What's the best synthetic oil?

thanks … good info .. I'd heard that Rotella had the higher zinc content, but hadn't heard why that was "bad"

We may have a few industry experts chiming in this thread soon. They have been invited, so please know in advance these aren't canoes--- but folks that know much more about this stuff than most of us. The more information we can get--- the better informed we'll all be.

There is a ton of science that goes into modern oil formulations. What is perfect for one car, may not be appropriate for another.

Great thread by the way!

Mobil 1 in almost everything

Mongo uses low ash 50 weight Rotella

The new Mustang engine will probably be Amsoil.

Amsoil in all the gearboxes and differentials

Fantastic thread, staying tuned in for the experts to chime in

Joe Gearin wrote: This year we had Harry King (Millers Oils).......

That'd be me. And for the sake of clarity (and to let their lawyers sleep well tonight), I'm with the North AMerican distributor of Millers, I'm not the parent company. So views I express may not be shared by Millers, Ltd. of the UK.

This is a very complex question. I could probably talk for an hour about it. And maybe only put half the people to sleep.

At any rate, this is a very good article that is a good primer for oils, particularly in motorsports types of applications. It predates the launch of the Millers Nanodrive line of products that use nanotechnology, but is still a very good article that outlines many of the factors that go into a good oil. From Race Engine Technology: http://performanceracingoils.com/PDF/Race_engine_tech_Reassuringly_Expensive.pdf

A few things that I've read here. I'll try to avoid talking too much about other brands of oil, but I will address the original question. I don't work for Porsche, never have. However, I did engine development for Ford for a number of years, including the timeframe when Ford started putting the BP Starburst on its gas caps. I can tell you that engineering had NOTHING to do with that decision. And I can also tell you that when we've met with some teams during testing, one of them finally was frank with us and said WTTE: "Look, this sounds like really good stuff, and I appreciate what you are trying to do, but it is like this. I go through a lot of oil, and I have a budget. Mobil 1 drops off a pallet of oil free of charge at my shop once a month." This was a Grand Am team in the Summer of 2012, and apparently they do it for all of the higher level (at that point Rolex) teams.

So, Mobil 1 gives away a lot of oil. A LOT of oil. To outfits that don't have a lot of visibility. Based on the two experiences above, I can say that it is extremely likely that that sticker under the hood that says Mobil 1 is not there because the engineers had anything to do with. Actually, the converse is likely the case based on my experience with German engineers. I would say that the German engineers probably wanted some German oil in there.

I'm sure a few of you just nodded off when I wrote the phrase "German engineers." Martini's come dry, extra dry, and German Engineer dry. Talk about no sense of humor (and yeah, I've got a lot of German in me, and I'm an engineer, so I'm pretty qualified to know that).

Where was I? Oh yeah, what to put in the Porsche. As Joe mentioned, most of the street oils are fine. For STREET use. I wouldn't consider putting a street oil in a car that gets tracked. Can you do it? Yes. But the oil will break down very quickly, meaning you have to change it often. Like daily. For comparison, most good race oils use lots of Group IV and V base stocks. All street oils are Group III. The difference in flash point between the primary base stocks in race and street oils is about 80 degrees C (~150 degrees F). No, you don't reach flash point on the track. But it is a pretty good surrogate for how well the oil can handle the heat......and that is just the base stock. Viscosity improvers are another factor. And the additive pack is yet another.

Anyway, the Boxster's factory change interval is pretty long. Way too long for a conventional oil. You need an oil with a healthy additive pack. Porsche has a spec, A40, which is pretty fair to look for. Note there are "meets spec" and "approved." They are kind of the same, and kind of not. Some will give some generic "exceeds" spec, which you have to be careful of. Note that approval is very tight, and requires testing by the OEM. But that doesn't always mean that an oil that isn't on the approved list is inferior. For example, we carry several street oils that use the nanotechnology (NT) that was developed for motorsports. Their non-NT counterparts carry approval from BMW (LL04), Mercedes (229.51), Porsche (A40), et al, but the same oils with the NT additive will not be given approval, but still meets specs.

As for "exceeding" specs. There is no hard and fast rule, and marketing plays a very, very big role. Let's say that an OEM calls out an allowable range for viscosity index (VI). But an oil manufacturer has a higher VI, so they claim it "exceeds" it. Well......VI improvers are good and bad. Good because they improve VI, but bad because they shear down. An oil with minimal VI improvers will be a much more robust oil than one without them. So while the oil may "exceed" the VI when fresh, it may not meet them after 500 miles, and if you have a 10,000 mile oil change interval, you may be driving with crappy oil in your car.

Since ZDDP was brought up, I'll talk about that a little. In 2004 when the API bumped the oil spec to SM, the max allowable phosphorus content dropped to 600 for most oils (stayed higher for the thicker grades....unless they were "energy conserving"). And Rotella was mentioned - Rotella, to my understanding, is now a low ZDDP oil, as well. ZDDP is a good additive, it puts a thin layer (~150nm) of zinc on the substrate, and it is then removed under stress (think bucket and lobe).

"Problems" with ZDDP are 2-fold. First, it is a very sticky, honey-like substance. So if you have more than you need, you are just putting unnecessary drag on your engine. Second, cat poisoning. Unnecessary drag. Well, why would you want to do that? I know why companies do put up to twice as much ZDDP in there as necessary - marketing! Hey, it sells. It was removed, the market in general freaked, so being typical Americans, we want more. More is better. Except when it isn't. And just like a 128 ounce coke with your value meal with the lowfat salad dressing, it really is only doing to drag you down.

Cat poisoning. Not Tinkerbell, the other kinds of cats. So this it, IMHO, overblown pretty much. The levels changed in 2004. Cats haven't really changed all that much in that timeframe. But, I think there are a few factors. OEM's must warranty emissions components for 8 years, or 80,000 miles. And cats often cost more than engines. So it is in the interest of the OEM's to not have their cats at risk. Also, they've gone away from buckets and more towards roller followers to save fuel. And yeah, that sticky ZDDP won't help fuel. But there are now things like DLC which help alleviate the need for ZDDP where buckets are used. But, what causes cat poisoning is when there (excessive?) is consumption, particularly in higher mileage cars with thinner oils, OVER TIME, the phosphorus can weaken the ability of the cats to work. Of course, anyone with a Mazda right now is probably going (what's excessive?). For you folks, I'd just move where they don't have inspections, and get rid of the cats. For everyone else, I have some good news. Cat poisoning is reversible! Turns out, all you really need to do is get the cats really hot. Say.....at a track event! So if anyone is wondering if they can run race oil in their tracked drivers, yes, you can.

Okay, so I'm sure there are more comments, now, since I started working on this about 6 hours ago. SO I'll check back. Besides, I just got some mass e-mail from BS Levy. And if you know who he is, you probably know why I'm going to go read it. And if you don't know who who he is, shame on you, go find out. Then buy his books. All fo them. Because you'll read the first one, and then you'll realize you should have just bought them all up front.

By the way, on edit. I don't really like BITOG. A lot of misinformation originates there, even from folks who have written editorials. One has some connection, not sure what, and is quite defensive to the point of insulting and belittling others rather than discussing the data. Also, UOA's are a great tool.......if you know hwo to read them, which means you know what the VOA is. Esters (Gr V) will show up as oxidized oil, though it isn't. The NT additive shows up as nickel, but it isn't.

I use Amsoil in pretty much everything and have since about 1975. That includes 2 passenger cars, a race car, diesel van, diesel tractor, lawn mower, generator, power washer and a number of 2 cycle landscaping tools. Amsoil has a wide range of motor oils today to meet almost any specific need and in my opinion are superior with all of them. I have flirted with others like Mobil 1, but always come back to Amsoil. Yes, I am a dealer but about the only others I "sell" to besides myself is my son.

The only place I have gone with a different oil other than Amsoil, or in some cases like auto transmissions, OEM, has been in my 2001 Audi A4 5 speed manual transmission. When I used the recommended Amsoil product, 75W90 GL-4, I struggled with very stubborn cold temp syncro matching issues. I switched to Redline MTL which is a slightly lower viscosity and slightly higher friction product for which there is no Amsoil equivalent and the transmission was happy with that.