I was just wondering what people think about CastrolSyntec?

The only good one IMO is the Castrol Syntec 0W-30 a.k.a. German Castrol. It is made in germany and is a good oil. The other ones suck

2003 Audi A4 1.8TQ
Amsoil 0W-30 Synthetic
Amsoil Full Flow synthetic/cellulose filter.

Apparentally, the 5W40 "Belgian Castrol" is pretty decent too, though I have no personal experence with it.

In my oppinion, it isn't so much that the American Castrol (10W30, 5W50) etc perform badly, it is more that they are radically over priced Group III oils. It is sort of like a Fram oil filter: your engine probably won't fall apart but you are definitely paying more than you should for the product you receive.

robert_korn_226, I understand your high on castrol syntec because it"s a factory fill on some vehicles, but let's me make an analogy. You can use factory ammunition for a weapon, but to compete, you have to reload your own. You can always improve on factory made performance. Reloding your own, gives you the flexibility to more closely match the ammunition to your specific weapon. Big business uses whatever works at a cost they can afford, don't ever think it's the best! Just because Castrol is a factory fill for BMW doesn't make it the best, it works and at a price they like, or they would use Mobil, shell or Valvolin whatever!

2003 BMW 325i
Dinan CAI, Throttle body
Dinan Exhaust
Dinan stage 3
Dinan Strut Braces

lpquick, I understand what you are saying about the fact that manufacturers use what ever they can get cheapest but something that catches my eye is that most manufacturers will not even tell you what they put in the cars they make so what I am trying to say is there must be something good about the oil they choose whether it be Castrol, Mobil, Shell and so on if they are brave enough to say what they put in the car factory fill. By the way I am not "high" on Castrol because it is factory fill in cars I am just a beleiver in how well it performs because my family has been using it for years and we have owened cars that has had well over 400,000 miles on them and I like to keep in mind that one reasone that they can get so many miles on them is because of the oil we use. As with me pointing out the manufacturers that use it I just think they must think they are using a good oil to say what they use in their cars and trucks or they just have big balls and really don't care. You choose.

I have been using Castrol Syntec for some time, but am concerned with all I have been reading about how they are not true synthetics.....my question is, even if Syntc does not hold up to the definition of synthetic, isn't still a good oil to use??? OR, would I be much better off going with Amsoil, etc???

Well, it is an OK oil. Cold weather performance and extended drains are probably its big weak points. Like we said before, only the US made versions are the fake syn oils, the 0W30 German made oil, known as GLX in Europe is great stuff.

The US versions are radically, obscenely overpriced, and not particularly good choices for extended drain intervals...which makes them an even poorer deal. Sort of the Fram of oils, Castrol did at one time sell a quality oil in North America, but now rides on advertising and past reputation.

There is no reason to be conserned about switching oil types with modern oil, so you could certainly switch to a real syn oil like Mobil, GC, Amsoil, etc. Conversely, you could switch to a good dino (Pennszoil or Chevron for my preference), change at 3,000 miles and see the same performance.

Having said that, modern oils don't kill cars. If you feel better running syntec, and money isn't a concern, go ahead and run it.

Thanks for the reply. I started using Castrol Syntec to save money 2* extending drain cycle. So, I need to change my ways a bit. If I was to go the Amsoil way, what is the drain schedule look like for a V6 4Runner 1999? Also, do you recommend their bypass filter system?

I'm sort of ambivalent towards Amsoil personally, so I'm not the best person to tell you how to use it. It isn't so much that their products are inferior, more that the marketing end is annoying. The actual drain schedule will depend heavily on the driving conditions/ and how much you drive in any case.

I would avoid Amsoil's, or anyone else's bypass filter on most personal cars. I know very, very few people that drive enough miles, and keep a car long enough for it to pay off.

The big consideration with extended drains, is to do at least some oil analysis work. Now, if you're just stepping up from 3,000 mile changes, you can feel very safe going to the highest reccomended change interval, on a healthy engine...typically 7,500 miles, espically with syn oil.

A couple of links for you:

http://neptune.spacebears.com/cars/stories/oil-life.html

http://neptune.spacebears.com/cars/stories/mobil1.html


I basically agree with the above links, running Mobil 1 for 8-10k miles without a filter change, or 15k miles with 2-3 filter changes is a pretty good plan. I can't remember how hard it is to pull the filter on a 4-runner, but if its a real pain, I would go for the 8-10k change and only change the filter with the oil.

A comfortable plan for lots of people is an oil change ever 6 months with Mobil 1, or once a year on a car that only sees ~10k/ year.

Arbus, Thank you again for the information. Changing an oil filter on a 4Runner is a PITA, so I think I will go the 7.5K and see what happens. On thing I noticed with the Syntec @ 5K is a MPG drop and the engine ran rough. I know it was the oil because as soon as I changed it MPG came back and the engine idled smooth again...kinda scarey. That is what prompted finding this web site....what great info!!!! Can't wait to see what Mobil 1 will do for me!

Well I have read and had to write. I have a 94 Nissan pickup with 140000mi. used CASTROL SYNTEC from day 1.Never a problem with my 5000 OCI. I Am now using AMSOIL in all 4 of my cars.I have run OCA on many types of oil and never have to worry with the AMSOIL. I buy a discount card for $10 and pick up their stuff in gallons.The Tranny fluid too. It is the same price or cheaper as Mobil 1.I can go 7500 or 5000 whichever I choose cause I know the oil can handle it.

I do not think there is anything inherently wrong with the syntec's . Maybe a bit overpriced compared to some other slightly superior performing longer drain oils .

I like the Imported Castrol 5w-30 that the BMW dealers have at less than 5 dollars a liter . It is all synthetic chemistry and will go the distance .