Given the choice...Castrol 0w40 or GC?

[05LGTLtd]

Originally Posted By: edyvw
Originally Posted By: 05LGTLtd
I'm running 0w40 in my LGT and GC in the forester now. Was on PU 10w-30 on the LGT, but the castrol is a touch smoother/quieter. I might have to pick up some more.

GC is not as easy to source for me. Have a few oci's on hand for the forester though. Have been PP/PU fan for while but research here pushed me to try GC and BC for while at least. BOGO and sales at AAP helped some too.

I thought Forester is calling for thinner W30 oils?
Do you get worse MPG with GC?


The fozz is the spouse-mobile. I don't think she ever checks milage. She was losing a quart over an oci, so I spruced up the pcv system and went to a thicker 30wt, GC to try to see if it helped the consumption. I was ready to go to T6 before I read up on GC and got 14 quarts on sale bogo..

On the LGT, I don't bother with mpg either, just cause driving style is all over the place...

 

[edyvw]

Originally Posted By: 05LGTLtd
Originally Posted By: edyvw
Originally Posted By: 05LGTLtd
I'm running 0w40 in my LGT and GC in the forester now. Was on PU 10w-30 on the LGT, but the castrol is a touch smoother/quieter. I might have to pick up some more.

GC is not as easy to source for me. Have a few oci's on hand for the forester though. Have been PP/PU fan for while but research here pushed me to try GC and BC for while at least. BOGO and sales at AAP helped some too.

I thought Forester is calling for thinner W30 oils?
Do you get worse MPG with GC?


The fozz is the spouse-mobile. I don't think she ever checks milage. She was losing a quart over an oci, so I spruced up the pcv system and went to a thicker 30wt, GC to try to see if it helped the consumption. I was ready to go to T6 before I read up on GC and got 14 quarts on sale bogo..

On the LGT, I don't bother with mpg either, just cause driving style is all over the place...

Ah, asking because I am thinking to get Forester because I am moving to Colorado, and wife is not that confident driving in snow (she has Sentra now).
How you like the car? Any issues?

 

[05LGTLtd]

Seems to have been a good choice for us. It is darn near unstoppable in snow. A few rattles early on, tsb, and the slight oil consumption are the only issues we've had. TPMS only sees one set of wheels in our year. Hopefully they fixed that so you would be able to run winter wheels/tires with out the light on or a dealer reprogram. Not an issue for us, conti dws are good for 8-12" of the white stuff. We've got the premium with winter package. I offered to get her the limited XT, but she would not accept the auto trans. This is our third forester, and the best one yet. '14's are hitting the dealers now.. Have not looked into the new model changes much.

/BOT

 

[dgcamero]

Originally Posted By: Coprolite
So you are comparing two different winters with two different sets of tires and using the car's trip computer?


I always hand calculate my fuel economy and rely on it --- but my trip computer is less accurate with an Xw40 oil than an Xw30 oil. Yes, two different winters and two different sets of tires. Who knows if there is an actual difference? I wouldn't hesitate to use Castrol 0w40 or Castrol 0w30 oil in my car under any condition from an engine protection standpoint, but in my old-school brain, it seems reasonable to use the 0w30 for winter-ish and the 0w40 for summer-ish, to me.

 

[Coprolite]

I understand now. I don't think you can lose either way.

 

[zmelli]

0W-40WT If I can only get it at AutoZone over here in California.

I am getting up there in mileage and want to step up slightly in WT. I also think the 0W-40 may be easier on my cat.

 

[Clevy]

German castrol. It is still the SL spec which means elevated anti-wear agents. The Belgian castrol is sm/SN so I don't know what levels the 40 grades are allowed to have to meet that spec however GC has been a proven performer for years.
There are 2 oils out there that are on a pedestal in my opinion. German Castrol and M1 0w-40. They are pretty much as good as it gets. Pennzoil ultra 5w-40 is getting there but it has yet to prove itself like these oils have.

 

[Coprolite]

Clevy, given the higher limits for the 40 weights, I wouldn't be surprised if they just bumped it over the viscosity boundary to maintain basically the same add pack. Time will tell.

 

[dparm]

GC is a fine oil, but is an old and outdated formula. API SL and I haven't seen revised specs for a long time. There are oils that have much more modern formulations that I'd rather use, such as M1 0w40 or the new Castrol 0w40.

 

[threeputtpar]

Originally Posted By: Coprolite
So no one has taken this as an omen that GC is on the way out? The new replacement is BC (0w40).

I'm waiting for the first M1 vs. BC head to head thread.


I think the plan is to have BC replace GC. At all the local AAPs in my area, the shelf space that used to hold GC is gone along with the price tag.

On your other question, there was a thread a couple years ago pitting M1 0W-40 vs Edge 0W-40, although it was not US based products.

I really think that Castrol realized that M1 0W-40 has the lion's share of the European market, so they are putting out thier own 0W-40 to cash in on the name recogonition (same weight nomenclature) to boost sales versus what sales of GC were. 0W-30 is becoming more mainstream and people view it as an alternative to 5W-30, not a euro spec oil.

 

[Quattro Pete]

Originally Posted By: dparm
GC is a fine oil, but is an old and outdated formula. API SL and I haven't seen revised specs for a long time. There are oils that have much more modern formulations that I'd rather use, such as M1 0w40 or the new Castrol 0w40.

I hear this mentioned quite a bit but in reality do we have any proof that gc isnt as good as these other oils despite not being reformulated recently?

 

[Garak]

That is one thing that I wonder, too, QP. So, something like M1 0w-40 is SN (or SM up here). How many vehicles call for simply SN or SM in 0w-40? What's the point in Castrol "upgrading" GC to SM or SN? It's not going to be resource conserving so won't be used in North American or Japanese passenger vehicles anyhow, and they're certainly not going to go for dexos1 if GF-5 isn't the target market either.

 

[dparm]

My point is merely that if you can achieve the same mfg approvals (or more) with API SN, that means you have a more modern formula -- there's R&D money being spent there. GC staying API SL is, in my opinion, a sign of them just not bothering to improve it.

 

[Quattro Pete]

Originally Posted By: dparm
My point is merely that if you can achieve the same mfg approvals (or more) with API SN, that means you have a more modern formula -- there's R&D money being spent there. GC staying API SL is, in my opinion, a sign of them just not bothering to improve it.

But the API SN requirements are different for Xw-30 vs. Xw-40 grades. For Xw-30 grades, API SN limits the additive levels more severely. If GC was an Xw-40 oil, it would have most likely met API SN with it's current rich add pack. On the other hand, if M1 were to come out with a 0w-30 grade with similar add pack level as its current 0w-40, it would not meet API SN either.

 

[Garak]

Both good points. We know there was a reformulation when M1 0w-40 switched to SN. Did it need that reformulation to meet SN, though? GC, of course, as Quattro Pete points out, has the limitation of being a 0w-30 grade and faces different phosphorous limits than a 0w-40.

An HDEO 10w-30 or HDEO 0w-30 doesn't face those same limitations, but to avoid confusion, we have to remember they are CJ-4/SM or CJ-4/SN, rather than listing the SM or SN category first.

 

[bobbydavro]

Originally Posted By: dparm
GC is a fine oil, but is an old and outdated formula. API SL and I haven't seen revised specs for a long time. There are oils that have much more modern formulations that I'd rather use, such as M1 0w40 or the new Castrol 0w40.


Phos. is too high as an ILSAC grade to ever get beyond API SL. This is not a issue for the 0W-40.

The OEM specs on these products are far more of a challenge than a 120>90 micron seq IVA