numbers on oil bottles?

Question

Does it mean the higher the number the thicker the oil?

Answer 1

The other posters did a pretty decent job. The bigger the number, the thicker the oil. These numbers are assigned according to how much will run through a standard size oriface per unit of time, and an oil that says 10W-30 is an oil that will protect in the 10 to 30 weight range. When choosing an oil it is very important to understand your engine, climate etc. A thicker oil is not always better. Some engines have very tight bearing clearances that a thicker oil cannot flow into. Thus, that bearing doesn't get lubricated and fails prematurly. The older engines had fairly large clearances. So, a 10W-40, 10W-30 would work fine, but some of the newer engines with tighter clearances can use oil as thin as 5W-30, 5W-40, 10W-20 etc. A thin oil isn't always the best either though, as it doesn't coat as well or seal the pistons as well. So, it's best to use what the owners manual/label under the hood says. BTW,15W-40 is typically a diesel oil that doesn't have the same additives that gasoline oil has. To my knowledge, Sunoco Super C 15W-40 is the only one that says it can be used in gasoline engines. Most say right on the bottle diesel engines only. Also, leave 20W-50 alone unless it's smoking alot or you're running a serious race engine etc. Most of the time with it you'll just cause unneccesary wear to the bearings as there isn't enough clearance for that thick oil to get into, but if you're a serious racer you'd rather have the better piston seal because you change the bearings every year anyway. And, if it's smoking really bad, it probably doesn't have much life left anyway. Might as well cut down on the smoke those last few miles.

Answer 2

Dear Numbers-

The numbers on the oil bottles indicate the weight of the oil. Basically how thick or as we call it the viscosity of the oil.

The oil that is used in today's vehicles is called a multigrade oil. Let me give you an example.

10w-30.

The number 10 is saying the oil will act like an "10" weight oil while it is cold meaning the oil pump can move is fairly easily to get it to the moving parts for protection.

The number "30" is telling you that once the engine has reached operating temprature the oil will protect like a heavier oil coating and protecting the parts while they are hot.

As the numbers on the bottles get larger the oil becomes thicker or more viscus. This translates to better lubricating properties inside your engine.

Also in warmer climates you can use the thicker oils to protect your engine better. In the colder climates, you can use the lighter weight oils to protect your engine better there.

If you are living here in California, I would recommend using the 10w-30 weight oil until the engine gets about 60,000 miles on it then switch to a heavier oil like 15w-40 or 20w-50.

But here is the real trick. Just keep that oil and oil filter changed every 3000 miles or 90 days, and stick with the same brand of oil. Switching brands can be a recipe for engine sludge build-up.

And just for the record the "W" stands for "winter" not weight.

Good Luck and I hope I helped you out!

Answer 3

Yes, but multigrade oils cover a range.

Answer 4

the first number i.e. 5W has to do with cold weather performance. the second number i.e. 30 refers to the kinematic viscosity(measured at 100C in units called centiStokes). There is a range of values. i.e. SAE 30 corresponds to 9.3 to 12.5 cSt.

Answer 5

You need to look in your owner's manual, it will tell you what oil you should be using depending on the climate in your area. If you lost the manual just put in 10W30 or 20W50, you can't go wrong with those.

Answer 6

yes like 10w30 10w40 20w50

Answer 7

basically, yes.