Castrol GTX 5w-50?
#1
Castrol GTX 5w-50?
Does anyone have any experience with this oil? Its still cold here so the 5W is appealing to get oil to the moving parts quickly on start-up. It also has 50 weight properties for use in warmer climates, just as the 20-50's have. Its a full synthetic. I read where some use 5W-40 synthetic Rotella when its cool, but why not this oil year round?
#2
Join Date: Aug 2005
Location: Manningtree, England
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RE: Castrol GTX 5w-50?
People use all grades of oil with apparently good results. My take is that apart from all the other tasks oil must perform, one of the major tasks is bearing protection. To simplify this there are various types of bearing, but they either require pressure or flow depending on type. Both flow and pressure are partly dependant on viscosity. As I am sure you are aware a 5w50 will have the properties of a 5 weight oil when cold and a 50 weight oil when hot (This is not strictly true but is a simplified explanation). Now a light weight oil will flow well but provide less pressure, so it is not always a good option to just go for a light weight oil as there will not be enough pressure to maintain a sufficient film strength for pressure bearings.
With this in mind I would not use an oil of a lower weight that that specified by the engine manufacturer, as those specs will be based on the design tollerances and the type of bearings used. According to my manual for my model the lowest weight multigrade speified is a 10w-40 at below 40 deg F. I see no problem with using a 10w-50 but I would not use a 5 weight oil. there are many who do however and have no problems, but even using the wrong weight oil, no issues may arise for many miles, but it dosent mean that the oil is performing as well as a heavier oil.
My advice would be to check you manual, and maybe contact the oil manufacturer for their advice.
With this in mind I would not use an oil of a lower weight that that specified by the engine manufacturer, as those specs will be based on the design tollerances and the type of bearings used. According to my manual for my model the lowest weight multigrade speified is a 10w-40 at below 40 deg F. I see no problem with using a 10w-50 but I would not use a 5 weight oil. there are many who do however and have no problems, but even using the wrong weight oil, no issues may arise for many miles, but it dosent mean that the oil is performing as well as a heavier oil.
My advice would be to check you manual, and maybe contact the oil manufacturer for their advice.
#3
RE: Castrol GTX 5w-50?
ORIGINAL: Rockrat
Does anyone have any experience with this oil? Its still cold here so the 5W is appealing to get oil to the moving parts quickly on start-up. It also has 50 weight properties for use in warmer climates, just as the 20-50's have. Its a full synthetic. I read where some use 5W-40 synthetic Rotella when its cool, but why not this oil year round?
Does anyone have any experience with this oil? Its still cold here so the 5W is appealing to get oil to the moving parts quickly on start-up. It also has 50 weight properties for use in warmer climates, just as the 20-50's have. Its a full synthetic. I read where some use 5W-40 synthetic Rotella when its cool, but why not this oil year round?
I hope this helps
Frank From D>B>W
#4
RE: Castrol GTX 5w-50?
ORIGINAL: DRAGOSBIKEWORKS
The 5 w is where you can run cold If you going to use this oil in heat I would use 15w/50 mobil. target sell it for 5.95 a qt.it works great in cold and higher heat in the summer. On a aircooled engine I would run a 50 not 10/40 in the summer If you read what HD tells you in your book it says use oils rated at CF, CE this is diesol oil all synthetics are rated for this. A synthetic oil like 15/50 does not freeze up like std oil does and does not break down as easy as std oil. I run this oil in my bike all year no probs.15w/50 mobil one.My 2 cents.
I hope this helps
Frank From D>B>W
ORIGINAL: Rockrat
Does anyone have any experience with this oil? Its still cold here so the 5W is appealing to get oil to the moving parts quickly on start-up. It also has 50 weight properties for use in warmer climates, just as the 20-50's have. Its a full synthetic. I read where some use 5W-40 synthetic Rotella when its cool, but why not this oil year round?
Does anyone have any experience with this oil? Its still cold here so the 5W is appealing to get oil to the moving parts quickly on start-up. It also has 50 weight properties for use in warmer climates, just as the 20-50's have. Its a full synthetic. I read where some use 5W-40 synthetic Rotella when its cool, but why not this oil year round?
I hope this helps
Frank From D>B>W
#5
RE: Castrol GTX 5w-50?
I use a synthetic 5-50W, and UOA shows reduced wear over redline, and that the viscosity is holding up. I use it for the same reasons as you: pumpability. I'm very satisfied with it, and use it in all my bikes. Not saying I recommend it to anyone, just that I use it.
#6
RE: Castrol GTX 5w-50?
ORIGINAL: twiceretired
I use a synthetic 5-50W, and UOA shows reduced wear over redline, and that the viscosity is holding up. I use it for the same reasons as you: pumpability. I'm very satisfied with it, and use it in all my bikes. Not saying I recommend it to anyone, just that I use it.
I use a synthetic 5-50W, and UOA shows reduced wear over redline, and that the viscosity is holding up. I use it for the same reasons as you: pumpability. I'm very satisfied with it, and use it in all my bikes. Not saying I recommend it to anyone, just that I use it.
#7
RE: Castrol GTX 5w-50?
I switched from Redline because of extremely high wear numbers. 24X normal in copper alone. HD Shockproof also showed higher than normal wears. I'm still waiting for my third UOA so that I can get a handle on trends.
High moly levels should test out as a great boundry lubricant, and it just so happens that I got my hands on a bearing tester. Some time this weekend I'm going to go out and buy up some of the more commonly mentioned lubs here and see what they'll do. It'll just be me, in my garage, with lots of oil, but not the kind of test that you'll find on "as seen on TV". I can let you know what I learn, if you're at all interested.
High moly levels should test out as a great boundry lubricant, and it just so happens that I got my hands on a bearing tester. Some time this weekend I'm going to go out and buy up some of the more commonly mentioned lubs here and see what they'll do. It'll just be me, in my garage, with lots of oil, but not the kind of test that you'll find on "as seen on TV". I can let you know what I learn, if you're at all interested.
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#9
RE: Castrol GTX 5w-50?
Here is a reason why you don't want to use a 5wXX oil in a HD engine:
Viscosity Index Improvers
Rubber and Plastic Polymers
Start with a base of straight weight Oil. Then add a polymeric thickener. When hot, the long polymer chain is really moving around, causing the oil to flow less. When cold, the polymers stick to each other, essentially comming out of suspension. The polymers are stable up to about 210 F, where they start to break up. The drawbacks to VI polymers is that they can cause engine dirt because of their low shear strength.
However, as the shear rate increases, the shear breaks down the VI polymers, and multigrade oils have less actual viscosity at the localized high shear rate area.
The weak link is the rod bearings and Cam, in terms of rate of shear. There is less friction at the piston rings
Viscosity Index Improvers
Rubber and Plastic Polymers
Start with a base of straight weight Oil. Then add a polymeric thickener. When hot, the long polymer chain is really moving around, causing the oil to flow less. When cold, the polymers stick to each other, essentially comming out of suspension. The polymers are stable up to about 210 F, where they start to break up. The drawbacks to VI polymers is that they can cause engine dirt because of their low shear strength.
However, as the shear rate increases, the shear breaks down the VI polymers, and multigrade oils have less actual viscosity at the localized high shear rate area.
The weak link is the rod bearings and Cam, in terms of rate of shear. There is less friction at the piston rings
#10
Join Date: Aug 2005
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RE: Castrol GTX 5w-50?
Why would anyone use a specification of oil that is not condoned by either the oil manufacturer or the engine manufacturer(I'm not talking brands or dino v syn).
Like I said before I know many who will but I cannot fathom the reasoning. For my part I think (I don't know) that a 5 weight oil is far too thin for the current line up of air cooled HD's.
Now while I accept that my thoughts and ramblings on oil mean absolutly nothing because I'm no expert, and are based largely on my own feel good factor. I think that most would have to accept that both the engine manufacturer and oil manufacturer will be experts in their respective fields.
WB
Like I said before I know many who will but I cannot fathom the reasoning. For my part I think (I don't know) that a 5 weight oil is far too thin for the current line up of air cooled HD's.
Now while I accept that my thoughts and ramblings on oil mean absolutly nothing because I'm no expert, and are based largely on my own feel good factor. I think that most would have to accept that both the engine manufacturer and oil manufacturer will be experts in their respective fields.
WB