My Boxster has a sticker that says, "Mobil 1 Only" but my favorite engine builder says Mobil 1 isn't the best anymore. He recommends Brad Penn conventional (non synthetic) oil but has no reccomendation for synthetic. What does the GRM community recommend for a good synthetic oil?
This is one of those you ask 5 people you will get 7 answers. I have and always will use mobil one, as did my father. Check out bobistheoilguy forums
Since opening my shop I've found oil preferences are closer to religion and politics. Some people will defend their choices to the bitter end. Truth is there are a lot of good oils out there today.
For my vintage stuff I used Brad Penn. For late model daily drivers I use Kendall GT1 Full Synthetic. For racers looking for a full synthetic I recommend Red Line.
I've stuck with Mobil1 simply because it's available at Costco. That's the extent of my research
As noted above ^^ closer to religion than fact. Unless you're building a 2000-hp dragster where every tiny bit of friction means power, most of the major synthetics will do the job.
I've used Shell Rotella T6 on all my cars, basically forever. BITOG doesn't like non-German Mobil1 in Subarus, apparently it is "thinner" than its viscosity indicates. I used it in the Maxima for a while and had a lot more leaks for some reason, but YMMV....
We use T6 in the rallycross car, in the enduro car, in my tuned DD WRX, in the tow rig, etc. It's highly recommended on BITOG for many applications, and even better you can buy it on sale at Wal-Mart damn near every other week in gallon jugs.
But as suggested above, if you really want a bunch of geeky "scientific" analysis of different oils, just go to the BITOG forums and you'll get plenty of that :)
I use Rotella T6 diesel oil in my older flat-tappet cars, like my Alfa 164, that benefit from high ZDDP (zinc) content. For my newer cars like my Mustang I use Pennzoil Platinum.
castrol syntec is my personal preference for my wifes DD, ran valvoline vr1 20-50 in my capri, run rotella in my wagon for the zinc content. Everyone has a personal preference, from working as a grease monkey i can tell you most people even ignore the manufactures recommended weights most of the time!
I wouldn't use Brad Penn on anything with a CAT. I goes in the barracuda but not the volvos.
I've never had an oil related issue to be honest and I've never used anything fancy just what ever synthetic was on sale. I have used the high mileage stuff on the my higher mileage old cars but since I'm simplifying the fleet right now, I won't have any of those for a bit because my oldest engine only has 40K miles and uses absolutely no oil.
Figure out the manufacturers spec, and buy an oil that meets it. Modern oils meet all sorts of different requirements for different reasons.
Brand names mean very little. Its the fine print on the back of the can that makes the difference.
You may also find, although its less likely with Porsche, that there is actually a higher spec in the European manual than there is in the North American one. Europeans appreciate quality, Americans appreciate Walmart prices...
For the Boxster, you might as well stick with Mobil 1. It works and is not particularly expensive. Especially if you buy at Walmart or Costco.
If you really want to find out if your oil is working, go and have it analyzed at Blackstone Labs.
Personally, 30 weight Redline Race oil hasn't been holding up as well as hoped on my Spec Miata. I'm trying Schaefers and Amsoil next with samples being sent for analysis.
Streetwiseguy wrote: Figure out the manufacturers spec, and buy an oil that meets it. Modern oils meet all sorts of different requirements for different reasons. Brand names mean very little. Its the fine print on the back of the can that makes the difference.
This. If you want to make a decision based on objective evidence, track down the manufacturer's requirements. If you really want to dig deep into it, you can even figure out what the technical aspects of those specs are and compare them to specific oils. There are lots of things to consider beyond the name on the bottle and the X-wX numbers. Just because the latter seem to match the spec doesn't mean they really do. One specific example: lots of modern BMWs spec 5w30; lots of owners use Mobil1 in that grade. The problem is that the standard Mobil1 5w30 doesn't come close to meeting actual BMWs specs (LL-01, itself based closely on ACEA A3/B4) - it is too light-in-grade and doesn't provide the necessary additive packages to meet BMWs longevity requirements. The result? A likely contributory factor to the sludging problem so common in modern BMWs that run anything close to the factory OCI, and probably some other stuff as well.
If you don't care about all this, just pick the one with the prettiest bottle and call it a day.
Mobil 1 has treated me well and as others have noted, it's about 1/3 the price for a 5 quart jug at Walmart vs. part stores.
Mobil 1 High Mileage in the Volvo.
Mobil 1 ESP in the Jetta to meet VW's requirements.
Rotella T6 in everything else.
I've been using Amsoil 5/30 in both the Integra and the a-x/TT CRX for yrs now …
seems to be fine .. though this yr for some reason the CRX still shows 80psi (mechanical gauge) at WOT, at idle it has started dropping farther more quickly than ever before … it's been suggested that I switch to, as high as 20/50 …especially since the car is seeing more track time than ever
I'm another member of the "Rotella T6 in everything" club and have had nothing but great results.
I run the Rotella in the disco as that was what the mechanic who did some work to the truck before I bought it recommended.
I have a friend who's a frequent poster on BITOG and has had Blackstone UOAs done on multiple vehicles and really, REALLY gets into this stuff. You know what he runs in his cars? Whatever's on sale. Seriously, you can't possibly go wrong with any of the major brands.
I've spent some time over on BITOG, not posting but quite a bit of reading. There are some interesting specs/lab results but also if you spend much time reading you'll soon see that there are lots of variables that influence results. Also, there doesn't seem to be a high correlation between mediocre lab results and higher engine failure.
In my experience (over 5 years) with my 6.0 LQ4 in my truck, I've found that when towing heavy through the mountains, my truck uses some oil. More so with synthetics. I've tried Mobil and Castrol Syntech each more than once. Same results. It uses less when I use Castrol GTX dino oil, so that's what I use.
I tore it all down yesterday to do cam and heads. It's very, very clean internally. Engine has about 230,000 km on it now. Looks like it's got lots left in it.
Yeah, I run whatever synthetic is on sale as well. The caveat there is that I have owned mostly Japanese and American cars.
To be honest, in the year or two I spent as a mechanic, I rarely saw a Japanese or American car, owned by maintenance-conscious person, that really had any oil-related problems at all. The issues related to sludging, excessive wear of oiled parts, etc. were usually because the owner did 20k mil OCIs or thought the oil light on the dash just meant "hey, add a quart or so, if you have a minute." Even the cars that had been getting Walmart $19.99 oil changes for 100k miles looked fine inside.
@ the OP I would stick with what is ever the car MFGR sais.
If it has a warranty of any kind you are keeping this kosher
If you ever decide to re sell you can advertise that it has always had mobile one as per the MFGR.
If you are going to keep it and drive it in to the ground use good quality Synthetic and go have fun with it.
ShadowSix wrote: To be honest, in the year or two I spent as a mechanic, I rarely saw a Japanese or American car, owned by maintenance-conscious person, that really had any oil-related problems at all.
Valvoline had a deal that if you used their oil and changed at regular intervals, they would warranty your engine for 300,000 miles against oil related failures. They wouldn't do this unless oil related failures were all but nonexistent.
AMSOIL of course.
In my race car - Mobil 1 0w40 runs 15-20F cooler on the gauge than some leading "red" branded racing oils purported to be made with the choicest bits of bald eagle vagina and priced accordingly. When I send M1 to blackstone after a whole race/instucting/track day season of abuse they say it's still good. Plus, I can buy 5qts of it at Wallyworld for $25. In rural West Virginia. On Sunday. At midnight. Along with beer and cheetos.
So best? I can't say. Good enough? berkeley yeah.
I usually run what's on sale cuz cheap bastard. But the HLA's in my Mazdog seem to run quietest, for longest, when I give it Pentosil. It's the stuff AMG specs, apparently. But I have a case of Amsoil I plan on putting in the rallycar next, and still have some mobil 1 left on the shelf. Delo 400 for the diesel rigs.
I've used garden-variety convetionals, Castrol Syntec, Castrol Syntec Edge with Titanium, Mobil 1, and Royal Purple in my '09 Impreza.
The two that stand out as performing better were the Castrol "Titanium" and Royal Purple. The "Titanium" oil gave my engine a really subdued, smooth sound. The Subaru EJ25 is not known as a quiet motor, but things were much improved with that oil.
It's a bit overpriced, and doesn't have a very good reputation, but Royal Purple seems to give a definite improvement in perceived acceleration, and also seemed to improve mileage in my (admittedly limited) testing. I get around 35mpg (as indicated by the Subaru electronics) on the highway at 65-70mph when running Royal Purple, versus maybe 32mpg or so with other oils (and versus 26mpg claimed by the EPA).
And I would disagree with anyone who says that this has to be a subjective discussion. Check out Amsoil's own study at www.amsoil.com/lit/g3115.pdf. For the most part, I think their findings validate my own seat-of-the-pants, semi-scientific findings re. what's good versus what's mediocre.
How about for a euro gas motor with over 320k miles? 
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