Castrol Syntec Question

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Is Castrol Syntec commenly called "GC" on this forum? I thought "GC" was originally German Castrol that was green in color. I assumed that German Castrol was brought in from Germany/Europe, but I don't really know. I ran some dealer Castrol in my 2004 Tundra and then switched to Mobil 1 before I sold it. I'm currently running Pennzoil Platinum in my 2004 Sequoia and am considering options to improve fuel mileage as my wife has a longer commute as of last week and any savings would be nice. I'm currently running 5w-30, but might consider going to 0w-30 if I thought it might help. With 75,000+ miles on the clock I'm a little concerned by Mobil 1 finding some leak paths since I have had it leak out of engines that nothing else did. Mostly looking for some GC clarification.
 
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You are close.. apparently some of the Castrol sold at certain stores is still made in Germany - check the bottles. the german stuff is better and has a stronger add pkg. oh, and I am running off of memory from something I read - so I could be wrong...
 

KW

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You might pick up a little better fuel mileage going to a synthetic oil. But really proper tire inflation and slowing down to about 60-65ish will show the most improvement.
 
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Of those oils I doubt you'ld see a difference. In winter in short commutes, maybe. I save fuel on long highway commutes by running thicker oil. Keeps the fuel out of the oil pan and keeps the effective cyl pressure up. I dont like thick syn though.
 
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I'm skeptical that you will get much benefit in the way of increased gas mileage by changing the viscosity of you oil by 1 or 2 cSt. Ford only reported a 0.6% (less than 1%) increase in gas mileage with the move from 5W-30 to 5W-20, which represents a drop in cSt viscosity of ~ 2.0 cSt (10.6 to 8.6 cSt). You could do much better by pumping up the air pressure in your tires 5-6 lbs. One can get a good increase (several %), by going from low 30's to high 30's. Although, I've heard it said on hyper-mileing sites, that there is diminishing returns after you hit about 40 - 45 lbs pressure.
 
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0W-30 Castrol is the only stuff made in Germany and is the ONLY Syntec known as GC. Nothing else. Not 5W-20, not 5W-30, not 10W-30 etc.
 
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your mileage will not be any different on highway trips. you may get slightly better mileage if you do frequent short trips, because the 0 weight is very slightly thinner when cold, but the difference would be very negligible. The only way to get better mileage in a Sequoia would be to use your cruise control, and keep it at a steady speed of 55-65. Pennzoil Platinum is an excellent oil, with extremely good low temperature flow character.
 

blackdiamond

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I'll look at tire pressures, I'm not that concerned about wear since I'd love an excuse to replace the nearly new tires that came with it. The OEM Dunlops simply stink on wet pavement and I want Goodyear Triple Treads that were excellent on my Tundra. I might keep my eye open for some 0w-30 GC as the butt-o-meter didn't like the feel of the PP in the Sequoia, it felt fine good in the Mazdaspeed and my 89 4Runner so it's nothing against the oil. I'm just looking for an excuse to change I guess. Oh, I have never driven a car that got better mpg on cruise than I did using my steady right foot, but it's my wife's rig so I don't contribute much in this case. I always feel safer without using cruise because it keeps me focused on driving and more alert overall.
 
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 Originally Posted By: blackdiamond
I'll look at tire pressures, I'm not that concerned about wear since I'd love an excuse to replace the nearly new tires that came with it. The OEM Dunlops simply stink on wet pavement and I want Goodyear Triple Treads that were excellent on my Tundra. I might keep my eye open for some 0w-30 GC as the butt-o-meter didn't like the feel of the PP in the Sequoia, it felt fine good in the Mazdaspeed and my 89 4Runner so it's nothing against the oil. I'm just looking for an excuse to change I guess. Oh, I have never driven a car that got better mpg on cruise than I did using my steady right foot, but it's my wife's rig so I don't contribute much in this case. I always feel safer without using cruise because it keeps me focused on driving and more alert overall.
Buy the tires you want and put the Dunlops on eBay while they still have some tread on them. I've found the same thing regarding cruise economy. Cruise control will rev the engine to maintain 70 going up a hill while the foot will allow the vehicle to slow down a little and not change throttle position, so the foot gets better economy. However, cruise control will keep you from getting a speeding ticket as you fly down a hill after you've revved the engine enough to climb the hill.
 

blackdiamond

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 Originally Posted By: hpichris
0W-30 Castrol is the only stuff made in Germany and is the ONLY Syntec known as GC. Nothing else. Not 5W-20, not 5W-30, not 10W-30 etc.
So is there something special with the current 0w-30 compared to the others or is it because it's the same weight as the original green stuff?
 
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The 0w30 is their "european formula". It is ACEA A3/B3 rated for long drains, and has a high HTHS for a 30wt oil. GC is probably not the oil to use if you're after better fuel economy as it's a very thick 30wt oil and not rated "energy conserving". GC is "made in Germany" and is believed to use only PAO basestocks. Other grades of syntec are primarily made of Grp 3 basestocks in the USA.
 
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Quoted from the euro section * What is GC? GC stands for German Castrol. It's officially named Castrol Syntec 0w-30. I'm not sure who coined this term. * Why is it called GC? It is the ONLY Castrol Syntec made in Germany. * What makes this stuff so good? With any oil, it may not work well with your car. However, the majority of us love it. o Produces great UOA results. o Engines run quieter and smoother. (OK, that may be an opinion.) o Comparable price with other synthetics. ~$5 qt o GC is a TRUE synthetic. Made from PAO/Esters, not Group III. Click here for more reading. + The other Castrol Syntecs are not true synthetics. Other examples of true synthetic oils are Mobil1, Amsoil, Redline, and Royal Purple to name a few! o GC is good enough to have its own forum! That's gotta mean something. * What's bad about this stuff? Not much. o You might have a hard time finding it depending on where you live. o Your car might not like it. You'll never know until you try. Keep trying oils until you find one you're happy with. o Addicting. You'll see what I mean... * Is it "thin"? Come on, 0w-30 has to be watery. NO! Please don't completely buy into that myth. o At cold temps, the 0w weight correlates to cold cranking viscosity. That means GC will still flow at cold temps. (Which is a good thing!) o At operating temps, the 30 weight is actually close to a 40 weight. GC is one of the thickest 30 weight oils around. I don't want to go into too much detail about this here. It can be very confusing. My point is, GC is not "thin" in most temperatures that we use our cars in. Click here for more details about the "Thin Oil Myth". The example uses Mobil1 5w-30 and 10w-30, but GC still applies. Click here for some viscosity comparisons. Click here for a chart about cold cranking viscosity. * Can I use this oil even if my car manufacturer recommends a different weight? Great question. Your best bet would be to search or start a new topic if it hasn't been discussed. It should be fine if your car needs 0w-30 (Duh), 5w-30, or 10w-30. Personally, I wouldn't use GC if my car called for non-30 weight. * Where can I buy this stuff? In the US, AutoZone is the only major store that carries GC. Most AutoZones carry it, but not all. In Canada, you can try your luck at AutoZone and Wally World. More information you should know: * There are 3 types of GC. o U.S. - So it's not really GC, but it's U.S. made Castrol Syntec 0w-30. o Green - Yes, the oil is Green. o Gold - The most recent stuff. * What's the difference? o There's not much research done on the U.S. stuff, so just don't buy it. o Green vs Gold + No one is 100% sure which is better. + Green has proven itself to be great. + So far, Gold has been great too! + Gold is probably just as good as Green. (Maybe better?) + Click here for more reading. o Bottom Line + The U.S. stuff probably isn't as good as the German stuff. + Buy Green if you can find it. Otherwise go for the Gold! * How can I tell the difference? First, I'll teach you how to read the date codes. o Look at the bottom of the bottle, it'll say something like M05216xxxx + The 05 represents the year it was made. (2005 in this case) + The 216 represents the day it was made. (001 - 365) o U.S. + No need to look at the date code, it'll say "Made in the U.S.A." on the back. + It was last made in 2002, but many AutoZones still have some lying around. o Green GC + It'll say "Made in Germany" on the back. + Anything until and including M05010xxxx is Green. + This stuff came out in 2002. o Gold GC + It'll say "Made in Germany" on the back. + Anything after M05010xxxx is Gold. + This is the current GC. Click here for some photos of US and Green GC. The Gold GC bottles look similar or identical to the Green GC bottles. Miscellaneous Questions: * Are you a chemical engineer or tribologist? Nope, just an enthusiast. I am an Electrical Engineer and I got A's in all my physics/chem classes. [Razz] (I still don't know jack about those subjects.) * Why do people hunt for Green GC so frivolously? I don't know. There's something novel about losing gas/time/money/relationships for the Green. * What's the deal with the elves? Shhh, don't get involved. They'll pull you back in if you try to get out.
 

blackdiamond

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Got me a case of 0w-30 Syntec European Formula today. It says Wyane, NJ on the back so it's the US version of GC, yes? The SJ, rather than SM, spec sold me on trying the product. My Sequoia calls for SJ, not even Maxlife is SJ and not SM.
 
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My GC also says Wayne, NJ on the bottom left of the back. However, it also says Made in Germany underneath the API SL, etc. certifications on the right hand side of the back label.
 

blackdiamond

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 Originally Posted By: speedbump47
My GC also says Wayne, NJ on the bottom left of the back. However, it also says Made in Germany underneath the API SL, etc. certifications on the right hand side of the back label.
I noticed that as well, so I would guess that it comes from Germany in drums and it put into quarts in NJ, but I have no idea.
 
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I guess what I meant was that you have the "right" version of GC, not the "US" version, by which I had assumed you meant made in the US. I actually thought those would be out of circulation, but found a few bottles of 0w30 US made Syntec mixed in on the shelves.
 
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