What oil would you recommend (ctxt!) - 986 Forum - The Community for Porsche Boxster & Cayman Owners

porschedude · 01-17-2007, 10:23 AM

I use 10W30 Mobil 1 in Texas. I think 10W40 or 0W40 will be fine too. Yes, Porsche recommends Mobil 1 but I think other brands are fine too.

FrayAdjacent · 01-17-2007, 10:33 AM

Well, I'd check into Amsoil, but for this change, I'm going to have to go with something locally available. Walmart has a ton of Mobil One.

Maybe later in the year for the next oil change, I'll look into something like Amsoil.

(used Amsoil once in my previous car... it was great oil! The first tank of gas after the oil change rated about 4mpg more than the previous tank, under similar conditions. It went back down to average over a few tanks, tho)

UroTrash · 01-17-2007, 12:54 PM

Fray, don't be fooled by what it says in your owner's manual.

As noted above Porsche has changed their minds about viscosities in cars old and new (well, at least liquid cooled cars) and now recommends the Zero-W40 for all of them despite the data in the owner's manual..

CJ_Boxster · 01-17-2007, 01:14 PM

I have a question, and its pretty stupid... Is 40 Weight the same as 0-w40?

UroTrash · 01-17-2007, 01:28 PM

Quote:

Originally Posted by CJ_Boxster

I have a question, and its pretty stupid... Is 40 Weight the same as 0-w40?

No Far from it.

Straight 40 weight is really really thick when its cold. 0-w40 flows like "zero" (actually not exactly zero, but close) when cold, and acts like 40 when hot. A true miracle of nature that.

CJ_Boxster · 01-17-2007, 01:33 PM

I just got off the phone with Royal Purple, while i know they dont have 0-W40, I asked if there was a way I can leave a message or suggestion of making a 0-W40 for Porsche Boxsters and they said that they are already developing that weight cause there are alot of desiels and clean cars that use 0 weights for emissions, So soon we shall have 0-w40 from Royal Purple.

Right now Im using Royal Purple 5-W50 which is bad.... but the car does run much better than it with the correct weight of mobile oil. I've used the correct weights in my other cars i've had and that oil is nothing short of amazing... i mean it litterally polished my cams and bearings on my 1967 mustangs and 300zx TwinTurbos.

I just cant wait for the correct weight from RP!!!! I'll soon change my gear oil and will use the Royal Purple brand, especially since i have 103,000 miles on the syncros.

MNBoxster · 01-17-2007, 01:55 PM

Quote:

Originally Posted by CJ_Boxster

I have a question, and its pretty stupid... Is 40 Weight the same as 0-w40?

Hi,

No, it's not the same. Multi-weight, or Multi-viscosity Oils contain long-chain molecules called polymers. At cold temperatures, the polymers are coiled up which allow the oil to flow as an Oil with the 1st number (W) weight.

But, when the oil warms up, the polymers unwind into long chains that prevent the oil from thinning as much as it would otherwise. The result is that at 100° C, the oil will thin as much as the higher viscosity number indicates. Another way of looking at multi-viscosity oil is to think of a 0W-40 as a 0 weight oil that will not thin more than a 40 weight would when hot. Hope this Helps...

Happy Motoring!... Jim'99

CJ_Boxster · 01-17-2007, 02:07 PM

it does, thanks jim

MNBoxster · 01-17-2007, 02:12 PM

Hi,

Oil is one of those things where Better is really only better if you have the need, or can actually use the advantage(s), one oil has over another.

For a Street driven Boxster, Mobil 1 is more than adequate. Is it as good as Royal Purple, Red Line or Amsoil? There can be measurable differences in the Lab, which are either not present in real life, or unnecessary.

If a car engine can go 300k mi. on Red Line without excessive wear, using Mobil may be just as good for 298k mi. with the same result. But, if the Red Line (or other premium brands) cost 10%-20% more than Mobil 1, then there is probably no positive cost/benefit to using it.

If you're racing the car, the premium oils may have advantages which you will actually realize, such as high-temp performance and such. But, again, in a street car, you'll probably never need, or realize, these advantages.

The one thing to realize is that you're never going to hurt the car using Mobil 1, it's a very good Oil. And, you probably won't forestall any breakdown or reduce repair costs when using any of the premiums over Mobil 1 either, it'll just cost you more.

The key is proper change intervals, and from all the research, this appears to be between 7500 and 10k mi. Porsche says longer, but their interval was established as much with Marketing in mind as actual testing. Also, the Porsche interval is qualified to be under ideal driving conditions which almost no one encounters. Your region's avg. temps, the environment in your area (such as Dusty - anyone regularly using the Expressway falls into this category), and your driving style can all reduce the recommended change interval. Hope this helps...

Happy Motoring!... Jim'99

CJ_Boxster · 01-17-2007, 02:32 PM

Thats true, but i like havin peice of mind knowing that I've experienced better results with RP over Mobile1 and that since i opted for Royal Purple, i have more peice of mind knowing that if i decide to autox or drive the engine harder or higher rpms, that i have purchased the oil that has a better reputation (in my eyes) as far as internal engine protection goes.

Maybe if Mobile1 had polishing molicules then i would switch back, but I've come to trust RP over the years. I guess you have to try it before you dismiss it as marketing hype.