Oil viscosity and spec high zinc?

[gstallons]

Pete , I would contact the service department and get their blessings on changing v leaving the wrong viscosity oil in.

[Lucky Phil]

2 hours ago, pete roper said:

Took our new Hyundai in for its first oil change/10,000km service last week and they stuck a 10/30 in it rather than the 0/20 specified. My only concern was if it blows up will they honour the warranty? Since it’s all done through the ‘Official’ network they’d damn well better! I have ZERO interest in doing anything to this vehicle beyond topping up the screen washer bottle so if it shits itself and there are any issues it’ll be off to the courts toot-sweet!

Don't worry Pete, even if it does blow up which it won't they won't be smart enough to figure out if it's 20 or 30 weight anyway.

Phil

[pete roper]

2 hours ago, gstallons said:

Pete , I would contact the service department and get their blessings on changing v leaving the wrong viscosity oil in.

It’s written there on the receipt and the service book is stamped. I can think of no reason why it would cause a problem and the vehicle has an unlimited Km, seven year warranty. By the time it expires I’ll be 76 or dead! Probably the latter, so really, at the end of the day I don’t give a shit.

[audiomick]

On 9/21/2025 at 1:06 AM, Lucky Phil said:

Well just because the manufacturer tells you to run a certain grade and sometimes even a particular brand of oil doesn't mean it's the best solution. To start with manufacturers can "align" themselves with oil manufacturers ...

Add to that the fact that oil specs are changing and evolving all the time ...

So Mick I put the manufacturers recommendations on oil in the "for the guidance for the wise and the blind obedience of fools" category. 

Phil

Thanks, Phil. 

I'm aware that what is in the owner's or workshop book isn't likely to be the absolutely ideal option. Too many factors involved, and born out by having seen different recommendations for the same bike in different translations of the workshop book.

To be quite honest, I'm also not looking for the absolute best solution for each of my bikes, but rather a solution that will cover all of them adequately. The old Guzzi bulletin seems to confirm that I can get away with one weight for all three. The reason is very simple: I don't have room to be keeping supplies of different oil for each motor and gearbox, and I also honestly can't be buggered. If I can find one that fits all without any of them exploding, I'm happy.

I know that wont appeal to your engineer's sense of what is right, but I believe I'm justified in seeing myself to be following "the guidance for the wise", i.e. I consider it to be an informed decision. Hope I'm right. 

[PJPR01]

For the fools, including myself, who follow the owner's manual, but occasionally check for updates out there, and I include looking at car's as well, not just motorcycles.

So far at 60K miles of use, the Norge hasn't blown up yet due to improper oil usage!

 

Based on official documentation and owner discussions, Moto Guzzi has not changed the oil recommendation for the 2008 Norge. The manufacturer's specification has remained a high-quality 10W-60 synthetic motor oil. 

The original recommendation

At launch, the official factory recommendation for the Norge was Agip 4T full synthetic 10W-60 oil. The reasons for this specific viscosity include: 

• Air/oil-cooled engine: The air-cooled V-twin engines run hotter than liquid-cooled counterparts, and the 10W-60 weight helps the oil maintain its viscosity under high thermal stress.
• Higher film strength: The engine has specific characteristics, such as a dry clutch, that necessitate a high film strength oil for longevity. 

Updated guidance

While the fundamental recommendation has not changed, the brand of oil has. Since the original Agip oil is now more difficult to find, Moto Guzzi recommends the equivalent Castrol Edge 10W-60 synthetic for its modern big-block engines. 

Considerations for older models

Some owners of older Norge models have noticed changes in oil API (American Petroleum Institute) ratings over time. Specifically, some older formulations of Agip oil had a more desirable SG rating. Because newer formulations may have different ratings, many owners prioritize finding a quality 10W-60 synthetic oil with a higher concentration of zinc and phosphorus to protect the valve train. However, the 10W-60 viscosity remains the most critical specification. 

Edited 2 hours ago by PJPR01