Oil Change, Royal Purple
 

I just got back from my fathers shop, I got my first oil change for my Boxster. I used 15w-40...I know I'm suppose to use 15-50 but royal purple doesnt make it...I should be fine.

But already after 20 miles, Im reeping the benefits. The idle is getting smoother with every mile i drive, the acceleration is more crisp, smooth & a tad quicker.

I had the same results using this oil in my Twin Turbo but I stopped using it cause the price for the oil was to high, But nothing is too expensive for my Boxster.

My Idle is SOOOOOO much better, I figure after about 500 miles that the idle should be so smooth that I wont be able to tell the engine is running just like in my 140,000 mile Twin Turbo.



I've witness some pretty amazing stuff with this oil in the past, One of my buddies turned me on to this oil when he showed me a before and after picture of his head on his newer prelude...With normal oil the cams, valve springs & all metal surface that oil touched looked like any other car,

But after 3000 miles with Royal Purple in his engine, He took off the valve cover again to replace a cover gasket and it was remarkable...The cam, valve springs and everything under the valve cover looked polished and whatever blackish residue that was on the oil soaked parts was now gone...

Does anyone have any experience using Royal Purple gear oil for there manual trans?

Hi,

RP is good stuff, and for the price it better be. The same thing can be said for RedLine. They're both better than Penzoil, Gulf, Sunoco, Texaco, but so far as the engine is concerned, they're just on par with Mobil1, they're not some Mystery Elixer...

Happy Motoring!... Jim'99

It seems like everyone on here has used redline. I watch all kinds of car shows and they seem to like both equally. So either way you go it should be fine. Just make sure you dont change weights if your car has variocamplus or something. I've been reading that imagine auto forum and the weight of the oil is specific to how your variocam works and stuff like that. But I dont think your car has that.

Boggtown, our cars DO have variocam... they just don't have variocam plus, which is the new improved version. Did the threads discuss oil weight requirements of boxsters like ours with variocam, or was it the variocam plus only?

I had my oil changed at the dealership last Friday, in preparations for winter storage. I supplied my own oil. I brought 9 quarts of Red Line 5W40.

Hey thanks for repling to my thread, What weight would you recommend for gear oil on my 100,000 mile original transmission??? I think i want to go with Royal Purple brand also.

Use this link & chart:

http://www.royalpurple.com/techa/tranxref.html


I think you would use the Max Gear 75W90.

You are correct, i called the Royal Purple Co. and they told me 75w90 is the correct weight for my boxster.

"There are two sections to these tappets. The center section and the out edges. As computer deems necessary based on load, TPS, RPM etc the cams will switch from 3mm lift to 10 mm lift. If you look at the picture above you will notice the 3 sections to each lobe. This is the equivalent of 2 cams in one. The sections of the tappet will drop out exposing the desired section to achieve a specific lift. At the same time the cams are also advancing from the sprocket on the nose of the intake cams. It is a very elaborate system that relies on oil to act as a hydraulic coupler. This is what activates and moves these items. Never use anything other than the weight the factory recommends." (http://www.imagineauto.com/996TTbuild.htm)

I believe this is variocamplus, but I personaly dont know. I just play it safe and keep it at factory weight. The Porsche engineers know more than I do.

Does this apply to variocam plus only or both types?

Only $6/quart if you order 5 gallons at a time.

http://www.karlracing.com/html/motor_oil.html

That's actually cheaper than what I've seen in Mobil 1.

15-50 is too thick for your car.......Porsche recommends Mobil 1 0-40.

Here is a good (but long) read on motor oil written by a very knowledgable source.

Read it and you will learn a thing or two about motor oil, what the numbers mean

and why you want to use 0-40 for your porsche

http://63.240.161.99/motoroil/

isnt 0-40 for cold climates? Its warm here in Southern California almost year-round. I used 15-40.


BTW that very loud embarrasing lifter tapping i would get once the engine is cooled is now gone...Now i just have the normal 1 second tapping noise once the engine is cooled, which is pretty quiet.

no, 0-40 is not for cold climates. I would never use 15-50. It is much too thick, no matter where you are, or how hot is it outside.

read the articles in the link I gave below. Again, it is long, but if you can follow it, you will understand why 0-40 or even 0-30 is the better oil to use.

15-50 is needlessly increasing the amount of time that it takes the oil to reach operating temp at startup. This results in an increased time to achieve proper lubrication, and an increased time of extreme engine wear. All oils achieve the proper viscosity at operating temps.

The real variable is how long it takes the oil to get to proper temperature (i.e. to thin out) AT STARTUP.

the thicker the oil, the much, much longer it takes.

Anyway, on my boxster, there is a sticker on the trunk lid near the oil filler neck that clearly states "Use Mobil 1 0-40 ONLY"

The local dealership, "Niello Porsche" will only use Mobile 1 0-40,they will not touch anything else.

Hi,

Most Motor Oil is multi-viscosity and uses the 4 or 5-character description such as 10W40. The 1st number is the actual weight of the Base Stock of the Oil and is followed by a 'W' - the SAE's designation for Winter operating (cold start) conditions, the last 2 numbers are the viscosity of the Oil once it reaches a theoretical operating temperature - 150° F. These types of oils are classified as 'non-Newtonian' because of this ability. A common misconception is that these Oils are actually a blend of two different weight Oils, but this is not true at all.

Modern Oils contain an additive package which includes 'Viscosity Index Improvers'. These 'V.I. Improvers' help the Oil to do the opposite of what it wants to do when it warms up - which is to thin out. V.I.I.s contain long-chain polymers which are temperature sensitive. These polymers are molecules which 'curl-up' at lower temperatures allowing the Oil to flow at it's stated weight (the 1st number). At 150° F, these polymers 'uncurl' due to the temperature and essentially make the Oil thicker so that it now has the Viscosity (the resistance to flow), or Flow rate, which is equal to an Oil with the weight of the second number.

Because of this, you want an Oil which has the lowest weight such as a 0WX oil because this oil will circulate through a cold engine faster. Then, you want the Oil to behave like a thicker Oil once the engine warms up so you want a higher 2nd number such as XW40 or 50.

But, this system is not perfect. As counter-intuitive as it may sound, you do not want an Oil which is too thick. You should never use a 50 weight Oil in a Boxster. An XW50 Oil is 20% thicker (at operating temperature) than an XW40 Oil. This means that the engine has to work 20% harder just to move the oil around inside your engine. An engine with thicker Oil produces significantly less power, uses more fuel, produces more emissions and runs hotter, all contributing to shorter engine life. A thinner oil can more easily and quickly be 'pumped-up' to the critical parts of the engine, takes less energy to move it around, helps the engine to produce more power, less emissions, better MPG. And the engine will last longer.

Porsche has determined that 0W40 is the optimal Oil to use in the Boxster, anything more is actually not better at all and with it, you won't achieve the stated MPG or Power and consequently 0-60 times or Top Speed. Using a thicker 50weight Oil will cause greater wear sooner than sticking with the recommended 0W40.

Also, Porsche specifically recommends Mobil1, not merely a synthetic. This is not due to broad availability or some SweetHeart deal they have with Mobil Oil. Mobil1 is truly the best of all the synthetics. It is produced using the PAO method (meaning it is a true synthetic with no trace amounts of Sulphur or Phosphorus which Dino Oils contain, and which are very destructive to an engine). And, Mobil1 contains only 10%-12% addditives by volume (depending upon the type). Royal Purple and RedLine contain nearly twice as many additives by volume meaning that they actually contain less Base Stock Oil/volume, in other words, there's more Oil in Mobil1 than RedLine or Royal Purple. They're not necessarily awful, but they're not as good as Mobil1.

Hope this helps...

Happy Motoring!... Jim'99

That's still technically a Newtonian fluid.

does viscosity vs. temperature effect the classification as newtonian or non? isn't it shear / strain vs. viscosity? my fluid mech / tribology is rusty...

Hi,

Sorry, but I don't agree.

The shear stress of a petroleum oil or other Newtonian fluid at a given temperature varies directly with shear rate (velocity). The ratio between shear stress and shear rate is constant; this ratio is termed viscosity. The higher the viscosity of a Newtonian fluid, the greater the shear stress as a function of rate of shear.

In a non-Newtonian fluid -- such as a grease or a polymer-containing oil (e.g., multi-grade oil) -- shear stress is not proportional to the rate of shear. A non-Newtonian fluid may be said to have an apparent viscosity, a viscosity that holds only for the shear rate (and temperature) at which the viscosity is determined. The shear failure point in most oils is between 4,000 and 8,000 psi. Source - http://www.lemd.com/motorsport/previous.cfm?id=19

Newtonian fluid - a fluid with a constant viscosity at a given temperature regardless of the rate of shear. Single-grade oils are Newtonian fluids. Multigrade oils are NON-Newtonian fluids because viscosity varies with shear rate. Source - http://www.oilanalysis.com/dictionary/default.asp?definitionsearch=xqxqxqxq222&alphasear ch=N

Newtonian Flow - Occurs in a liquid system where the rate of shear is directly proportional to the shearing force, as with straight grade oils which do not contain a polymeric viscosity modifier. When rate of shear is not directly proportional to the shearing force, flow is non-Newtonian, as it is with oils containing viscosity modifiers. Source - http://www.chevron.com/products/prodserv/ehl/techterms.htm

I rest my case... ;)

Happy Motoring!... Jim'99

The specification of a Newtonian fluid is the linear relationship between shear and strain for any given temperature and pressure so the variation of viscosity with temperature (or pressure) is allowed for a Newtonian fluid.