Originally Posted By: bchannell
I had a question about all this 'thinner vs thicker" thing.
If VVT and the others are designed for a specific viscosity, how does it hold water that you can't use a high vis oil such as a Toyota that specs 0w20 and you use a 5w30? Some of these very oils have true "measured" viscoisty that overlap quite a bit and also others are so close that they would fall into the normal distribution of statistics. So, how could this cause a problem?
Now, if you're talking going from 0w20 to 15w40 or 20w50 then maybe so.
Also, if it makes a difference, then why does Toyota specifically say in their manuals that ~"higher viscosity may be used if you encounter heavy duty conditions". It's ok to screw up valve timing on engines that are towing or in high heat?
I don't mind using 0w20, but I do have to wonder if it really matters much. There's an awful lot of cars using thin oil and not blowing up.
Vvt-I functions are not controlled by viscosity, it is controlled by the computer management system opening and closing g control systems. it is cycled/actuated by hydraulic pressure, which works with hudraulic pressure moving the cam wheels in desired directions to adjust timing advance, and retard in concert with the ignition system and fuel mapping. Since liquid is incompressable it happens quickly with either 60cst or 6cst actual viscosity.
For most day to day use a 0w20 is adequate. My problem is with the untested deposit protection on the viscosity, not the viscosity itself. For most drivers needs this viscosity is adequate, I just think the oil is formulated inadequately.
Now if you are driving high speed, towing or doing other severe duty I think that a higher viscosity is smart. Higher engine loads and speeds (usually from higher rpms) will benefit from an oil with a higher HTHS. There are formulations such as acea a3 that provide more protection, not only with viscosity, but with formulation that promotes better boundary and deposit protection.
I had a question about all this 'thinner vs thicker" thing.
If VVT and the others are designed for a specific viscosity, how does it hold water that you can't use a high vis oil such as a Toyota that specs 0w20 and you use a 5w30? Some of these very oils have true "measured" viscoisty that overlap quite a bit and also others are so close that they would fall into the normal distribution of statistics. So, how could this cause a problem?
Now, if you're talking going from 0w20 to 15w40 or 20w50 then maybe so.
Also, if it makes a difference, then why does Toyota specifically say in their manuals that ~"higher viscosity may be used if you encounter heavy duty conditions". It's ok to screw up valve timing on engines that are towing or in high heat?
I don't mind using 0w20, but I do have to wonder if it really matters much. There's an awful lot of cars using thin oil and not blowing up.
Vvt-I functions are not controlled by viscosity, it is controlled by the computer management system opening and closing g control systems. it is cycled/actuated by hydraulic pressure, which works with hudraulic pressure moving the cam wheels in desired directions to adjust timing advance, and retard in concert with the ignition system and fuel mapping. Since liquid is incompressable it happens quickly with either 60cst or 6cst actual viscosity.
For most day to day use a 0w20 is adequate. My problem is with the untested deposit protection on the viscosity, not the viscosity itself. For most drivers needs this viscosity is adequate, I just think the oil is formulated inadequately.
Now if you are driving high speed, towing or doing other severe duty I think that a higher viscosity is smart. Higher engine loads and speeds (usually from higher rpms) will benefit from an oil with a higher HTHS. There are formulations such as acea a3 that provide more protection, not only with viscosity, but with formulation that promotes better boundary and deposit protection.
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