Winterizing: OIL -what the numbers mean.
10-24-2014, 03:26 PM
#1
Winterizing: OIL -what the numbers mean.
Almost time to change to winter oil. For a lot of you guys this is a no-brainer but for anybody who doesn't understand the numbers and grades here's a quick post.
There are some actual temperatures involved but they escape me at the moment so we'll just say very cold and very hot.
Before multi grade oil people would put heavier oil in in the summer (30, 40, 50) which was great for summer but as temperatures drop the oil gets too thick overnight to even think about trying to crank the motor in the morning (think straight 50w oil overnight at -20).
By the same logic 10w would get way too thin driving around in the summertime.
So - multigrade oil. I'll go with 10w30, a good all around weight for an F150.
The first number (10) means that the oil won't get any thicker than straight 10 weight oil would get when it's very, very cold.
The second number (30) means that it won't get any thinner than straight 30 weight oil would get when it's very, very hot.
That's it. That's all it means. So whether you use 5w30, 10w30, 15w40 or any other variations the only time you'll actually notice is when you're out in the land of frozen in the winter time or driving through the desert in the middle of summer.
In an F150 with a V8 or inline 6 you can go a little on the thicker side because they have pretty big return passages.
With something like an import or a 4.0 Ranger, ecotech etc. you might want to be a little on the thinner side, because they have very tiny return holes. After initial cranking the other concern is having the oil be thin enough when it's still cold so that it can make it's way back to the oilpan, instead of hanging up inside the motor and starving the pump.
There are some actual temperatures involved but they escape me at the moment so we'll just say very cold and very hot.
Before multi grade oil people would put heavier oil in in the summer (30, 40, 50) which was great for summer but as temperatures drop the oil gets too thick overnight to even think about trying to crank the motor in the morning (think straight 50w oil overnight at -20).
By the same logic 10w would get way too thin driving around in the summertime.
So - multigrade oil. I'll go with 10w30, a good all around weight for an F150.
The first number (10) means that the oil won't get any thicker than straight 10 weight oil would get when it's very, very cold.
The second number (30) means that it won't get any thinner than straight 30 weight oil would get when it's very, very hot.
That's it. That's all it means. So whether you use 5w30, 10w30, 15w40 or any other variations the only time you'll actually notice is when you're out in the land of frozen in the winter time or driving through the desert in the middle of summer.
In an F150 with a V8 or inline 6 you can go a little on the thicker side because they have pretty big return passages.
With something like an import or a 4.0 Ranger, ecotech etc. you might want to be a little on the thinner side, because they have very tiny return holes. After initial cranking the other concern is having the oil be thin enough when it's still cold so that it can make it's way back to the oilpan, instead of hanging up inside the motor and starving the pump.
10-24-2014, 08:20 PM
#3
Letters are just to make it sound special. The numbers are what you need to know.
If you're interested, I've been putting Castrol GTX in everything I've owned for close to 40 years and I've never had an issue.
But as long as it's a quality brand, the most important thing is just to keep it clean. The reason it looks dirty is because there are microscopic particles suspended in the oil and those particles are what slowly eat away at your motor. Very slowly, but it adds up over time.
If you're interested, I've been putting Castrol GTX in everything I've owned for close to 40 years and I've never had an issue.
But as long as it's a quality brand, the most important thing is just to keep it clean. The reason it looks dirty is because there are microscopic particles suspended in the oil and those particles are what slowly eat away at your motor. Very slowly, but it adds up over time.
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10-25-2014, 04:54 PM
#10
Senior Member
Low oil pressure is normally from worn bearings. Going to a thicker hot viscosity oil will sometimes help, but you already know what's on the horizon (new engine) if you have low oil pressure.