10W-40, 5W-40 | Engine Oils

Huge selection of motor oil from many manufacturers. You have the choice!

Among all lubricants and fuels in the car, engine oil is of particular importance. As the central link between mechanical friction and power generation, the engine oil plays a decisive role in the transmission of power from the engine in the car and is therefore exposed to various loads during each individual journey. If one considers that the intervals between oil changes are sometimes as short as 30,000 km, the importance of engine oil quality becomes even clearer.

Engine oils can essentially be distinguished by their viscosity, their manufacturer's approval or recommendation, and their basic chemical structure. Usually the viscosity is specified in an SAE class. In modern passenger cars, multi-grade engine oils are used which are capable of exhibiting different viscosities in the cold state, such as when the vehicle is cold-started, and in the warm state, i.e. at regular operating temperature up to the maximum load. This is a significant advantage, as an engine oil is thus able to ensure the rapid lubrication of an engine during a cold start with the highest possible flowability, thus guaranteeing qualitative aggregate protection, while at the same time offering a higher viscosity at high operating temperatures in order to be able to maintain a reliable lubricating film under heavy loads. Widely used viscosity grades in cars are SAE 0W-30, 5W-30 and 5W-40, which have replaced the once dominant viscosity 10W-40. An engine oil with a viscosity of 0W-30 is more fluid in comparison to the 5W-30 engine oil when cold and is therefore able to oil the engine more quickly and build up a protective lubricating film more quickly. In addition to the viscosity, automobile manufacturers limit the quality requirements for an engine oil to be used more precisely by specifications or so-called manufacturer's approvals. Common specifications are defined by the manufacturer-independent institutions ACEA (Association des Constructeurs Européens d'Automobiles), the API (American Petroleum Institute) or the ILSAC (International Lubricants Standardization and Approval Committee). Lubricant manufacturers can produce their products according to the classes defined in each case, such as ACEA A3/B4, API SN or ILSAC GF-5, while automotive manufacturers define which specifications must be met for the various vehicles. By specifying an engine oil specification, it is possible to identify in particular whether an engine oil is suitable only for petrol engines or also for vehicles with diesel engines. In the case of requirements for a lubricant individually defined by the vehicle manufacturer, a standardised specification is replaced by the so-called manufacturer approval or operating instructions. An approval is issued directly by the vehicle manufacturer. Oil manufacturers use it to produce products that meet the technical requirements of such an approval. Some of these products are then licensed and officially approved by the car manufacturer (in our online shop, the approvals of an engine oil  are listed in the product details under "approvals:") or recommended by the lubricant manufacturer as being suitable for use in vehicles that require an engine oil of the respective operating regulation (in our online shop, these are delimited from the manufacturer releases as "recommendations"). The most popular operating regulations defined by the automobile manufacturers include BMW Longlife-01, Mercedes-Benz MB 229.52, VW 505 00 and 507 00 or GM dexos2. However, there are also various other approvals from the vehicle manufacturers BMW, Mercedes, VW, Ford, Chrysler and many others.

In ATO24's online shop, you will find products from well-known lubricant manufacturers as well as a wide range of OEM products with which car manufacturers sell lubricants under their own brand. Due to our wide range of products we are able to provide the right motor oil for almost every vehicle - at a reasonable price and with short delivery time, no matter if European, American, Asian vehicle, passenger car, SUV, sports car or super sports car.

What does 5W-40 mean?

The designation 5W-40 indicates the viscosity of your engine oil in a so-called SAE class. Briefly explained, there are two components of the specification: The number before the W stands for the viscosity of the engine oil in winter (index W) or in cold condition. The other index number refers to the fluidity in warm or operating condition.

A 5W-40 and a 5W-30 engine oil therefore have the same flowability at cold start. At operating temperature, a 5W-40 oil is more viscous. In order to be able to evaluate these characteristics for their effect on the protection of the engine, always the individual case is to be lit up.

Buy the right 5W-40 online at ATO24!

With a wide selection of 5W-40 oils, the online store of ATO24 certainly has a suitable 5W-40 engine oil for your car ready. Simply orient yourself to the required specifications or approvals / recommendations, which the manufacturer of your vehicle prescribes. You can find this manufacturer information in your vehicle manual.

Often a 5W-40 engine oil is required in combination with the following releases / recommendations or specifications:

• Buy 5W-40 API SN engine oil
• Buy 5W-40 ACEA A3/B4 engine oil
• Buy 5W-40 BMW Longlife-04 engine oil
• Buy 5W-40 Mercedes-Benz MB 229.51 engine oil
• Buy 5W-40 VW 505 00 Engine Oil for Volkswagen / Audi / Skoda / Seat

5W-40 oil from OEM: Mercedes-Benz, Toyota, Nissan, Volvo and more.

In addition to products from internationally known oil brands, you can also find OEM products from vehicle manufacturers at ATO24. Often, these are also explicitly tailored to the characteristics of the engines of this one manufacturer and / or it is the products with which your vehicle is filled from the factory (so-called first fill). You have the choice:

• Mercedes-Benz 5W-40 engine oil
• Toyota 5W-40 engine oil
• Nissan 5W-40 engine oil
• Volvo 5W-40 engine oil

Mix 5W-30 and 5W-40?

In principle, you may mix a 5W-30 and a 5W-40 engine oil - for example, if your engine has too little oil available and you do not have any engine oil in the correct viscosity at hand. In any case, you should make sure that specifications and approvals are adhered to in addition to the viscosity.

In the long run, mixing 5W-30 and 5W-40 engine oil is suboptimal because, depending on the mixing ratio, the actual viscosity of your engine oil will approach the mixed oil.

Buy 10W-40 Oil: Huge selection, top prices

In the ATO24 online store you get exactly the right 10W-40 engine oil for your vehicle! In addition to top prices, we offer you reliable advice and help you find the right 10W-40 oil.

The viscosity SAE 10W-40 belongs next to 5W-30 to the most demanded engine oil viscosity. But what exactly does 10W-40 actually mean and why are there so many different oils despite the same viscosity? We will clarify these and other questions in the course of this blog article.

What does 10W-40 mean?

10W40 stands for a multigrade viscosity. Correctly written out as 10W-40, the two viscosity indexes given, 10W and 40, refer to all-season use (suitability for winter and summer use). These multigrade oils were developed over 50 years ago and were intended to replace the procedure of having to change oil at summer and winter time. The viscosity specification in cold (10W) and warm (40) viscosity indicates the oil's flowability at high and low temperatures.

10W stands for the flowability in winter (this is where the W index comes from). The value 10 is not a directly measurable value of a certain unit but an index number. The lower the number before the W, the better the flowability at cold temperatures and cold starts. A 5W-30 engine oil therefore has better flow properties in cold conditions than a 10W-40 engine oil.

The number 40 stands for the flowability of the oil at a temperature of 100 degrees Celsius. Again, the lower the number, the lower the viscosity at a temperature of 100 degrees. Accordingly, a 10w40 engine oil is more viscous than a 0W-30 engine oil.

Buy 10W-40: Here's what to keep in mind!

Even if the vehicle manual recommends a 10w-40 engine oil, the right 10W40 oil is not immediately found. When buying a 10W-40, attention must be paid to the prescribed specification and release. They represent the particular chemical properties of an oil.

10W-40 engine oil approvals

As always, your vehicle may require a release in addition to the 10W-40 viscosity. These approvals are listed on the bottle label next to the specifications. The best known approvals are those of BMW (e.g. LL-04), VW (e.g. VW 507 00) and Mercedes Benz (e.g. MB 251.0). The approvals with the engine oil are comparable with a quality seal of the automobile manufacturers. Thus this manufacturer issues a certain chemical characteristic of oils, which must be fulfilled, in order to be permissible for the cars from the own product series.

What engine oil approvals occur together with viscosity SAE 10W-40? Among many others, are common engine oils of the following releases and recommendations 10W-40 engine oils:

• BMW Special Oil 10W-40 Engine Oil
• Mercedes-Benz MB 229.1 10W-40 Engine Oil
• VW 505 00 10W-40 Engine Oil

What is the difference between 10W-30 and 10W-40?

Both viscosities share the winter property "10W", which means that they have the same properties at low temperatures and cold start. The indices 30 and 40 refer to a difference at high temperatures. Thus, the 10W-40 shows a slightly higher viscosity at high operating temperatures. This difference can be advantageous if the engine has oil losses with a 10W-30 motor oil.