View Full Version : a 5 w 50 synthetic oil

3rd April 2006, 00:10
Saw it at our local crappy tire. Should be great for cold weather riders up north...or is it too thin?

3rd April 2006, 02:43
I've read your posts before and value your experience. Me, I just read a lot. So please...not looking to debate. Checked the link for Castrol and their 4-stroke oils are 10W40 and 20w50.
Just want your opinion. 5W50 auto oil OK for Bikes?

3rd April 2006, 07:38
Great debate over auto oils vs cycle oils...my thought is for discussion of the benefits of how a 5w runs at 40 degrees for a month till it hits 65 here up north. It will run like like a 20 weight thats been warmed up...so what am I missing? I have never seen a synth that covers 5 to 50 weight.

3rd April 2006, 09:23
On an engine oil rating, in this case 5W/50, the left number is the Winter number (cold temp rating) and the right number is the Summer rating.

The Summer rating normally refers to the weight of an oil not the Winter one.

In this case it is still a fairly thick oil but suitable for cold temperatures.

People normally get confused because they think the W stands for weight not Winter.

This all goes back to the original Multigrades.