I use 10w40 in my car here in Maine throughout the winter, and have no problems with it. I don't know why people are running anything thinner than that in motorcycles which generally get used in the warmer months and warmer climates...

I would suggest the use of something like AMSOIL 20W-50, you could also use 10W40. My car calls for using 5w30 in colder climates such as mine, however I let my car warm up before I go driving it around, and I've never had any problems with it. The car has been running a bit better ever since I switched. It's also a Subaru which had the usual oil leak, but the 10W-40 has stopped the leak.

I'm going to be putting 20W-50 in my bike over the winter to get it ready for next season, as long as you just let it sit there for a minute or two before taking off on it you should be fine, and I do that anyways since it's carb'd.

Just my $0.02

 

you may think it's doing fine, but cold startup is slowly destroying your bearings. the castrol 0w30 oil has superior performance across all temp and pressure ranges, and the added benefit of improved cold start flow. don't be afraid to read the information provided, hopefully you will see the light.

 

The "cold" weather weight of the oil is there to allow the oil to flow BEFORE your vehicle warms up. By the time your engine is warmed up it doesn't matter and the damage has already been done.

Beyond that, just use the weight recommended by the manufacturer based on conditions of use. They built, torture test and have to warranty the bike and know better than anyone what it should be using.

Its not rocket science.

 

that's what they're supposed to do, yes. but they don't do it well enough, and that has been shown through empirical research by people who have no skin in the game, except to find the truth. and from personal experience, i can tell you the manufacturer testing is not as thorough as we're meant to believe. just do a google search about 7mgte head gasket failures. i'm siding with science, and what a group of extremely knowledgeable engine builders have shown me. you go ahead and believe the manufacturers if you want. it's your prerogative. (just a side note, a lot of today's engines are spec-ing 0w30 oil from the get go.)

 

Why does everyone seem to ignore the manufacturer's recommendations regarding oil? If it says use 10W40 then use it! It is designed to cover a certain temperature range and as long as the temperature where you live is in the range then it should be what you use. Too much analysis goes into oil usage instead of taking manufacurers at their word. 0W-30 is far too thin for a high performance machine. At high temperatures that the cbr 600 will get to won't have the protection from a 30 weight viscosity in my opinion.

 

We all believe want to believe I tend to believe those who designed built and tested the application and in the case of our sportbikes, race in a wide range of classe, providing full technical and mechanical support under the most demanding conditions right up until full mechanical failure. Not to mention have to provide warranty and dealer/distributor support therefore putting them in the most financial risk in both practice and in buyer confidence.

But hey, if its on the net, it must be right......right?

FWIW, I've raced AMA, WERA and others over my 30+ motorcyle and auto career and have my own "testing" to fall back on.

Again its not rocket science and it doesn't take a rocket scientist to figure it out.

 

BTW, I would love to hear about the time you have spent in Japan personally observing the various manufacturers engine R&D and long term testing. Sounds fascinating.

I'm also curious as to what manufacturers are stating in print that they "would like us to believe"

Please don't say its more stuff you just Googled.

 

read the info i linked to. if you were right, my supra would have exploded by now, don't you think. are you saying that a 600 cc bike is higher performance than my 3 liter turbocharged Supra, pushing 14 psi? granted, it revs higher, but that is mainly due to reduced component weight in the engine's moving parts, and in general, does not increase engine internal pressures significantly. read the study, please. oh. and one other point: the oils advance every year, and the manufacturers recommendations are outdated very fast.

 

the 7mgte is in my car, and i can personally attest to the head gasket failures. this info was not from google. i just used that as an example of something you could use for reference. and also, how would you explain all the recalls that have occurred over the years, from all the manufacturers of motor vehicles on this planet? all that testing really stood them in good stead in those circumstances. oh yeah, those manufacturers are really looking out for us, eh? are you a climate change denier as well?

 

comparing race ready machines to street bikes is ridiculous. those engines get rebuilt at the first sign of an issue, and in some cases, after every race. apples and oranges for this discussion.