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The second number, the 20, is the viscosity of the oil, that's the viscosity of the oil hot, so if it ends with a 20 and its hot the first number doesn't matter. the first number, 0w, is the bottom temperature at which the second number is achieved. So at zero degrees, the 0w-20 has the correct viscosity, and a 5w-20 has the correct viscosity at 5 degrees. If you live in a warm climate, it doesnt much matter, if you live in Edmonton Alberta it matters. It's also why they have block heaters. The W stands for winter. Willl a 30 viscosity hurt it, probably not, will a 40 how about a 50 or a 60? I have a European motorcycle, air cooled, that specs 10w-60 oil which is the same for a lot of non air cooled modern European cars. I am certainly not running the 10-60 in my maverick that asks for 0w-20. I would use 5w-30 in a pinch but why not just use what they say to use, when they say to use it? The more I read up on car oil the more I realized most of it is about the same, there's no real difference between Mobil One or Kirkland 0w-20 so I use the Kirkland or the Walmart oil or whatever I can get the best price on, and I change it when the car tells me to change it. Maybe short the first change because of possible contaminants, but the last motor I did that on was a 3.8 Nissan and the original oil was super clean at 5000 miles, verified by an oil analysis test. It's not 1986 anymore, the oil is not the same and the motors are for sure not the same. My Maverick only has 3500 miles on it and once I hit 15% oil life left I will plan an oil change, looks like that will be about 9000 miles, I will probably get the oil tested just for curiosity.
Moto Guzzi?
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