Hello all,

After reading multiple threads on these issues, I want to be sure I am doing the right thing.
1) I have been using Royal Purple 5w-30 for my last two oil changes. Any issues with this oil? It gets a lot of good "press".
2) I have 64K miles on the car, drive over 95% highway with occaisonal "spirited" driving. I think the factory 12,500 miles between is a bit out of my comfort zone, so I change the oil every 7,500 to 8,000 miles. With the way I drive, does this seem reasonable?

Thanks for your input.

 

Sounds like you're doing just right!

 

You are doing good my friend. I change mine between 5,000 to 7,000 miles with hard driving. And there's nothing wrong with Royal Purple oil. I use Castrol Syntec 5W-30, but that's just my personal preference.

 

Here are several links under oil that may help.

 

I use Royal Purple also, I change my oil every 5K miles as well. I don't see the need to change it every 3K as I don't autoX or drive it hard. Royal Purple FTW.

 

I previously used Royal Purple with no problems. I had been changing my oil every 5,000 miles but I am going to start changing every 7,500 miles.
I now use ELF oil because I get the oil change kit from ToeOut Performance in Arroyo Grande. Comes with Oil, Filter, Drain Plug, and Fuel Injector Cleaner for $48.
http://www.toeoutperformance.com/aft...spx?prod=13323
I also found it hard to consistently find royal purple in Santa Maria so I switched.

 

I use Mobil 1 and split the 15k interval, too - about 7500 miles or so.

 

Sounds like you are doing good.
I use Royal Purple 5-30 and change every 5,000 mostly because it is easy to remember. Probably over-kill but it gives me peace of mind.

 

www.blackstone-labs.com

You can order a sample kit from those guys and have them analyze your oil for you for 20-30 dollars. Certainly worth it to me, I had ran my oil for a year over the course of 5500 miles consisting of many short trips where the engine never really warmed up. The analysis came back fine, so I know I dont have anything seriously wrong despite that abuse.

 

In my travels, I came across a very interesting study done on oil type vs. wear. Needless to say, I will get RP whenever possible:

http://bmwchannel.com/eric/Oil%20Tests.pdf

 

Do you know when that report was made? It seems kinda old, and if that is the case most of the formulations have probably changed by now.

 

No I don't, and that is a very good point. I don't know if they would change drastically enough for me to actually want to put Mobil 1 in my car again, but it's definitely worth considering. However, I don't particularly like assuming that the company has fixed anything, so until then I think I'm sticking with RP!

FWIW, the last time I bought RP (late 2008), it came out to be about 8 bucks more for an entire engine full of oil (7 qts), so it's definitely not as cost prohibitive as sometimes portrayed.

 

$8?!? That isnt a typo is it? Agree though, I am sticking with RP for the time being.

 

mobil 1 every 10k. (it's good enough for porsche so...)

 

Plus, the "study" described in that article is seriously flawed, bordering on worthless.

The Timken bearing test used in the article only measures one narrow aspect of an oil's performance (specifically, extreme-pressure performance). There was no attempt in the article to compare the pressure levels in an actual engine to the pressures you can achieve with the Timken machine, which are huge.

Also, the authors said that they were using the Timken test (which takes less than a minute) to simulate thousands of miles of oil wear in an engine. That's like trying to predict how a windshield will stand up to years of abuse from sand and gravel by hurling a cinderblock at it.

One short-duration, high-stress event can't be used to predict the results of long-term, lower-level stress.

 

OK, I'm pretty **** on car stuff, but comparing the effectiveness of synthetic oils kinda sounds like discussing which type of quality California red can get you drunk faster.

While there are differences, given regularly-maintained cars (oil changed regularly, as we're discussing) are they significant enough to matter - really - in a street car? If a quality engine can generate great power and last 150+ thousand miles on regularly changed dino oil... yes, synth is better, but isn't this "degrees of perfection"?

 

The study definitely has it's assumptions... you can't expect a perfectly realistic test from anything other than taking brand new engines and running each under exactly the same rpm's, loads, duration, etc.

It is a relative test. That's the key point that should be taken out of this. It simply compares the lubricating ability of many different oils in a controlled environment. The study did make assumptions as to how the Timken test could be translated to the real world which I don't necessarily agree with, but that's not the point. The point is that in exactly the same conditions, some oils were able to lubricate the bearing MUCH better than others, and should not be taken as anything more. If you were looking for how long is oil should last, for example, this is not the proper test.

Personally, if I had to choose an oil, I would choose the one which withstands the highest load before it starts scarring my engine internals. You can take from it what you will, but I thought it was an adequate for choosing the oil in our road cars.

 

Nope, that was correct!

http://www.corvetteguys.com/royalpur...edium=Shopping

 

I think that article was more an evaluation of the various oils' extreme pressure (EP) additive package than anything else, and for the most part, an oil's EP characteristics don't come into play unless something has gone horribly wrong inside the engine.

Specifically, look at the Timken machine they used for the test. Unlike the bearings in a car, the oil isn't being forced under pressure between the two metal surfaces - the lower half of the Timken machine's rotating wheel is just sitting in an oil bath, which wets the surface of the wheel. In essence, the test is simulating what might happen if you had a *complete failure* of the car's oil system to deliver pressurized oil to the bearings.

DixonL2 mentioned "degrees of perfection", which is a good description of what's going on here, except that I would have called it "degrees of overkill". If the maximum bearing pressures in an engine never go above 900 PSI, Does it *really* matter if oil "A" can withstand 295,000 PSI while oil "B" can 'only' withstand 9,000 PSI? But I guarantee you that there are chuckleheads out there that read the article and are using it to argue that oil "A" is superior to oil "B" based on the test results.

That's what I meant when I complained that the authors never even made an effort to compare the pressures they were measuring to the pressures you'd actually see in a real engine.

Of course, it might have made for a boring story if they had said "We tested 18 oils and found out that all of them will easily stand up to the highest bearing pressures you're ever going to see in your engine".

 

+1 on corvetteguys.com They have the best price on 5w30 RP and deliver quick.

 

I go with Mobil 1 synth 5w30, and although I may get heat for it, I change it every 3k. Just the way I was raised. Look, I know the oil can last longer than that, but it is not ONLY degraded oil your taking care of when you change your oil, it's also all the muck and debree that floats in the oil. I change at 3k and my oil is no where near clean. just my 2c.

did I read correctly someone put 7-8 quarts in their engine? That seems high...

 

This is XSMINI's 2002 R53 S. Take a look at his valve cover after 180K miles and following the OBC oil change intervals. No sludge, no power loss, no problems.

You decide for yourself....



This is one of XSMINI's posts:
change when the OBC tells me! I currently have 179,4xx on the odometer, don't burn any oil, have had both the valve cover and the oil pan off, and there is no build up of any sort.

Change as often as you wish, its for your piece of mind. I know I sleep fine seeing what I've seen on mine.

Nik

He currently has over 191K miles on his MINI. The post original date was August 18, 2008.

 

No complaints from me with you changing at 3k. Better safe than sorry.

However, you may want to use Mobil 1 0w40 as it is a full syn. A little more expensive but much better protection.

 

the Mobil 1 5w30 I buy states that it is fully synthetic, is this not true? also, any comments about that 7-8ltr fill up?

 

Nope, not full syn. By definition yes but only Group IV.
Mobil 1 is a Group IV for most, 0w40 is Group V (as is Royal Purple and Red Line).

MINI fill is 5 ltr.

From the source of all knowledge, Wikipedia.

Synthetic Base Stocks

Synthetic motor oils have been made from the following classes of lubricants

• Polyalphaolefin (PAO) = American Petroleum Institute (API) Group IV base oil
• Synthetic esters, etc = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, polyglycols etc.)