Can someone explain why this oil is so highly respected? What are its strengths? The more detail you can give the better.
I went ahead and put it in my truck and my car (the new gold stuff.) I like to buy ANYTHING made in Germany. But can someone please explain what it is about this stuff that is so good. Does it have any weaknesses?
What is all the hype about German Castrol?
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GC 0W-30 is a heavy duty, long-life oil that meets many of the more difficult Euro specs. I don't know if I would call it a weakness, but because of its ability to resist shear at high temps and it's viscous nature, it will not be your best alternative for fuel economy, if that is what you are after. There are better choices for that purpose. But for engine protection it is rather stout, especially if your engine calls for one of the Euro specs.
As a contrast, Mobil 1 0W-30 will probably return slightly better fuel economy figures, but will not protect or hold up as well in high heat, turbo, DI, type engines. It's made for fuel economy in apps calling for 5/10W-30 API SM.
It's a good oil. But within a span of just a few years many oils caught up and passed GC. The best deal is the price - you can score GC for Syntec SALE prices!
Originally Posted By: Pablo
It's a good oil. But within a span of just a few years many oils caught up and passed GC. The best deal is the price - you can score GC for Syntec SALE prices!
)
I don't want this thread to get rhetorical and yeah-yeah.
There are more robust oils and there are oils that fit the application with more precision than trying to shoehorn GC into every engine/application.
Originally Posted By: buster
Quote:
What oils are better than GC? (Please say Mobil1 0w40 )
) GC is a fine oil. I prefer M1 products to Castrol personally.
http://www.mobil1.com.au/why/outstanding.aspx
I switched my BMW from M1 0W40 to GC and it was a positive experience. Less shearing, far less under-hood noise, higher TBN at the end of my intervals.
I switched my dad's BMW from the dealer synthetic oil - an ACEA A3/LL-01 5w30 - (he only runs half of the OI OCI) and it was a miracle transformation. At only 80k km it used to sound like a diesel about to die - clattering lifters, bottom end knock at low rpm etc... GC shut almost everything up within 20 seconds. Everything else totally disappeared after a round of ARX. Now at 150k km it purrs. It now gets GC every 10k km or so.
M1 also got good UOA results (except for shearing like crazy) but I had three vehicles get noisy on M1 products. I believe it was when the switch to the API SL formulation took place - I forget which of SuperSyn, TriSyn etc... I wasn't as attentive, and never thought to blame the oil (I had been brainwashed into "M1 is the best" at the time) but I noticed a BMW (0w40), Porsche (15W50 red cap) and Acura (5W30) all get noisy with lower frequency cam noise and general under-hood "hash". The second I put anything other than M1 in suddenly all I could hear was alternator and PS pump. I won't be going back to M1 for anything unless there's a darn good reason because of this. The UOAs were fine, but I don't want to put up with the racket when lots of other oils like GC also get good UOAs.
Amsoil SSO may be a great oil, but the current posted specs show it being nothing like GC (other than saying 0W30 on the bottle). It's in the 10cSt range, and HTHS down near 3. It's an energy conserving oil, not a high HTHS euro oil. I think Amsoil's only appropriate offering to compare is AFL 5W40.
With GC my UOAs are great, my engine sounds great, looks great, and still gets good-enough-for-me fuel economy (36-40mpg on the country highways in a 5-series BMW with wide summer tires). I'm in Canada so I appreciate the 0W part of the rating. If I was in the mid/southern US I'd probably just run a 15W40 HDEO year round.
I also use GC in my snowthrower due to its shear- and fuel-resistance while retaining excellent cold properties.
GC isn't for everything, particularly not fuel-efficient four cyls like Hondas and Toyotas. For anything requiring ACEA A3 and higher HTHS give it a look - especially if it gets cold where you are. A lot of four cyl owners have said they love the quiet and smooth quality but it robs too much power and fuel economy to be worth running.
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JHZR2
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Originally Posted By: buster
Quote:
What oils are better than GC? (Please say Mobil1 0w40 )
) 
Originally Posted By: Craig in Canada
36-40mpg on the country highways in a 5-series BMW with wide summer tires
Originally Posted By: Quattro Pete
Originally Posted By: Craig in Canada
36-40mpg on the country highways in a 5-series BMW with wide summer tires
Originally Posted By: Quattro Pete
Originally Posted By: Craig in Canada
36-40mpg on the country highways in a 5-series BMW with wide summer tires
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Originally Posted By: KLowD9x
Originally Posted By: Quattro Pete
Originally Posted By: Craig in Canada
36-40mpg on the country highways in a 5-series BMW with wide summer tires
Originally Posted By: Craig in Canada
Seriously though, do you drive stick or auto? I have stick, and the best economy seem to occur on cooler summer evenings when you don't need the AC or the windows wide open. A lot of M62/TU drivers say they get best economy over 80mph. I've found my M52 is best around 50-60mph and downhill from there. If you're trying to compare Interstate conditions to rural, don't bother. I can get near the upper 30s on interstate-class highways.
I run Esso AKI 91 fuel with FP3000 (Esso gives the best performance and fuel economy of the major brands around here in this car), GC, Amsoil MTF or Redline MTL in trans, Redline in the diff, factory sport suspension ride height and alignment, factory style 5s 235/45/17 shod in PS2s running slightly higher pressures than sticker (like 33/35 F/R).
It's made by the Keebler elves. 
Originally Posted By: Quattro Pete
I've got a manual. The mpg I listed is with cruise control set at around 70 mph on an interstate hwy, running Shell 93, GC, RP Synchromax in the tranny, and Redline in the diff. Same factory sport suspension and OEM 17x8 rims with Bridgestone RE960 235/45/17 tires.
Considering EPA rates your car at 26 mpg hwy, you're beating it by quite a bit. Just to make sure, we're talking about US gallons, not imperials ones, right? :)
Ah, English units. That explains it. All is forgiven.
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