With the extreme low wear numbers being posted in the UOA section of the Castrol Magnatec, I'm seriously tempted to try it. However, Walmart does not stock it in 10W-30; just 5W-30 and 5W-20. Owner's manual for my 2000 Buick LeSabre says don't dare try using anything other than 10W-30. How much of a risk would you guys say there is running the unauthorized 5W-30 ?
The last 5W-30 vs 10W-30 thread of all time
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It will be fine...
My father ran 5W30 in my former 2000 Buick, and I continued with it. Currently the car has about 135K miles on it and is running fine.
I owned another Century many years ago that spec'd 10W30, I ran 5W30 in that as well w/o issue. I'd say go for it.
I owned another Century many years ago that spec'd 10W30, I ran 5W30 in that as well w/o issue. I'd say go for it.
Amazon does and sometimes you can get it cheap. Other times it's much higher in that grade. I got a 10w30 jug for under $18.
Originally Posted By: Merkava_4
How much of a risk would you guys say there is running the unauthorized 5W-30 ?
Merc
Unauthorized 5W-30 compared to a 10w-30. Huh ?
How is the Castrol Magnatec 5W-30 unauthorized ??
How much of a risk would you guys say there is running the unauthorized 5W-30 ?
Merc
Unauthorized 5W-30 compared to a 10w-30. Huh ?
How is the Castrol Magnatec 5W-30 unauthorized ??
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5w and 10w are both thicker than SAE 30 so I'd guess it's down to your climate and possibly a distrust of 5w30 when the manual was printed?
Merc, as an ex-military man, you know the only way is forward.
It's 15W-40 for you my friend.
It's 15W-40 for you my friend.
Originally Posted By: virginoil
How is the Castrol Magnatec 5W-30 unauthorized ??
According to my GM owner's manual, any viscosity other than 10W-30 is unauthorized.
How is the Castrol Magnatec 5W-30 unauthorized ??
According to my GM owner's manual, any viscosity other than 10W-30 is unauthorized.
Originally Posted By: Olas
5w and 10w are both thicker than SAE 30 so I'd guess it's down to your climate and possibly a distrust of 5w30 when the manual was printed?
Are you saying that they are "thicker" ?
Or they are "thicker" at elevated temperatures ?
However, the SAE30 will have high shear viscosity (aka the actual level of protection of bearings and rings and stuff) probably 10% higher than any ILSAC 30 grade.
5w and 10w are both thicker than SAE 30 so I'd guess it's down to your climate and possibly a distrust of 5w30 when the manual was printed?
Are you saying that they are "thicker" ?
Or they are "thicker" at elevated temperatures ?
However, the SAE30 will have high shear viscosity (aka the actual level of protection of bearings and rings and stuff) probably 10% higher than any ILSAC 30 grade.
Originally Posted By: SR5
Merc, as an ex-military man, you know the only way is forward.
It's 15W-40 for you my friend.
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Wonder if Walmart.com can send the 10W30 to your store for free pickup? Or does Walmart not have the 10W30's isbn# in their system? I'd try it if Castrol made it in 10W40.
Originally Posted By: Merkava_4
According to my GM owner's manual, any viscosity other than 10W-30 is unauthorized.
What, exactly, is the wording?
My owner's manual states: "SAE 5W-20 engine oil is recommended." There is nothing that says it's required.
According to my GM owner's manual, any viscosity other than 10W-30 is unauthorized.
What, exactly, is the wording?
My owner's manual states: "SAE 5W-20 engine oil is recommended." There is nothing that says it's required.
This what I found on a USA Buick Forum for 2000 to 2005 LeSabre models.
The factory recommended oil is 10w-30 and 5w-30 for colder periods.
Are we on a fishing expedition ??
The factory recommended oil is 10w-30 and 5w-30 for colder periods.
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AZjeff
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Don't do it. The slightly easier to pump at start-up oil will ruin your engine. Unless you only turn left at stoplights and park in the far right spot facing out. Then you're fine.
Originally Posted By: virginoil
Unauthorized 5W-30 compared to a 10w-30. Huh ?
I know, he's really stepping out onto a limb there, isn't he?
Merk, in Canada, I bet 5w-30 was specified for that vehicle, with allowances for even a 0w-30. Are you worried about the warranty recommendations on a 17 year old vehicle?
Following manual recommendations is fine. However, if you're making an exception and it's well reasoned, what's the concern? You have the same viscosity at operating temperatures, and the cold start part is irrelevant to you, so they're interchangeable. If you want to use 10w-30, go right ahead. If you want to try a product that isn't available in 10w-30 and is only available in 5w-30, you can do that, too.
What would you do if 10w-30 were yanked off the shelf tomorrow, junk the vehicle? As I mentioned elsewhere, Canadian Tire has yanked the bulk of 10w-30 synthetics from their shelves, and the sky hasn't fallen.
Unauthorized 5W-30 compared to a 10w-30. Huh ?
I know, he's really stepping out onto a limb there, isn't he?
Merk, in Canada, I bet 5w-30 was specified for that vehicle, with allowances for even a 0w-30. Are you worried about the warranty recommendations on a 17 year old vehicle?
Following manual recommendations is fine. However, if you're making an exception and it's well reasoned, what's the concern? You have the same viscosity at operating temperatures, and the cold start part is irrelevant to you, so they're interchangeable. If you want to use 10w-30, go right ahead. If you want to try a product that isn't available in 10w-30 and is only available in 5w-30, you can do that, too.
What would you do if 10w-30 were yanked off the shelf tomorrow, junk the vehicle? As I mentioned elsewhere, Canadian Tire has yanked the bulk of 10w-30 synthetics from their shelves, and the sky hasn't fallen.
Originally Posted By: Garak
Are you worried about the warranty recommendations on a 17 year old vehicle?
I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.
Are you worried about the warranty recommendations on a 17 year old vehicle?
I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.
Originally Posted By: Merkava_4
Originally Posted By: Garak
Are you worried about the warranty recommendations on a 17 year old vehicle?
I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.
Most likely concern about shear. Is it an older vehicle? My Jeep says the same thing but the 5w30's available when it was built were nowhere near as good as today's.
I am seriously considering the Magnatec 5w30 over the winter for my Jeep for fun. For what it's worth, the Magnatec 5w30 appears to be a bit on the thicker side than a lot of 5w30's. Based on the few specs Castrol provides I'd estimate the HTHS is close to 3.1. That is the same as many run of the mill 10w30's.
Originally Posted By: Garak
Are you worried about the warranty recommendations on a 17 year old vehicle?
I keep thinking the engineers must've had a reason for mandating 10W-30 at the time; I wonder what that reason was.
Most likely concern about shear. Is it an older vehicle? My Jeep says the same thing but the 5w30's available when it was built were nowhere near as good as today's.
I am seriously considering the Magnatec 5w30 over the winter for my Jeep for fun. For what it's worth, the Magnatec 5w30 appears to be a bit on the thicker side than a lot of 5w30's. Based on the few specs Castrol provides I'd estimate the HTHS is close to 3.1. That is the same as many run of the mill 10w30's.
Originally Posted By: Merkava_4
How much of a risk would you guys say there is running the unauthorized 5W-30 ?
Instant
How much of a risk would you guys say there is running the unauthorized 5W-30 ?
Instant
Both. At the exact same time.
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