View Full Version : 5w30 vs 10w30

Buck Master
04-12-2009, 03:22 PM
What's the difference and can 5w30 be used when you would normally use 10w30.

04-12-2009, 03:47 PM
it has a lower viscocity when cold which is good for initial flow and once operating temp it should be the same as 10-30 at the same temp .

first number is when the polimers are wound second is when they are unwound (roughly 100c) the 5 30 with have more polimers then the 10 30 but they are both normally detergent to combat deposits when they break down ( if i recall).

10-30 and 5-30 should both act the same at 100deg c but once they break down they revert to the intitial viscocity regardless of temp .

there is a whole bunch more that is zipping around my head but i am sure you get the idea

04-12-2009, 03:47 PM
sure. whats it in?

Buck Master
04-13-2009, 11:53 AM
sure. whats it in?
Cherokee with a 4.0L and YJ with a 4 banger

04-13-2009, 11:57 AM
*10w-30 mean , A Multi-grade oil.

*The SAE designation for multi-grade oils includes two grade numbers;as in your case , 10W-30 designates a common multi-grade oil.
Historically, the first number associated with the W (again 'W' is for Winter, not Weight) is not rated at any single temperature.

The "10W" means that this oil can be pumped by your engine as well as a single-grade SAE 10 oil can be pumped. "5W" can be pumped at a lower temperature than "10W" and "0W" can be pumped at a lower temperature than "5W".

The second number, 30, means that the viscosity of this multi-grade oil at 100°C (212°F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature.

The governing SAE standard is called SAE J300.

*A 10w30 oil is an oil that flows like a 10 weight oil but lubricates like a 30 weight. So a 10w30 and a 20w30 and a 30 all lubricate the same, but the 10 flows easier

dirka dave
04-13-2009, 12:07 PM
Simple rule of thumb....

The hotter the heavier..

IE: 5/30 winter, 10/30 summer

Buck Master
04-13-2009, 07:54 PM
So how does 10W40 compare then. Flows the same but is thinner?

04-13-2009, 08:03 PM
when cold it flows like straight 10 weight but when warm it flow as if it were 40 w oil at 100 c. (till the poymers break down then it reverts to the initial weight if i recal so guys remember to do your oil changes)