5w50 vs 10w40 engine oil differences

Should I buy 5W-50 or 10W-40 oil for my car’s engine? The answer to this question usually varies based on several different key factors.

Therefore, it is important that you do your research before buying any type of motor oil for your car. With that being said, here are 3 things you need to know before you can make the right choice.

When doing so, the first thing you should do is to look in your car user’s manual. Every car has one, but if haven’t one, search it on the internet, you should find it.

Every manual contains in-depth information about the type of engine oil the manufacturer recommends. If you don’t find one or any of these two oils that we are talking about, then don’t use them at all.

Viscosity index15156
Viscosity grade5040
Recommended UseHigh-performance engines, extreme temperaturesGeneral purpose, moderate temperatures
Protection at high temperaturesGoodModerate
Protection at low temperaturesModerateGood

Differences Between 5W-50 and 10W-40 Engine Oil

When you do your research, you will most likely find that there are a number of key differences between using 5W-50 and 10W-40 engine oil. Some of the most noteworthy have been listed for you below.

5W-50 Engine Oil

One of the first things that you need to consider is the type of engine oil that is best for your vehicle’s performance, particularly in climates that are known for having high temperatures.

For example, it is highly recommended that you use 5W-50 for performance engines including those that have been listed in the following section.

  • Shelby GT 500 and Ford GT, and Focus RS cars, which are popular 5.4l supercharged applications
  • Range Rover Engines (i.e.years 2001 – 2002)

The driver of these types of performance cars will also tend to pay more in cost for their oil changes, especially since the 5W-50 is more expensive to buy than the 10W-40 engine oil.

It is also important to note that the 5W-50 oil is a lot more dependable than the 10W-40 engine oil. This is primarily because 5W- 50 engine oil is a full synthetic oil with a higher viscosity index.

And, the length of its life is dependent upon the mileage that is driven between oil changes.

10W-40 Engine Oil

Unlike the 50W-50 engine oil and its tight relationship to cars classed as performance engines like Shelby GT and Ford GT cars, the 10W-40 engine oil is highly recommended for other engine types, including the following:

This is mainly because the 10W-40 engine oil is made up of a combination of conventional high-quality based engine oil, synthetic oil, and modern-day performance additives.

Therefore, when you purchase 10W-40 engine oil instead of 50W-50, you are normally looking for engine oil that provides superior performance in cars that have at least 75,000 miles or more on them.

5W-505WA3/B4SNMAGF-5BMW, Mercedes-Benz, Porsche, VolkswagenHigh
10W-4010WA3/B3SNMA2GF-4General use, not specific approvalsMedium

Similarities in 5W-50 and 10W-40 Oil

As with most of today’s vehicle engine oils on the market today, you need to know that there are certain similarities that should be considered, too.

For instance, both the 5W-50 and the 10W-40 oils are both known as winter motor oils. However, because of their properties, they are both considered to be ineffective whenever the car is operating in freezing temperatures.

What to choose?

If you are looking for the best engine oil that you can buy between the 5W-50 and the 10W-40 Oil, there are some factors that you need to consider first including the following:

Class of the Vehicle’s engine – high-performance cars

The age of the engine – i.e. 10W-40 is an excellent choice for older cars, particularly those that have at least 75,000 or more on them

  • Cost of the engine oil, particularly if you can avoid paying the much higher cost.
  • Temperatures: Cold Temperatures without the excessive freezing below temps

Whatever the case, you need to make your decision best on your owner’s manual and the factors that are provided for you above.


There are both similarities and differences in selecting the best car engine oil on the market today for your vehicle. So, you will need to review each engine oil before you make your decision to buy.

Typically, if you are driving a high-performance car like the Shelby GT, the best option for you is the 50W-50. On the other hand, if you driving an older car with an extended number of miles on the vehicle, your best option is 10W-40 engine oil for your vehicle.

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