FAQ - GC ( German Castrol )

[m4gician]

Ouch... best price I can do while not on sale is about $7.49 a litre. Pricey a tad.

It's actually $9.44 a litre MINUS $2 a litre (if I buy 5). When I finish my stock of pennzoil platinum i'll upgrade to this stuff.

 

[steven88]

Mobil 1 0w-40

or

German Castrol 0w-30

which one do you think would be better? This is going into a modified Mazdaspeed 3 2.3L turbo...direct injection too

 

[Nederlander75]

Originally Posted By: steven88
Mobil 1 0w-40

or

German Castrol 0w-30

which one do you think would be better? This is going into a modified Mazdaspeed 3 2.3L turbo...direct injection too


Mobill 1 5w40 TDT.

 

[opposite_locker]

If price is no object, Redline 5w40.

5w40 TDT, 0w40, and GC are all fantastic oils. Another great oil that looks very comparable to GC is Mobil 1 10w30 high mileage.

If it were me, I'd use the 10w30 HM because it can be had in 5qt jugs for only $22 at WM.

 

[jesbo]

Originally Posted By: opposite_locker
If it were me, I'd use the 10w30 HM because it can be had in 5qt jugs for only $22 at WM.


M1 10W30 HM is probably a very good oil. And as long as you do not expect it to go 10K+ miles, may be OK. It has the ACEA A3 european rating - same as GC, but it does not purport to be an extended drain oil (or carry those certifications like LL-01), which is recommendeded by some manufacturers, like BMW.

If you read Mobil's web site description of the HM oil, it is described more like a prescription to cure the ills of an old, improperly maintained engine. Personally, I wouldn't use it in a lower mileage, well maintained turbo engine where I would normally use GC without reservation.

 

[steven88]

and this is all assuming for my 08 mazdaspeed 3 turbo right?

is it okay to use TDT for my engine even though its not a diesel? should I just stick with m1 0w-40 for gasoline engines instead?

 

[jesbo]

Originally Posted By: steven88
and this is all assuming for my 08 mazdaspeed 3 turbo right?

is it okay to use TDT for my engine even though its not a diesel? should I just stick with m1 0w-40 for gasoline engines instead?


I'm not an expert here, but I thought that oils designed for diesel trucks often had additives that could damage auto catalytic converters. So I'd be reluctant.

For Gasoline, turbo, DI engines, I'd go with something recommended by the MFR. GC, M1 0W40, and BMW High Performance Synthetic are all approved for my BMW 535i (twin turbo, DI), so I'd think any of them will do fine in your application. However, I would likely go with the Castrol or BMW oils before the M1, only because I've heard the M1 shears down fairly quickly. And that can be an issue in DI engines which by nature tend to have more fuel dilution in the oil.

In the end you simply have to try one and do a UOA. Only an analysis will tell you if there are any issues.

 

[Nederlander75]

Originally Posted By: steven88
and this is all assuming for my 08 mazdaspeed 3 turbo right?

is it okay to use TDT for my engine even though its not a diesel? should I just stick with m1 0w-40 for gasoline engines instead?


Its recommended for mixed fleet use so it shouldnt be an issue for the cats. I think Doug Hillary mentioned this a couple of months ago.

 

[opposite_locker]

5w40 TDT is rated "API SM", so it won't cause any harm to the catalysts in your Mazda3

Mobil 1 0w40 doea shear down to a thick 30wt (like GC) fairly quickly, but then holds its viscosity very well.

AFAIk, 10w30 HM hasn't been around very long and with the market share Mobil 1 has with 0w40, I doubt they would submit it for manufacturer approvals. I would not hesitate to run it for 10k in a car that would normally see 10k on GC or M1 0w40, but I dont think it's a good idea to run ANY oil for 10k in a turbocharged DI engine.

Use GC, 10w30 HM, or 0w40 if you want to run a thick 30wt, and 5w40 TDT if you would rather use a 40wt. Can't really go wrong with any of these oils.

 

[saaber1]

Originally Posted By: momomeister
Originally Posted By: Canawler
Originally Posted By: momomeister
Originally Posted By: Quattro Pete
Yeah, and to prevent people from putting old oil back in the bottles and returning it back to the store for full refund.

That would be lower than low.


No! Lower than low is when the store puts it back out on the shelves to resell.
I recently saw a 5qt. bottle of Q Torquepower (clear bottle) on a clearance endcap at Walmart that was 3/4 full with what was obviously used oil. Blacker than black.

And... they still wanted $10 for it.

Right now, I'm just about speechless....

I have also seen this. Bought a big jug of syntec years ago from kmart and it was used oil. It is amazing what people will do to save a few dollars.

But I suppose it could be worse. you could buy a video game system and find the box full of just rocks: http://www.geek.com/articles/games/dsi-purchase-from-wal-mart-contains-nothing-but-rocks-20090430/

 

[motts]

Relplaced Mobil 1 (10w30) with GC last week in my "02 V6 Camry.... can't feel or hear the car at idle....cannot believe the difference thusfar!!

 

[momomeister]

Originally Posted By: saaber1
Originally Posted By: momomeister
Originally Posted By: Canawler
Originally Posted By: momomeister
Originally Posted By: Quattro Pete
Yeah, and to prevent people from putting old oil back in the bottles and returning it back to the store for full refund.

That would be lower than low.


No! Lower than low is when the store puts it back out on the shelves to resell.
I recently saw a 5qt. bottle of Q Torquepower (clear bottle) on a clearance endcap at Walmart that was 3/4 full with what was obviously used oil. Blacker than black.

And... they still wanted $10 for it.

Right now, I'm just about speechless....

I have also seen this. Bought a big jug of syntec years ago from kmart and it was used oil. It is amazing what people will do to save a few dollars.

But I suppose it could be worse. you could buy a video game system and find the box full of just rocks: http://www.geek.com/articles/games/dsi-purchase-from-wal-mart-contains-nothing-but-rocks-20090430/


Wouldn't call it "amazing".. I'd call it pathetic...

 

[lexus114]

Originally Posted By: motts
Relplaced Mobil 1 (10w30) with GC last week in my "02 V6 Camry.... can't feel or hear the car at idle....cannot believe the difference thusfar!!

Yeah,it`s darn good oil thats for sure!!

 

[motts]

why??

 

[momomeister]

Originally Posted By: motts
why??


Don't you think it's pathetic that someone would refill a quart container with used oil and bring it back to the store for a refund? That's called theft.

 

[blackdiamond]

Originally Posted By: momomeister
Don't you think it's pathetic that someone would refill a quart container with used oil and bring it back to the store for a refund? That's called theft.


Someone needs to open some GC and put a few drops of green dye in it and see how long it takes for this board to go "quiet" while everyone goes hunting for the "holy grail" of motor oil!

 

[motts]

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[speedbump47]

Originally Posted By: motts
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I don't think you're reading the posts right. Someone said it was "amazing" how people tried to save a few bucks and referenced a story about a Nintendo box containing only rocks (indicating that someone bought it, replaced the contents with rocks, and returned it, only for someone else to get shafted). Momomeister responded by saying that wasn't "amazing", it was "pathetic".

 

[momomeister]

Originally Posted By: speedbump47
Originally Posted By: motts
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I don't think you're reading the posts right. Someone said it was "amazing" how people tried to save a few bucks and referenced a story about a Nintendo box containing only rocks (indicating that someone bought it, replaced the contents with rocks, and returned it, only for someone else to get shafted). Momomeister responded by saying that wasn't "amazing", it was "pathetic".


Thank you for clarifying for Motts....

 

[momomeister]

Originally Posted By: motts
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Look at the response by speedbump47..