Saltydawg
Well-known member
Ok a few basics about oils.....
The major difference between a "diesel" oil and a "gas" oil is that the diesel oil contains additives designed to deal with the much higher sulfur and soot levels found in diesel engines.
The goal is to keep these small sulfur and debris particles suspended in the oil so they don't collect in the corners of your engines to cause problems later down the road.
These are commonly referred to as detergent oils (even though ALL modern motor oils have these type additives in them, in varying ammounts, diesel oils tend to have more )
Every oil manufacturer has their own little system of additives that do this job.
You want the "crud" held in suspension so it can be removed by your filter.
A single molecule of oil from Penzoil is no different than a molecule of oil from Kendall.
It's the additives that make the brands different.
When talking about oil viscosity the W means winter.
10w-30 oil......acts like a 10 weight in winter, when it's really cold, and acts like a 30 weight in warmer weather.
15w-40....again it's a 15 weight in winter and a 40 in the heat.
These are rated by the manufacturers based on a scale given to them by the SAE.
There is a little wiggle room on this scale which means not all 10 weight oils are the same thickness but they are pretty close.
Synthetic motor oils aren't really any different than regular motor oils except that they are more "pure".
Back in the old day we pulled oil out of the ground, refined it, and used it. There was still quite a bit of "extra crud" in the oil though.
Oil pulled from the ground in Pennsylvania was/is quite a bit different than oil from the middle east.
Modern science allows us to check pretty much each individual molecule and ensure it is "correct" with no extra junk.
This is what a synthetic oil is. It's oil that has undergone many extra steps to ensure it's pure and clean.
The more pure an oil is the more predictable and stable it's viscosity becomes which is why it's not uncommon to see synthetics like 0w-40.
Modern engines use a lot of aluminum and much tighter tolerances than we did 50 years ago.
This means oil viscosity has to be more predictable and stable to ensure all parts of the engine are getting the lubrication needed.
With all the modern overhead cams and complicated valvetrain setups it is very important to ensure oil can get from the bottom of the engine, where it's stored, to the top of the engine at startup, especially when it's cold out.
This is easier done with lighter weight oils which is why you are starting to see shift away from the older heavier oils.
You probably arent gonna hurt your engine by moving a little up or down the viscosity scale as long as you aren't playing in temperature extremes.
If you're from up north where it routinely gets way below freezing I would be VERY cautious running a heavier oil than your manufacturer recomends. Especially if your running a newer engine with overhead valvetrain.
Synthetic oils are expensive but they work really well if you need to worry about temperature extremes.
The major difference between a "diesel" oil and a "gas" oil is that the diesel oil contains additives designed to deal with the much higher sulfur and soot levels found in diesel engines.
The goal is to keep these small sulfur and debris particles suspended in the oil so they don't collect in the corners of your engines to cause problems later down the road.
These are commonly referred to as detergent oils (even though ALL modern motor oils have these type additives in them, in varying ammounts, diesel oils tend to have more )
Every oil manufacturer has their own little system of additives that do this job.
You want the "crud" held in suspension so it can be removed by your filter.
A single molecule of oil from Penzoil is no different than a molecule of oil from Kendall.
It's the additives that make the brands different.
When talking about oil viscosity the W means winter.
10w-30 oil......acts like a 10 weight in winter, when it's really cold, and acts like a 30 weight in warmer weather.
15w-40....again it's a 15 weight in winter and a 40 in the heat.
These are rated by the manufacturers based on a scale given to them by the SAE.
There is a little wiggle room on this scale which means not all 10 weight oils are the same thickness but they are pretty close.
Synthetic motor oils aren't really any different than regular motor oils except that they are more "pure".
Back in the old day we pulled oil out of the ground, refined it, and used it. There was still quite a bit of "extra crud" in the oil though.
Oil pulled from the ground in Pennsylvania was/is quite a bit different than oil from the middle east.
Modern science allows us to check pretty much each individual molecule and ensure it is "correct" with no extra junk.
This is what a synthetic oil is. It's oil that has undergone many extra steps to ensure it's pure and clean.
The more pure an oil is the more predictable and stable it's viscosity becomes which is why it's not uncommon to see synthetics like 0w-40.
Modern engines use a lot of aluminum and much tighter tolerances than we did 50 years ago.
This means oil viscosity has to be more predictable and stable to ensure all parts of the engine are getting the lubrication needed.
With all the modern overhead cams and complicated valvetrain setups it is very important to ensure oil can get from the bottom of the engine, where it's stored, to the top of the engine at startup, especially when it's cold out.
This is easier done with lighter weight oils which is why you are starting to see shift away from the older heavier oils.
You probably arent gonna hurt your engine by moving a little up or down the viscosity scale as long as you aren't playing in temperature extremes.
If you're from up north where it routinely gets way below freezing I would be VERY cautious running a heavier oil than your manufacturer recomends. Especially if your running a newer engine with overhead valvetrain.
Synthetic oils are expensive but they work really well if you need to worry about temperature extremes.
