I am curious to know if all synthetic oils are basically the same. Are there only marginal differences between leading synthetic brands? I probably know the answer to this, but is generic full synthetic oil pretty much the same as a brand name synthetic such as (10W30 Quaker State, Pennzoil, Castrol, Mobile1, etc.)? If not, what synthetic oil is the best for price? I personally think oil is important enough to not go cheap on, but what is the most cost effective synthetic? Thanks all my fellow happy Subaru lovers!

Did you try searching this one? I hate to open this can of worms again (synthetic oil debates). Theres also TONS of google searches that would probably compare some.

 

IMO Penn, quaker, etc aren't meant for a Subaru. Mobil1 and Valvoline are the best IMO. Amsoil and other not so major oil company oils seem to really have some quality and backing around here too.

Why aren't Pennzoil and Quaker state oils meant for a subaru? I've lately been using Pennzoil Platinum 10W30 and it's been good.

Why aren't Pennzoil and Quaker state oils meant for a subaru? I've lately been using Pennzoil Platinum 10W30 and it's been good.

 

 

I use Mobil1 or Castrol synt. whichever is cheaper

this gets asked all the time, use the search button and read yourself asleep....

 

I've lately been using Pennzoil Platinum 10W30 and it's been good.

he's not saying using those oils will immediately incinerate every car they are used in. there's lots of debate and little quantitative useful information to the average car owner. yes there are differences, but the bottom line seems to be that the net results of those differences don't amount to anything substantial/functional in the real world (my oppinion). in other words...you're much more likely to have water pump, alternator, suspension, driveshaft, transmission or some other problem before the fact that you used "X" oil ruins your engine or keeps you from making it to 200,000 or 300,000 miles. change your blah blah blah synthetic oil on time and subaru's make 200,000 miles no problem, period.

The basestocks in synthetic oils of course are either group IV (PAO) and/or group V (ester), and some companies will say group III is synthetic although is actually made from petroleum. There are different quality levels of basestocks. The additive pack is critical also as you need quality AW anti-wear and other additives (antioxidants, etc.) and there are many types available to the oil blender, some are cheap and some cost more. If you look at the specs on various oils, you will see many differences between the pour point, flash point, TBN, viscosity at various temperatures, HT/HS, etc., all of which must be weighed determining on the application. Often, the blenders buy the additive packs from places like Lubrizol, who then suggests a basestock to use with it to meet the target specifications such as API-Swhatever.

Here in Fairbanks Alaska it can get very cold (-50 F or colder) and I don't have a garage so I use the Mobile 1. Car starts pretty good after it has been plugged in for a while.

I use Mobil1 or Castrol synt. whichever is cheaper

 

Mobil 1 is a full synthetic, Castrol Syntec is a synthetic blend. They are two entirely different oils and not comparable.

 

Personally, I only use full synthetics.

 

Jack

Mobil 1 is a full synthetic, Castrol Syntec is a synthetic blend. They are two entirely different oils and not comparable

 

 

Sorry jack but you're wrong on these one. Castrol syntec is a full synthetic

Wasn't this the issue that whole law suit was about? I think Castrol said group III basestocks are synthetic, someone suing them said no they're not synthetic because they're a highly refined petroleum product, but I don't remember the outcome.

I think that if you change the oil every 3K miles, then Syntetic does not pay for itself. However, If you have multiple cars and tend to forget to change the oil on a regular basis, then Syntetic can save you.