Just a thought. Apart from the hydraulic lifters of the later model Califonia is there any other difference in the thrashy bits between the two? The reason I ask is, and bear with me. The PI models require 5w-40 oil so that the thin 5w can quickly operate the PI lifters. Guzzi seem happy to have the 40w bit as the hot end of the oils range. However if you have a non PI model they would like you to use 10w-60 oil. Notice they are happy to have the low of 10w this time. But why the requirement for the 60w bit? Do non PI engines get hotter? There is no reason why this should be the case. So if you have a non PI machine then it should be happy on standard 10w-40 motorcycle car? oil. The other way of looking at this is that Guzzi needed a way to shut the noise down on starting on the PI models so a 5w oil was needed and they could not find a 5w-60 on the market so had to go for a compromise using a 5w-40 possibly at the expense of engine life on the PI models. What do you think?
It’s a good question!
Don’t know the answer and suspect that those whose do may disagree with each other
I wonder who it is that specifies the oil grades for bikes and whether the advice given is affected by availability; “We have this oil in the product range and it’ll do the job”
Would be unlikely that any oil firm would do a run for a company the size of Guzzi I suppose.
Food for thought