i have a 2005 RS

what grade of oil should i be using


5w30
or
10w30

please answer quick

nevermind

im gonna use 5W30 royal purple

Either is fine as long as you do not go outside the recommended temperature range for the viscosity being used. Read the Oil FAQ-
http://forums.nasioc.com/forums/showthread.php?t=499177
Also look in your owners manual if you have one, there is a chart with recommended viscosities vs. expected ambient temperatures. This info is also on the Subaru website.

My Forester manual lists two oils for general driving. 5W30 is prefered with temperatures up to 100 degrees F. 10W30 for temps above 100. I drive in SW Florida where daily temps are at the very upper end of the 5W30 range so I use 10W30.

I heard that 5w30 is straight for normal driving conditions unless you live in a hot climate then 10w30 is prefered. Also if you beat the crap out of it like high revving and the like then you may want the thicker oil even if its not that hot out.

I'm in Florida too where it's summer pretty much year-round and I drive hard sometimes and make a lot of short trips so I use valvoline durablend 20w-50 in mine. I use straight 50 weight valvoline racing oil in my honda but it has a lot more miles than my Suby. The Honda is kinda rough on a cold startup but I didn't notice any rougher startup when I switched the Suby from 5w-30. With how far north you (the O.P.) live, that royal purple 5w-30 is probably a great choice especially for the winter.

5w30, I use penzoil!

My Forester manual lists two oils for general driving. 5W30 is prefered with temperatures up to 100 degrees F. 10W30 for temps above 100. I drive in SW Florida where daily temps are at the very upper end of the 5W30 range so I use 10W30.

I thought the numbers in the oil specification were :

"cold rating" W "hot rating".

This means that 5w30 and 10w30 should have similar properties at the
hot end, but the 5w30 will be 'thinner' at cold temperatures. 10w40
(or 5w40) would be a better choice for summer but I can't find it
anywhere in Mobil 1 form.

I, personally, think that ANY 5w30 is too thin for a turbo engine if it is driven hard AT ALL...even if you live above the arctic circle.

It seems to me that WAY too many people just don't use their heads, and have NO knowlege at all about oil and what it is and does in an engine and therefore use oil that is way too thin for driving conditions......if you drive in stop and go traffic----just about the worst possible thing to do to a car(and engine) 5w30---and even 10w30--- is too thin for ambient temperatures above freezing.

...go ahead, guys....pour that water thin crap in your engine.....go right ahead.......I know better.

It seems to me that WAY too many people just don't use their heads, and have NO knowlege at all about oil and what it is and does in an engine and therefore use oil that is way too thin for driving conditions......if you drive in stop and go traffic----just about the worst possible thing to do to a car(and engine) 5w30---and even 10w30--- is too thin for ambient temperatures above freezing.

Or, maybe, these people are just following the Owner's Manual with the recommended oil viscosities.

But, I agree, an xW30 oil is too thin for a car that is driven hard, and more so for a turbo.

I find it interesting that the hard driven Honda racing engines (Formula one) use Mobil1 5w30. That leads me to think that the factory engineers know more than some of us on this NG. If one looks at the visosity of many top end oils you will find the viscosity of 5w30 and 10w30 the same at high tempertures. It appears then that the 5w vs the 10w equates only to the cold engine. Now I expect someone will chime in with what about shearing down and that too only seems to apply to some selected oils.

I find it interesting that the hard driven Honda racing engines (Formula one) use Mobil1 5w30. That leads me to think that the factory engineers know more than some of us on this NG. If one looks at the visosity of many top end oils you will find the viscosity of 5w30 and 10w30 the same at high tempertures. It appears then that the 5w vs the 10w equates only to the cold engine. Now I expect someone will chime in with what about shearing down and that too only seems to apply to some selected oils.



:rolleyes: .....d00d....those engines are SPECIFICALLY BUILT FOR RACING.......WAKE THE HELL UP.

Or, maybe, these people are just following the Owner's Manual with the recommended oil viscosities.

But, I agree, an xW30 oil is too thin for a car that is driven hard, and more so for a turbo.


...the same owners manual that wants you to run your tires at 31/29 :rolleyes: or some such ridiculously low pressure????


...and the company that is trying to get their CAFE up so that they can avoid paying all sorts of 'penalties'???

WAKE UP people....you are being led around by the noses.....

The USDM is the ONLY market that 'recommends' 5w30 oil....and has such ridiculous BS parts on Subaru's that NO other market gets stuck with....

WAKE UP.....

I, personally, think that ANY 5w30 is too thin for a turbo engine if it is driven hard AT ALL...even if you live above the arctic circle.
While I generally agree with this statement, you need to consider that the "30" in Xw-30 is a range of viscosities and not a fixed value. Some brands (Mobil 1 springs to mind) run on the "thin" end of the 30-weight scale, while others (Castrol Syntec 0w-30..."German Castrol" or "GC") is on the "thick" end of the 30-weight scale and is almost a 40-weight. I have no problems at all recommending GC for use in a hard-driven STi. In fact I use it in my STi (UOA to come in another 4,000 miles).

I use 5W-20 is that too thin :confused:


























j/k I burned alot on Mobil 1 5W-30 and have switched to 10W-30 and all is well. I do drive it like its been naughty though.

I use 5W-20 is that too thin :confused:
Believe it or not, there is a Doctor (AEHaas) who posts on BITOG who uses Xw-20 in his vehicles...and he lives in Florida!

I am using 0W-20 and 5W-20 oils in my Ferrari, Maybach, MB SL 600 and Expedition here in Florida all year. UOA are good. Of course I am not on the track every day nor pulling trailers.

But he does know a lot about motor oil, check out his writing here:
http://63.240.161.99/motoroil/index.html

With that said, I don't have the cajones to run a Xw-20 in my STi.

Why do people even mention racing when talking about oil? How many race cars go for 3,750 or even 7,500 miles before changing the oil?
Why do people mention Porsche using Mobil1 when discussing synthetics (other thread)? Pssst, engine differences aside Porsche does not recommend Mobil1 30 weights. :D

Yes, it's a fact that 5W30 is "preferred" for fuel economy. Just read your owner's manual. Like Andy H mentioned, there are 30 weights that are in the upper range of the SAE's specification for a 30 weight and there are 30 weights that are very shear stable. You just need to do your research and find out what those oils are. Also, the better 30 weights have a high temp high shear rating of 3.5 or higher.

The best results I've seen in a WRX using Mobil1 30 weights is one that is driven a lot of highway miles every day (look around at BITOG).

Yes, people use 5W20 in high performance engines. Actually, a good number of people on nasioc are driving around with 20 weight because their oil has sheared down and they don't even know it. Right Andy? :D

-Dennis

Thanks for the heads up and the "WAKE THE HELL UP" Uncle S. God it must be wonderful feeling to be a self appointed expert/grease monkey that knows so much more than lubracation and machanical engineers

Thanks for the heads up and the "WAKE THE HELL UP" Uncle S. God it must be wonderful feeling to be a self appointed expert/grease monkey that knows so much more than lubracation and machanical engineers



WHAT....and let the rest of the Subaru word laugh at us for running water in the crankcase??? :lol: :lol: :lol: :rolleyes:


Man...If ya don't know jack, don't post....and don't try to mix god damned racing engines and their technology with street engines and don't try to mix manufacturers and their engine building practices 'cuz they don't mix and...............well if ya don't get the point...

The point of this is that most ordinary people wouldnt know the difference between engine oil and gear lube or brake fluid or coolant.......or what any of the specifications for each mean and why they are important.....so if you wanna fill us in on all the specifics, go right ahead......and keep putting 31/29 in the re92's and think thats just fine, too.

Thanks for the heads up and the "WAKE THE HELL UP" Uncle S. God it must be wonderful feeling to be a self appointed expert/grease monkey that knows so much more than lubracation and machanical engineers
FHI makes recommendations in N. American owner's manuals based on maintaining Corporate Average Fuel Economy requirements. This 5W30 discussion only happens in N. America even though Impreza's/Foresters are all built in the same place. For example, just spend some time at subaruforester.com (http://www.subaruforester.com/viewtopic.php?t=8855&highlight=oil) and check out the oil recommendations in the European forums.

Putting 5W30 in a new turbo engine at the factory for all of N. America is probably not what the FHI engineers had in mind. Otherwise, people in Texas wouldn't be driving around with a 20 weight after 1,100 miles on the factory fill oil like this guy:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002321
Blackstone:
"We put this oil in as a 5W30, but the viscosity was a little low, so it may have been a 5W20".

Most people don't look past the number on the oil cap (5W30), and see that they actually require a thicker oil for their location and driving conditions. My 97 OBS had this on the cap, as well as my FXT. Is 5W30 ideal for both cars in all conditions year 'round? No!

Back to the original question. :D Using a 10W30 in summer and a 5W30 in winter in Toronto in an RS is a safe bet (whether conventional or synthetic) in normal driving conditions. RP 5W30 (http://www.royalpurple.com/prodsa/rpmoa.html) is thicker than M1 5W30 at 100c, but I don't know how shear stable it is. There are some used oil analyses of the RP in a WRX on bobistheoilguy.com. Do a search there. :banana:

-Dennis

Thanks for a sensable responce Dennis and you didn't even need to curse or swear to get my attension. I will check the Forester site as you suggested. ed

Since it's a RS and you live in Toronto, I would suggest 5w-30 year around. You can also do 5w-30 winter and 10w-30 if you want. I don't think either route will make any difference. Use a good synthetic like Mobil 1 to ensure good winter starting performance during Toronto winter.

<From a fellow Canadian who lived in Vancouver who don't know what a real winter is =) >

The USDM is the ONLY market that 'recommends' 5w30 oil....and has such ridiculous BS parts on Subaru's that NO other market gets stuck with....


Scotty, are you sure?

I posted in the MRT Australia forum asking the WRX owners there and they said they had the same viscosity chart as us (5w-30/10w-30/10w-40).

I read the Japanese Impreza maintenance book and they put in 5w-30 in the oil change write-up/guide referring that weight to the factory recommended weight.

After all that, I personally use Mobil 1 10w-40 EP in my WRX... :devil:

I just want to point out that the US is not the only market with 5w-30 in the WRX. Maybe not on the oil cap with words like "recommended". But the oil recommendation chart are the same as Australia and Japan.

While I personally would not use 5w-30 in my car. I don't think using it will blow it up (unless you live in Las Vegas and drive 150mph down the highway in dead summer running dino oil with 7500 oil change interval)....

canada gets cold...5w30 or Full synth German Castrol 0w30.

Thanks for clearing that up with some facts Gunner. Always did like data over personel opinions. ed

Scotty, are you sure?

I posted in the MRT Australia forum asking the WRX owners there and they said they had the same viscosity chart as us (5w-30/10w-30/10w-40).

I read the Japanese Impreza maintenance book and they put in 5w-30 in the oil change write-up/guide referring that weight to the factory recommended weight.

After all that, I personally use Mobil 1 10w-40 EP in my WRX... :devil:

I just want to point out that the US is not the only market with 5w-30 in the WRX. Maybe not on the oil cap with words like "recommended". But the oil recommendation chart are the same as Australia and Japan.

While I personally would not use 5w-30 in my car. I don't think using it will blow it up (unless you live in Las Vegas and drive 150mph down the highway in dead summer running dino oil with 7500 oil change interval)....


..... having a 5w30 oil on the 'chart' does not make it a good idea or make it 'recommended'....just useable for a certain temperature range.....and 5w30 M1 specifically is too damned thin for any but the coldest climates, regardless of what some of the idiots, here, think.

Thanks for clearing that up with some facts Gunner. Always did like data over personel opinions. ed



....d00d....you are a prime example of someone that has no training or education in anything related and is just wanting to believe SO BADLY in something that you are blind to facts.....glad I'm not as....well...not like you.

My personal opinion is based on professional experience and actual training....so go blow yourself.

I was just pointing out that the fact that you were wrong that only the US recommends 5w-30 for the WRX (or put it on the viscosity chart, whichever way you want to refer it to).

..... having a 5w30 oil on the 'chart' does not make it a good idea or make it 'recommended'....just useable for a certain temperature range.....and 5w30 M1 specifically is too damned thin for any but the coldest climates, regardless of what some of the idiots, here, think.

I was just pointing out that the fact that you were wrong that only the US recommends 5w-30 for the WRX (or put it on the viscosity chart, whichever way you want to refer it to).


Then that information is new(er)....it was not in the literature that I researched.

Thanks again Gunner for some RELIABLE information. ed

I read the Japanese Impreza maintenance book and they put in 5w-30 in the oil change write-up/guide referring that weight to the factory recommended weight.

Which Impreza book? I doubt you will find 5W30 being the preferred weight in every Subaru, like in N. America.

-Dennis

The Impreza maintenance book published by HyperRev.

Which Impreza book? I doubt you will find 5W30 being the preferred weight in every Subaru, like in N. America.

-Dennis