For 5w40, these values are: 12.5–16.3 mm2/s and 3.5 mPas respectively. Meanwhile, 5w40 keeps its consistency up to 50 degrees C. … 5w30 and 5w40 motor oils have the number 5 which is then followed by W. W represents winter and not weight. When it comes to grading, 5w30 has a 30 rating, whereas 5w40 has a 40 rating, and therefore it has a higher viscosity in high temperature. On the other hand, 5w-30 is a slightly more fuel-efficient option because of its lower viscosity at engine running temperature. The higher the hot grade, the thicker the oil will be when the engine is running at the optimal temperature. It is a bit thicker than 5W-40 but is still rather thin and works well to lubricate the moving parts of an engine during start-up. So, 5w30 is better than 5w40. It is recommended for use at -31°F up to 95°F / -35°C up to +35°C (outside temperature). Advertiser Disclosure. If you put in 5W-30 oil instead of 5W-20 when the latter is the grade suggested by your vehicle's manufacturer, damage to … It is also more fuel efficient. The main difference between these two types of engine oils is their thickness. At cold temperatures both of those oils have the viscosity (pretty viscous, not enough to properly lubricate the engine). On the other hand, motor oils with a greater viscosity value are luscious, thick, and tacky. 5w30 and 10w30 are those two assigned numerical numbers by SAE. When a motor oil is started, it is thicker than a 5w-30 oil. The 5W-40 Motor oil is thin motor oil that will enter the vehicle’s moving parts easily and lubricate when the machine tries to be started up. I have also tested mobil 1 5w-30 against a mixture of mobil 1 viscosities that comes … Its nice to actually see something like this on paper. But the 5w40 motor is not on their recommended list. 5W30 Oil – At lower temperatures, the viscosity of this oil remains the same. Here are the top rated 5W-30 Oils on Amazon. If motor oil is thick, then it is more viscous. As you can see, the main difference between 5W40 vs. 5W30 is the viscosity in hot weather. BMJ. Is 5w30 Better Than 5w40? Because 5w30 is thicker you are going to get a slightly lower fuel economy and slightly less horsepower out of your engine than you would with 5w20. For example, Mobil 1 5W-30 is thinner when hot than most other 5W-30 oils. The W stands for winter, and 5 is for 5 degrees Celsius, the lowest temperature at which the oil will pour. Although the 5W40 behaves like five-rated single-grade engine oil in winter conditions, it doesn’t become thinner than the 40-rated single-grade engine oil when the temperature is high. 10w40 oils work as a great solution for lubricating the moving parts of the engine while startup. This means that it creates a thinner protective film on the engine parts than the 5W40 oil, which is thicker. Reaction to high temperature. The 2nd number (30/40) pertains to the viscosity of the oil at engine operating temperatures. The oils therefore have the same viscosity in winter, which is 5 and relatively low. These codes indicated the viscosity level of certain engine oil and ‘W’ in 5w30 or 5w40 means ‘WINTER’. 5w30 and 10w30 are the recommended motor oils for Nissan automobiles. The main difference between the two is the velocity of the oils. Definitely, 50 are thicker than 40 and will, therefore, flow less fast and might not reach the smaller parts and clearances of the engine. When the ranges denoted by the numbers, oils can vary in viscosity. 10w40 oils are a bit thicker engine oils compared to 5w40 oils, with a lower viscosity of 10 and higher viscosity of 40. Main Difference between 5w30 and 5w40. This is different than an oil labelled 5W30, which has a thinner viscosity when the engine is cold at 5W. 5w40 oil is not thicker has it has a higher viscosity. 5W30 Oil – This oil has the same viscosity at lower temperatures. So, due to viscosity, 5w20 is a thinner oil during operating temperatures, whereas 5w30 is thicker during New Gear Oil Viscosity Grades: SAE 65, 70 and 75 In February 2019, the SAE J306 standard – that sets the limits for gear oil viscosity grades – has been updated. Both are multi-grade oils; however, 5w30 is thinner and faster-flowing oil, making it better suited for light-duty vehicles, while 10w30 has a thicker, slower-moving composition ideal for heavy-duty engine applications. The big difference between 5w40 and 10w30 Motor Oil is the viscosity. 5w30 oil is designed to operate at temperatures as low as -25°C, but is also a great choice for warmer climates that reach up to 25°C. What is a 5w30 Engine Oil? This is because the 5w30 motor oil has a smooth effect on the oil pump and also a more suitable flow through the engine when hot. valvoline 5w30 conventional oil vs synthetic blend. 5w30 vs 5w40 The difference between 5w30 and 5w40 is that 5w40 has a larger viscosity. 10W30 – While still quite “fluid”, this oil is a little bit thicker at low temperatures than 5W30, making the process of starting your engine a little bit harder. It has better cold-temperature performance. Mobil 1 is fine but 5w50 would be too thick for a normal NA car, a highly boost turbo like a STi would be fine though but ideal oil grade would still be a 10w40 instead of 5w50. Yes. 5w30 vs. 10w40 Toyota. It's more dependent on where you live. But in cold or freezing temperatures, 10W40 motor oil is much thicker. Dynamic viscosity is 3.5mPas. 5W30 has a lower viscosity than 5w40 and so it’s thicker. However, 10w40 is better suited for hot weather or … As a rule of thumb, thicker engine oil has a higher grade and vice versa. Instead, at room temperature, both of their thickness is same. 0w40 vs. 5w40 viscosity factors in the temperature. Tips on how to choose and to use a flat iron. When comparing the fuel efficiency of 5W30 with 5W40, 5W30 is more cost-effective than 5W40 because of its viscosity, which allows it to function with a wider range of engines. A Low-Shear-Rate Viscosity for 5w40 and 5w30; Be aware that the viscosity of 5W40 is from 12.5 to 16.3 mm2/s at 100g, while the viscosity of 5W30 is from 9.3 to 12.5 mm2/s at 100g. These oils are a bit more expensive but also more durable and will protect your engine better than the regular semi-synthetic engine oils. There is no recommendation about the 10w40 motor oil for Toyota engines, but you can still use it if you want. Both 5w30 and 5w40 are motor oil but they have different viscosity. 5W30 and 5W40 Comparison. In general, 5w30 is a great multi-grade oil for different temperature specters. You may use any brand you prefer like Castrol Edge or Mobil 1, … Also 40 weight is 40 wt. Is 5w40 thicker than 10W40? It’s thicker, uses less fuel, and is better suited to a hotter climate. The lower it is, the thicker and thinner it is. 5w30 keeps the engine running smoothly up to 30 degrees C, after which it begins to break down. Is 5W-30 thicker than 5W 40? Summary of 5w30 Vs. 5w40. The kinematic viscosity of 5w30 varies in 9.3–12.5 mm2/s range; the dynamic viscosity is 2.9 mPas. Differences Between 0W20 vs 5W30 . Posted at 05:07h in subtotal parathyroidectomy by examples of metaphors for high school students. There 3 types of engine oils in market: 1) full synthetic engine oil 5W-40 or 5W-30 (expensive) 2) Semi Synthetic engine oil 10W-40 or 10W-30 (moderate) 3) multi grade engine oil 15W-40 or 15W-30 (economy) Now that you understand oil viscosity, you probably have an idea of the difference between 5W-40 oil and 5W-30 engine oil. (low to high). The W stands for winter, and 5 is for 5 degrees Celsius, the lowest temperature at which the oil will pour. You also risk engine damage when using 5W-30 instead of 5W-20, as the internal engine components are specifically designed to be used with 5W-20 motor oil. I have tested mobil 1 5w-30 vs 0w-40 and can find no difference in milage. #15. But no it won't hurt to use 5w30. 5W-20. 5w30 and 5w40 engine oils are most commonly recommended by manufacturers. 5w30 is engine oil that has lower viscosity 5 and higher viscosity 30. 5w30 is engine oil that has lower viscosity 5 and higher viscosity 30. Each vehicle engine is manufactured around a certain engine oil grade viscosity and a specific specification. What happens if I put 5W-30 instead of 5W 20? So whereas 5w30 is a good option for cold weather, 5w40 is best to use in hot weather. 0w20 and 5w30 synthetic motor oils are suggested for Subaru engines. German engineers seem to like the ACEA A3 oils, which can be “thick “ 30 or “thin” 40 weight oils and which will have and HTHS over 3.5. 0w40 vs. 5w40 Viscosity. It is also more fuel efficient. 5w30 vs 5w40. However, it is a little bit thicker at higher temperatures than 5W20. Because 5w20 oil is less viscous, it causes less drag throughout your entire engine. The 5w40 will be thicker when warm. I tow a camper trailer in the summer and would never consider using 5w-30 with it while towing in the summer. Indeed, the type of car engine oil to use in your car can be found in the owner’s manual. If you are so concerned go to a lube center, have them flush you engine, and then ask for 5w30. Though it is thicker when compared to 5w40, it is still considered a thin oil. The oil will remain viscous at -30C, but 5w40 oil will be more effective at higher temperatures, up to 50C, as opposed to 30C, while 5w30 oil will remain viscous at -30C. You also risk engine damage when using 5W-30 instead of 5W-20, as the internal engine components are specifically designed to be used with 5W-20 motor oil. Manufacturer's Suggestion Specific information regarding the motor oil suggested by the manufacturer of your vehicle can be found in your owner's manual. To be honest, the differences are pretty negligible. 5w30 has lower viscosity hence it is suitable to use in hot or lower temperatures. Fuel Economy. But I will talk more about their differences. The answer is that they can indeed be mixed, though this shouldn’t be your preferred strategy. When you mix 5W20 and 5W30, you will be left with some of the downsides of both types of oil. That is to say that the oil you’re left with could still be quicker to freeze, while also breaking down in warm temperatures. However, a 10w40 motor oil is … It refers to the fluids’ flow, where you may describe it as thick or thin. This is why you’ll see something like this on the label: SAE 5W-30 or 0W40. At start-up, the 5w40 will be thicker than the 5w30. If 5w40 is fine for -10f cold starts then 15 would be fine for +20f. 0w30 and 5w30 are more commonplace now than they used to be. 5w40 oil is not thicker has it has a higher viscosity. For 5w40 oil: Kinematic viscosity is between 12.5-16.3mm²/s. I assume the 5w30 is thicker? A look at the thickness attribute, you see that 0w40 is the ideal option for cold temperatures. Oil Flow 5w40 and 5w30; Application 5w40 vs 5w30; And Thickness of 5w30 and 5w40; The difference between 5w30 and 5w40. As a result, the 5W30 VS 5W40 is simple to compare and is closely related to faster lubrication of the engine and metal parts. 5W30 vs. 5W40 When it comes to choosing between 5w30 and 5w40, many people prefer the former. It is a matter of location and circumstances that will lead you to prefer one oil over another. A 10w-40 motor oil is a thicker oil at startup than a 5w-30 motor oil. The 5w30 when cold will still be thicker than the 10w30 when hot anyways so it doesn't matter. It’s thicker, less fuel-efficient and more suitable for warmer climates. 5w30 vs. 5w40 Summary of 5w30 Vs. 5w40. You risk putting your engine in harm’s way by using an oil that your engine isn’t designed around. Remember, thinner motor oil (5W20) will flow through your engine better than 5W30. During winter weather, stick with 5W20 unless directed otherwise. If there isn’t an issue with you switching to 5W30, use it during the summer months. The differences between 5w30 and 5w40 oils. When compared in terms of fuel efficiency, 5w30 is more fuel economical than 5w40. The only remarkable difference that exists between the 5w20 and 5w30 engine oil is their viscosity. This means the time it will take both to flow through an orifice is different. Therefore, the 5w20 oil produces less drag and friction in the engine than 5w30 due to its thinner viscosity. An oil rated 5W-30 is a multi-viscosity oil that can be used over a range of temperatures. 5W30 at higher temperatures has a higher fluidity and a lower viscosity compared to 5w40. Also, unlike 5w30, there is no need to change the fuel if you use 0w40. It is, however, somewhat thicker than 5W20 at higher temperatures. Differences between 5w40 vs. 5w50 motor oil. Low Shear Rate Viscosity. Is 5w30 thicker than 5w20? Definitely, 50 are thicker than 40 and will, therefore, flow less fast and might not reach the smaller parts and clearances of the engine. 5W30 -vs- 10W40 To my understanding, the first number (5/10) pertains to the amount of viscosity you get when the engine / oil is cold (higher=thicker). 5W40 has a higher viscosity than 5w30 and so it is thinner compared to 5w30. Because the oils operate differently, there are variances in the fuel efficiency as well. Difference Between 10w30 And 5w30 5w30 is typically more expensive. but not longlife. The American Mobil 1 5W-30 is on the thin side, being ACEA A1 and with an HTHS of 3.09. And we will talk about all the key factors between 10w30 vs. 5w30 in this article. In your car owner manual, there is a list of recommended oil weight, whether it is a standard 5w30 vs 10w30, 10w40, 0w30 engine oil viscosity or any other. So, there is quite a bit of difference when you pit 0W-40 vs. 5W-40 motor oil. For practical purposes, recent VWs recommend 5W-40 oil. Valvoline High Mileage with MaxLife Technology SAE 5W-30 Synthetic Blend Motor Oil 5 QT (Packaging May Vary) $17.47 ($0.11/Fl Oz) Usually ships within 1 to 2 months. Castrol Edge 5W-40 A3/B4 Advanced Full Synthetic Motor Oil, 5 Quart Jug If the oil is thinner, it has a lower viscosity. You will have to choose an oil with recommended weight from a brand which displays a symbol of starburst that confirms it … Thickness. As the engine oil weight of 5w30 is heavier than 5w20, it is thicker than 5w20 and thus of more viscosity. At 100 degrees Celsius, 5w30 is going to be slightly more viscous than the 5w20. The working viscosity of 5w30 is basically from 9.3 to 12.5mm2/s whereas the operating viscosity of 5w40 is 12.5 to 16.3mm2/s. Here are the top rated 5W-30 Oils on Amazon. The sti was never intended to be a grocery getter car, its an enthusiast car. Besides, we knew that 5W40 is suitable for colder weather. If an owner wants to run a different viscosity range, all well and good - let him/her have at it - but I won't hang my butt out in the breeze and go against the engine … The 5w30 has more viscosity index improvers vs the 10w30 so technically the 10w30 would have more oil that lubricates the engine. Valvoline High Mileage with MaxLife Technology SAE 5W-30 Synthetic Blend Motor Oil 5 QT (Packaging May Vary) 4.8 out of 5 stars 12,141 $17.47 $ 17 . If you live in an area where it gets really cold then the 5w40 can become thick and may be harder for your engine to handle. On the other hand, 5w40 works smoothly in cold temperature. When looking at engine lubricants, viscosity is a critical factor. This phenomenon will be the same for 5w30 vs 5w40 oils, and the difference in viscosities will be even greater when you start the car in the morning during a NJ winter. 5w30 Vs 5w40 fuel consumption 5w30 oil ranks more in fuel economy compared to 5w40 oil. 5W30 can operate smoothly within the range of -30°c to 30°c. And based on the fuel economy, 5w30 wins the race in terms of performance. At operating temperature the 5w … Also in high temperatures, it … So, if you are driving your car in a colder place, this thin oil is the best choice for you. Living in Az, I actually use a full synthetic 5w50. The 0w40 oil is 20% thicker than the 0w30 oil, at 75 F, and certainly much too thick to be pumped throughout the engine, until it is warmed up. You can use 5W-40 because it's within spec of what the manual suggests. June 19, 2005. ... Also, Read 5w30 vs 5w40 Which Oil is the Best ... 10W-40 oil also functions well to lubricate. 5W-30 Oil vs. 5W-40 Oil. That’s just a general overview of the difference between 10w30 and 5w30. Motor oil, engine oil, or engine lubricant is any one of various substances that consist of base oils enhanced with various additives, particularly antiwear additives, detergents, dispersants, and, for multi-grade oils, viscosity index improvers. 5W30 will be more liquid and 5W40 will be more viscous. The recommended oil for all Toyota engines is 5w30 motor oil. 5w30 engine oil is suitable for both low and high temperatures while 5w40 engine oil is only suitable for warmer temperatures. Fully Synthetic 5w30 VS 5w40. Temperature. You can still use 5w40 despite the fact that it’s not listed in the recommended motor oil. On the other hand, 5w40 will not be as great as 5w30 regarding fuel consumption. For example, SAE 30 motor oil will have less viscosity than SAE 40 motor oil when they are both at 0°C but it will be more viscous at higher temperatures. Answer (1 of 21): No, your engine is designed to pump the oil recommended at full working temperature which is around 100 deg C. The fact that your air temperature is around perhaps 30 deg C is irrelevent. 2. In the case of oil flow, the 5W40 offers a higher working pressure, but on the contrary, it has a less smooth flow than 5W30. If we compare between 0W40 vs 5W30 oils, 5W30 oils are thicker than 0W40. ( 10w 40 vs 5w 40) 5w40 vs 10w40. What Is Thicker 10w40 Or 5w30? It may be used at temperatures ranging from -31°F to 95°F / -35°C to +35°C (outside temperature). On the other hand, 5w40 is engine oil has a lesser rate of viscosity. 5W40 can operate smoothly within the range of -25°c and 35°c. Which is better 5W30 or 5w40 shear rate? The lower viscosity 5w-30 oil clings to the engine’s moving parts less than the 10w-40 oil, which clings to the engine’s moving parts more than the lower viscosity 5w-40 oil. For 5w30 oil: Kinematic viscosity is between 9.3-12.5mm²/s. Is 0W40 better than 5W40? Characteristics of 5W-40 Motor Oil The 5W-40 motor oil. In this regard, the 5W40 is a little bit thicker than the average motor oil. Dec 15, 2020. If you live in an area where it gets really cold then the 5w40 can become thick and may be harder for your engine to handle. The number ‘40′ indicates that it is thicker than the average motor oil which is … The main difference between 5w30 and 5w40 is that 5w30 engine oil has a high rate of viscosity. As such, the 5W40 ranks way above any motor oil with the number 30 in terms of performance. Vs 504.00 507.00. The forty weight is a lower viscosity 40 and is know to thin out slightly. Stay with me. All you need is the right grade of engine oil for your car’s engine. The 5W30 engine oil provides a smooth flow to the oil pump. Now that we’ve covered the SAE standard and what the grades mean, we can determine the differences between 0W20 and 5W30 oil … If you are so concerned go to a lube center, have them flush you engine, and then ask for 5w30. Meaning how thick the oil gets in cold climates. It can range from 0 to 60. valvoline 5w30 conventional oil vs synthetic blend 31 Mar. 5w30 vs. 5w40 BMW 10w40 oils work as a great solution for lubricating the moving parts of the engine while startup. In order to support high mileage engines, mechanics use 5w40 motor oil. An oil rated 5W-30 is a multi-viscosity oil that can be used over a range of temperatures. So that equates that 5W40 is substantially more viscous than 5W30, which means that 5W30 is better in this regard. It all depends on what's your need. In a 5W-30, the number before the W tells you how thick and thin the oil is. Ans: No, 5w-40 oil is not thicker than 10W-40 motor oil. Motor oil's cold viscosity is important because it dictates the lubrication during the hardest part of the combustion cycle, the startup and initial ignition in gasoline engines or combustion in diesel-fueled engines. On the other hand, the 5W40 works at 12.5 mm2/s to 16.3 mm2/s. In high-performance engines, 5w40 motor oil is the best choice for use. Almost all the vehicles and SUVs of Mazda will need 0w20 motor oil. Full synthetic also tends to flow more freely when cold. The higher the number, the thicker the oil will be at room temperature (0 degrees Celsius). Share this post. 5w30 engine oil is comparatively thicker while 5w40 engine oil is less thick. NULL. For 5w30 and 5w40, the number is 5, followed by letter W, indicating “Winter.” Both 5W30 and 5W40 engine oils have precisely the same viscosity number 5 in winter, which is moderately low. 15 is only thicker when cold. Titanium wins over steel on "strength to weight ratio", but that is all. Though it is thicker when compared to 5w40, it is still considered a thin oil. Alot of us have been running Motul and Rotella 5w-40 for years. It also improved the lubrication of moving parts. ... 5w-30 in the case of modern Fords etc. 0w40 is better than 5w30 for various reasons such as performance in extreme winter, fuel economy and so on. A 5w40 motor oil is mainly used in performance engines, but you should refer to your owner’s manual about it. ... Whats the difference between 5w30 and 5w40 - some sites recommending different grades for my car ! Any 50w oil, whether 5w-50, 10w … I run 5w30 in winter and 5w-40 in summer. 5w30 works smoothly on the engine as it is thicker. Although both have the same viscosity grade in cold weather, 5W-40 is thicker than 5W-30 at warmer temperatures. Consequently, they perform better in hot temperatures. FarmerboyTdi said: I’m not disagreeing with you since it is not stated what type 15w40 oil was used but there are plenty of full synthetic 15w40 oils available. 5w30 works smoothly and regardless on high and low temperatures the high and low te. This is why it should be better to stick to the automaker’s recommendation while choosing the right oil for your car. A good engine oil isn’t necessary to be fully synthetic or expensive. Now let’s see what fully synthetic options are available when it comes to 5w30 vs 5w40. That means 5w40 has larger viscosity than 5w30. Rotella T6 5W40 may just be the “best” synthetic motor oil for a 6.0 Powerstroke as well as the best oil for your 6.0 diesel engine in almost any weather. No, in theory 5w30 and 5w40 will g ive you similar performance cold...hence 5 is the same. That's why freezing temperatures it is best to use 5Wxx so you get less friction on cold startup. Oct 2, 2010. 5w30 vs. 5w40 Mazda. valvoline 5w30 conventional oil vs synthetic blend valvoline 5w30 conventional oil vs synthetic blend. 5w30 vs. 5w40 Nissan. While 5w30 is much suitable to use in cold temperatures, the 5w40 is better for hot temperatures. However it is not much of a difference in viscosity and you should be fine. 5w40 vs 10w40 High Mileage. 5w30 vs. 5w40 Subaru. 10w40 oils are a bit thicker engine oils compared to 5w40 oils, with a lower viscosity of 10 and higher viscosity of 40. Is 5w30 Better Than 5w40? Ans: To many experts, thicker engine oils are good for high mileage. 5W40 oils test, synthetic oil test, Liqui moly 5W40 vs Castrol 5W40, Castrol 5W40 oil, Liqui Moly 5W40 oil, Liqui Moly toptec 4100 5w40, Castrol FST titaniumGreat option saddle for hardtails. Due to the increased resistance of the thicker 5W-30 oil, your engine will produce slightly lower fuel economy and horsepower output. 0w-40 is thinner at low temperatures and thicker at engine running temperature than 5w-30, but it has a wider range of temperatures it can function in. J. The number 30 means the oil will have a viscosity rating of 30 at 100 degrees Celsius. On the other hand, 5w40 is not that much thicker. The reason is, 5w30 works extremely fine with multiple engines with its lower viscosity. Their lone standout might be used with some 5w30. 5w30 implies that the specified oil has a thinner consistency in cold weather; however, it’d still perform the major function, which is to protect the engine at different temperatures, while also lubricating the moving parts to prevent friction.. (Changed yearly/8-10k miles) In my similar engine A4 (avf) I've always used the longlife 3 which is 5w 30 507 00 spec, also changed yearly. Is 5w30 good for high mileage. There are so many people on here against 5w-40, its actually surprising. The Mobil 1 5W-40 is also a European oil, though you may find it at a Mercedes dealership. 5w30 and 5w40 have comparable consistency at lower temperatures up to – 30 degrees C. However, this changes as the temperature go up. Each of these products has its own disadvantages and advantages. Lower viscosity motor oils are frequently thin and slimy, like water. Price. Check out the 5w30 vs 5w20, 5w40, 10w40 and choose the right one for your vehicle depending on the range that your car manufacturer has specified in the manual. There’s a reason why this stuff sells out at your local auto store, people. Meaning how thick the oil gets in cold climates. The number 30 means the oil will have a viscosity rating of 30 at 100 degrees Celsius. But, a 5w30 would not offer the same protection as 10w40 because it is less thick at both high and low temps. 5w30 engine oil has lower viscosity while 5w40 engine oil has higher viscosity. Which oil is thicker 5w30 or 5w40? With my old pd130 golf asz engine I used quantum platinum pd oil which is 5w 40 505 01 spec. So 5W-40 and 15W-40 both fall within the 40 range when hot, but 5W-40 is thicker than 5W-30 when hot. 0w40 vs 5w40. The average engine oil’s thickness is 30 for quite a number of vehicles. However it is not much of a difference in viscosity and you should be fine. 5W40 Motor Oil Applications But the differences do not imply that one oil is superior to the other. The thicker 5W40 is the polar opposite. I use 5W-40 for my 2014 335i which lives in the US capital region and park in a garage so super cold starts aren't a big deal. Flow. A thicker-than-average motor oil is why this is so. It’s more fuel-efficient and flows faster as well. 5w30 … Temperature. In general, 5w30 is a great multi-grade oil for different temperature specters. The longer it takes for the oil to pass through, the higher the SAE code is assigned due to the higher viscosity, which means the 5w40 has a higher viscosity than 5w30. The oil will remain viscous at -30C, but 5w40 oil will be more effective at higher temperatures, up to 50C, as opposed to 30C, while 5w30 oil will remain viscous at -30C. 5w30 oil is designed to operate at temperatures as low as -25°C, but is also a great choice for warmer climates that reach up to 25°C. Answer (1 of 2): The difference between those two oils is their viscosity at normal, running engine temperature. Dynamic viscosity is 2.9mPas. The main difference between the two is the velocity of the oils. The thicker the engine oil, the more viscous it will be and vice-versa. Differences between 5w40 vs. 5w50 motor oil. Most people prefer the 5W30 over the 5W40 for a simple reason. If all things being equal than a 0w40 oil will give you best FC but may shear due to higher amount of VII (viscosity index improver) while 10w40 will give the worst FC but more shear stable. A number represents the viscosity of the engine oil. At cold temperatures both of those oils have the viscosity (pretty viscous, not enough to properly lubricate the engine). 5w30 vs 5w40 The difference between 5w30 and 5w40 is that 5w40 has a larger viscosity. Crown Victoria 5W-30 vs. 5W-20 Pros \u0026 Cons Will 5w30 Oil Hurt My Your vehicle's engine is built and tuned to run on a specific grade of oil. W represents winter, and the number 30 describes how thick the oil will be at the operating temperature of the engine. Both 5w40 and 0w40 are great options in areas where both the warm summer and cold winter season hit. If you like to know what happens if you use 5w30 instead of 5w40 or maybe you are wondering between the 5w30 vs 5w40 which is thicker, then this is the article for you.