Can You Put Regular Motor Oil in a Diesel Engine? Read!

It actually happens to many of use. We all made mistakes by accidentally pouring gas motor oil into a diesel engine. If you’ve made this mistake before, then there is no need to be ashamed of yourself. It could be that you’ve poured some 10W-30 into the crankcase or maybe you have visited the mechanic and a newbie have done it.

At this pojnt, you might be wondering if it is going to cause an engine failure. It’s safe to say that gas oil and diesel oil is different in their own ways.

Can You Put Regular Motor Oil in a Diesel Engine?

The short answer is yes. There are some cases where diesel engines actually uses 5W-30 oil, which is known to be a common gasoline engine oil. However, we think that using synthetic oil would be a safer option. With that said, there are several newer engines that requires a special type of additives with helps with emission control and engine cleaning.

Let’s not forget that diesel engines especially pickup trucks tend to use a ton of oil. It is said that the 6.7 Cummins diesel takes up to 12 quarts, while the 7.3 powerstroke takes roughly 13 quarts. This is why it can be a bit tempting to use cheaper oils that it meant to be used for gasoline engines.

So, when it comes to using gas motor oil in a diesel engine it all varies. However, we always think it would be best to use diesel oil in diesel engines just to be on the safe side at all times.

Why Can’t Some Diesel Use Regular Motor Oil?

Can You Put Regular Motor Oil in a Diesel Engine

If the diesel engine isn’t designed to use regular motor oil, then it shouldn’t be done for a number of reasons and if you decide to do so it can lead to your engine being damaged.

Here are variety if reasons why you can’t use standard motor oil in some diesel engine.


There is no doubt that diesel engines can run a lot dirtier when compared to gasoline engines. The reason for this is because diesel fuel are known to be of lower quality, less refined and is said to contain a number of impurities.

The thing is that diesel motor oil is known to contain effective detergents that helps to clean carbon and get rid of other gunk out of the engine. Detergents are considered to be more important when it comes to modern light-duty diesels.


Let’s start by saying that detergents aren’t the only additives that you can find in modern diesel oil. It is also great to run diesel oil with cold weather additives as it helps to lubricate even on sub-zero days. It’s best to keep in mind that the viscosity of the oil declines when it is actually cold as well as its lubricating qualities.


There are cases where diesel oil contains additives to help in regards to emission. The thing is that these additives are not considered to be important to some people especially diesel truck owners.

Can You Use Diesel Motor Oil in a Gas Engine?

If you decide to use diesel motor oil in gas engine, then that should be totally fine as long as it meets the specification of the motor. All you have to do is ensure that the viscosity is correct, the thing is that you dont want to pour heavy oil in a car that should be only using lightweight oil. There are some brands on the market that actually sells dual purpose oil for both diesel and gasoline engines.


If it’s a case where you are still wondering if it is safe to use gasoline engine oil in a diesel engine, then it would best to check around in the forums to see what others are saying. You should also check the owner’s manual as it will also provide a few information on the oil type that can be used.