody is slagging synthetics so relax. We know their advantages.

LionZoo

Oh no, not the New England accent! As if I don't hear it enough here. Spare me!

9krpmrx8

iTrader: (46)

Okay so oil pressure gauge is in. I filled up with Shell 93 octane, drove home 160.6 miles and filled back up with 7.17 gallons. So 22.3 MPG Highway miles on a brand new engine, BHR Coils, wires, plugs. No big deal though because she pulls like never before.

Anyway it was and average of 105 degrees the whole way back to San Antonio. At about 75-85PMH between 3-4k depending on speed the oil pressure was pretty consistently at 63-70PSI.

olddragger

iTrader: (3)

Ga cars are just low pressure cars then--not being smart now. Just must be something we are doing different ---another mystery yee haaa!
Anyway its a mute point i guess because i dont no of anyone that is still running 5/20 in Ga.
I am sure some are out there--i just dont know them.
Hell--our top pressures were only 80 somthing.
I wonder if our tachs are off?
olddragger

9krpmrx8

iTrader: (46)

Weird I took her up to red line and my pressures were almost 100PSI. At idle I'm at like 20PSI. But even this morning on the way to work fully warmed up (Now I always let my car get fully warmed up now before leaving the house) at 3k @70MPH I was at like 65PSI.

I am curious to see what happens to my pressures at the oil gets older.

syntheticdarkness

iTrader: (7)

Is that with 0w30? So far we have 20w, and I believe 30w, need some more weights. Lots a great info in this like said before, and only getting better. Someone should take all the results and make a list on here side by side so we all can see the different psi etc...

Spin9k

yes, break out your data recorder, do some periods at specific dash indicated RPMs and see.

9krpmrx8

iTrader: (46)

Yes, its with Castrol Syntec 0W30. I've been paying close attention and at cold idle (still over 100 freakin' degrees outside) I'm at 20psi but when she is fully warmed I'm at 30 PSI. At 3k I'm at closer to 70PSI pretty consistently.

9krpmrx8

iTrader: (46)

Okay here are my numbers for today so far running a few errands. Sometimes the car seems to be off about 10psi for no apparent reason. I will keep an eye on it.



Gotta get the oil temp gauge in to get some more real data.

olddragger

iTrader: (3)

i just doubled checked with some ga buddies and with 20/50w they are getting between 60 and 70 lbs at 3K by our tachs. I knew i wasnt crazy---close but not there yet
another at idle with 10/40w? His is at 10lbs.
Max at 9K is 80.
3 different cars are showing the same and oil temps are at 180F


go figure?????????????????
Od

Flashwing

The actual climate has very little to do with overall engine operation. This is why the myth of needing two types of oils for summer and winter is false.

Your motor is going to always operate at 180 degrees or higher so that much is the same with everyone. I don't know the weather in Ga. but between July and September the average temp doesn't drop below 100 degrees during the day here.

I'm kind of surprised so many RX8 owners out there are running pressure gauges. That seems to be a rather rare thing out this way.

9krpmrx8

iTrader: (46)

So flash what do you think about the pressure fluctuations? I will be installing my Oil Temp gauge soon too.

Flashwing

I don't have a ton of my own data to compare it to so much of it has been what I've noticed just driving around. From what I can tell the pressure you are seeing is pretty close to what I've seen myself. If you're running 0w-30 castrol then that would follow as well. The operational temperature viscosity of most weights are close together but the German castrol is a thicker 30w so it's on the upper part of the range.

Your intake air temps give an idea of what the ambient temperature was give or take a few degrees. My AEM is about 8 degrees warmer than ambient nearly all times. The factory airbox should be similar.

The pressure behaves as expected in that it drops as your coolant temps increase. It's hard to say what specific reasons would cause your pressure to be different at the same RPMs.

Honestly I think we can overanalyze this and I'd stick to a more general view of oil pressures. Clearly you can use them to determine if you need to look into changing the weight of your oil. If you are seeing high pressures across all ranges then you might be running oil that is too thick for your operational temps. If the pressures are too low then the oil is too thin.

9krpmrx8

iTrader: (46)

What is considered a low pressure?

Flashwing

I imagine anything that is below the factory listing of 57 PSI at 3,000 RPMs.

9krpmrx8

iTrader: (46)

Good stuff. I'm so curious to see what my temps are when its 109 degrees outside in traffic. WTF can't Mazda just add a oil pressure sensor and temp sensor to the ECU so my Scangauge can read it.