For an engine that is producing about 110HP per cylinder, (HP/Cyl is a different and solid way of looking at an engine's load, which is what matters), oil must have adequate viscosity and high HTHS to carry the rod bearing and piston pin loads. Since many of the choices will shear, it's often best to choose an oil based on quality and high HTHS.
Let's keep in mind that most automotive engines have rod bearing sizes that are not all that far apart from each other. Sure, there are differences, but for the most part, one automotive engine won't have a 27mm rod bearing and another an absurdly large 80mm rod bearing.
The idea that some of these lower viscosity oils can provide adequate MOFT under extreme loads is generally not correct. Especially if oil temps and pressures are not actively managed.
80HP per cylinder is where 5W-40/HTHS above 3.5 and ideally 3.8 is required.
110HP per cyl really does require an HTHS pushing 5.0 and at least a 15W-50 synthetic.
Been there, done that, for 40+ years.
There is a reason I go right for M1, 15W-50 in my turbocharged builds. Take a minute and let the engine warm up with higher viscosity oils. Other than that, there is no downside.
Let's keep in mind that most automotive engines have rod bearing sizes that are not all that far apart from each other. Sure, there are differences, but for the most part, one automotive engine won't have a 27mm rod bearing and another an absurdly large 80mm rod bearing.
The idea that some of these lower viscosity oils can provide adequate MOFT under extreme loads is generally not correct. Especially if oil temps and pressures are not actively managed.
80HP per cylinder is where 5W-40/HTHS above 3.5 and ideally 3.8 is required.
110HP per cyl really does require an HTHS pushing 5.0 and at least a 15W-50 synthetic.
Been there, done that, for 40+ years.
There is a reason I go right for M1, 15W-50 in my turbocharged builds. Take a minute and let the engine warm up with higher viscosity oils. Other than that, there is no downside.