Castrol GTX is not synthetic.
Castrol Syntec is the synthetic that Castrol sells.
I use Castrol Syntec and have used it for years.
Everything you ever wanted to know about oil is here.
http://www.bobistheoilguy.com/cms/

 

if you are going to use Mobil1, one of their better oils is the M1 High Mileage. It is a better stock that is API SL, with higher levels of Zn & P, plus some seal conditioners. I use the M1 HM 5w30 in my 50,000 mile '03 Aviator and my 18,000 mile '03 Cobra.

This will help too:

http://www.mobil.com/usa-english/motoroil/files/mobil_1_product_guide.pdf

As for Castrol, their best is the German 0w30 - available at AutoZone. Used to use it it my previous S60R all year long and ran 7,500 miles between changes. The Blackstone used oil analysis showed it could have easily gone 10,000 - 15,000 miles, and I sure didn't granny drive that car!

 

I just changed with Penzoil Platinum based on the advice of AutoRx which I'm doing a cleaning phase of right now. Otherwise I use Castrol High Mileage regularly. (5w30).

 

Another oil thread?

Mobil 1 FTW!

 

Thanks all you guys!

 

Mobil1 0W40 Euro, Pennzoil Ultra 5W40 Euro and Castrol Edge 5W30 are all good oils...I'm using Pennzoil now, Ultra is better than Platinum.

 

I've just been using Mobil1 5W30 Synthetic in mine. Haven't had a problem in it since. Finding synthetic oils is much harder than I would've thought.

 

Pennzoil Ultra 5w40 Euro ......

 

I'm using it

 

castrol

 

I don't get the Euro thing entirely. I feel like a n00b.

 

With 130k miles, I just switched from regular Mobil 1 to their High Mileage 5w30, about 4000 miles ago. Engine is definitely cleaner with the addins in the High Mileage version. I definitely recommend this oil and will be using it from now on.

 

Is High Mileage 5w30 fully synthetic?
Does any one have experience to use AMSOIL or Royal Purple?

 

Yes it is. No experience with Amsoil or RP though.

 

I was going to chime in about Shell Rotella 5w-30 T6 Full synthetic, but I have used AMSoil in the past in all my Audis. Night and day difference when comparing to Mobil and Castrol( Both Synthetics) , especially during cold winter start ups. I can post a thesis I wrote in college when I compared AMSoil vs Royal Purple on a chassis dyno.

Currently I have a base P2 2.4i, automatic as my DD, great car love the HWY MPGs, anyways I just changed the oil a few weeks ago and used AMSoil 5w-30 synthetic. I plan to run it for 5k and see how it does, and in the winter run 0w-30. So far its very smooth, and quieter then before, the previous owner took it to the dealer for all services and they used Castrol Syntec, which I dont mind. I used it in my 99' A6 avant with 115k on the clock and never had problems. The reason I decided to use AMSoil in the Volvo is purely because it runs much smoother then Castrol, and Volvos vibrate when cold. Coming from Audi's I always notice it, mostly in the morning when its cold. But I also remember my fathers 1990 740 which he purchased new and it too vibrated, and so did his 850, P1 V70 etc etc, just something you get used to. I havent driven a R model yet so I dont want to say ALL of them do. I know lots of it has to do with all the various engine mounts, (which fyi have been replaced within 15k by the previous owner) No after market mounts either all O.E.

 

thanks for all you guys' reply.
The reason for I to start this topic is that I have read some articles show some figures of tests. Based on those figures that Amsoil is always at the top. The price of Amsoil in CT is pretty much at the same level as M1 and RP. My confusion is taht some threads metioned that Amsoil is not so good as it claims and it just put lots of money on marketing. I have no experince on oil change before. And I got this T5 at 100900 KM. So far I love the car very much. Because it is a high pressure turbo, should I put more concern on oil change?

 

With turbo charged engines, the oil quality is important. It is also important in naturally aspirated, the key is to maintain a schedule or monitor your use throughout. I have used M1, and has positive results, although it does seem to burn off at a higher rate when compared to Amsoil. I always went by this rule from my automotive courses, 3 months or 3k miles, always changed between winter and spring in the NE. With synthetics i typically go 4-5's 4-5k miles depending on your driving habits. Hope this helps

 

I hear Pennzoil Ultra is some really good stuff. I'm not completely sure, but a family friend of mine bought a 5 Quart Jug of Ultra from Walmart for about $20 on sale. Ultra is a tier up from the Platinum. I heard Mobil 1 has recently downgraded their level of oil, but it's just a rumor.

 

Peter, I am totally agree with you!
You are right that some users also metion that M1 burn off a little bit faster. What the cause for that?
Regarding Pennzoil, some threads from other cars' users metion that it's a little bit easier to get sluddged. I am not sure whether it is ture.