Hi everyone,

I have a cbr600f6 (2007) model and am doing my first oil change. I have been recommended 10w40 and 10w30, and live in the UK. Local authorised honda dealer gave me Castrol Power 1 Racing 4T 10w-30 oil to use.

My question: Which is right, and what are the pros/cons of each?

Thanks!

 

It’s my take that you use 10w-40 for hotter climates because its thicker and 10w30 for colder temperatures because its thinner. I live in a moderate temp place and I use AMSOIL 10w-30. Lowest temp is 45 and highest is 95. I have never had problem with Amsoil but I have heard good things about Castrol too. But thats my 2 cents.

 

Are you sure about that?

The 'climate' factor only affects the first number, 10W. The -30 and -40 just tell you the viscosity of the oil at hot engine temps.

To answer op's question - no discernable difference. Some people use 15W or 20W. I use Rotella T6 5W-40, I used to use a 10W-40. No big difference, just the 5W stuff was easier to get.

Most people use a 40 oil instead of a 30, but having never used that Castrol stuff, I can't comment there. If your Honda dealer recommended that stuff, it's probably fine.

 

thanks corrupt file, that's a good help. I just wonder, everyone says something different. temp in the UK rarely exceeds what, 30C but is quite warm throughout summer. My worry is with the 10w30 it could get too thin and cause clutch slip?

 

Yes i am sure. But then again correct me if I am wrong, the "W" refers to "winter." The first number is the viscosity when the oil is cold. The number after the "W" is the viscosity after being warmed by the engine to operating temperature. It is my thought that you wouldn't want thicker oil for a cold place because the engine will not warm it fast enough and parts can't slide past each other. Also you don’t want oil that is too thin because it will boil away at operating temperatures in warm or hot weather places.

 

What you are saying is correct. But if you rode in a frigid climate, you would want 0W-40, or a 5W-40 like I ride with. 10W-30 and 10W-40 are going to be virtually the same viscosity when cold, but at operating temperatures, the 30 will be a little 'runnier' than the 40. But at operating temperature, the ambient temperature does not play a role. The application determines whether a 30 or 40 oil is used, not ambient temps.

To op's question, the 10W-30 should be fine. Looks like it has some good feedback from half's Halfords | Castrol Power 1 Racing 4T 10W/30 Motorcycle Engine Oil - 4ltr

 

I see what your saying. But seeing as this is the beggining of april a thicker oil like 10w would be better than a thinner oil like 0w or 5w because the climate is about to get hotter?Correct? or I missing something?

 

For moderate temperatures like everywhere not in the arctic circle or in super hot climates, it really doesn't matter. The days of winter and summer oils are gone with the advent of multi-grade oils. I will use 5W all summer long without a problem.
Here is a chart for different ranges of different grades. For cars but the idea is the same.