10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

Motor oils are a major contributor to the efficiency of your engine. They determine how well you can handle cold weather and whether or not they give off emissions that harm air quality. 10W30 motor oil is better for standard, warm-weather driving conditions while 10W40 works best in colder temperatures such as wintertime travel with high altitudes or during other extreme climates.

Motor oils vary from low temperature (0w20) to medium grade (5w25). The different grades have differences in viscosity which affects their performance at various operating temps; therefore it’s important that drivers understand what type would be suitable under certain circumstances so there aren’t any issues down the road due to improper use!

10w30 vs 10w40, 10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

10w30 and 10w40 weights are different. 10w30 is thin and creates pressure by having many gallons of oil per pound. 10w40 is thicker, and creates less pressure but has more film strength.

Some people have the misconception that 10W-30 and 10W-40 engine oils are fundamentally different. While they both serve as low-temperature grade oil, their viscosity properties at high temperatures vary considerably.

The difference is that while a thinner motor oil such as SAE10w-30 would run too thin in warmer climates, thicker ones like those with an SAE rating of 40 will not make your car overheat even on hot days because it’s able to handle more heat without breaking down or losing its consistency.

(Skip if you don’t want to read the technical stuff)

Oil Characteristics Breakdown

There are three main components that make up the weight of an oil:

1) Viscosity Modifier – This can be made from a variety of things. The most commonly used are a variety of esters, polyglycols (DGMO, POE’s), and in the less common setups, I’ve seen butyl cellusolve.

If the MOST COMMONLY USED additive is straight esters (VI improvers) – then you’ll sometimes hear it called an “ester” oil.

2) Viscosity Index Improver – This is generally a long-chain hydrocarbon molecule or some polymer that can thicken the oil up to a point, but nothing like how they make it thick as a sludge or gel in an extreme pressure (EP) setup.

To achieve the weight and thickness of any given motor oil, this is the only other additive that you can actually SEE in the oil. WTW has VI improvers, which are long chains of molecules (they look like big black chunks). 10W30 has less of these than say 10w50 and 30wt for example will have even less.

3) Solvent – This isn’t really a “chemical”, but it’s just a hydrocarbon that allows for mixing all the other stuff together.

When you mix 10W30 and 10W40, you’ll get 20W50! When you add more VI improver to a certain weight of oils (like adding 4 quarts of 10w30 oil to 5 quarts of 10w40), you’ll be able to get thinner oil (SAE 30).

So, the difference between 10w30 and 10w40 is that they are both ester-based oils. The only real noticeable differences between them are due to the VI improvers and/or solvent (and sometimes detergents) used in the mixture. Either way, they are both thin 10w40 acts like a heavier oil than 10w30.

10w30 vs 10w40, 10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

Important Oil Characteristics

Oil viscosity is an important factor in motor oil. The colder it gets, the thinner your engine needs to be lubricated and cooled down with a “winter-grade” thicker type of oil that can withstand cold starting easier than other types given its higher level of resistance against high temperatures or even freezing conditions.

Conversely, during warmer weather when people want their car’s engines running at peak performance levels due to increased friction between moving parts such as pistons and cylinders (due to hotter aluminum surfaces).

They would need the opposite where thin oils are more appropriate because they provide better film strength properties for sealing purposes compared to thick ones which have less ability on providing this function over time under hot temperature circumstances–a key consideration when deciding what kind you should get.

The SAE J300 EOVC is the best reference to distinguishing winter from summer-grade engine oils. It grades motor oil according to its viscosity characteristics. A total of 14 high and low-temperature viscosity grades cover both monograde or single grading and multi grading oi types, with 2-3 alphanumeric codes for a given type including 10W which would be like a SAE 10 at cold temperatures but act as if it were 30 when heated up 100 degrees Fahrenheit (212 Celsius).

What IS 10W-30 Oil Exactly?

SAE 10W-30 motor oil is one of the low-temperature multi-grade oils commonly recommended by manufacturers, along with 15W-40, 5W-30, and 0W. This engine oil acts as an SAE 10 in subzero weather yet functions as a 30 when it comes to standard operating temperature. It can handle cold climates up until -22 degrees Fahrenheit (-30 Celsius).

One of the most common motor oils recommended by manufacturers is SAE 10W-30. This engine oil will act as a standard grade at normal operating temperatures, but in colder climates, it functions as a SAE10 and can be used down to -30 degrees Celsius (-22 Fahrenheit). There’s no need for worry when starting your vehicle even if you leave it outside with this type of low-temperature multi-grade oil!

10w30 vs 10w40, 10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

What Is 10W-40 Oil Exactly?

SAE 10W-40 oil is the best for cold winter days and high summer temperatures. It’s thinnest at 100°C/212°F, so it flows well but also retains its viscosity in freezing weather conditions. This helps resist thermal breakdown which means less wear on your engine components!

Performing better than an SAE 30 flow grade with similar low-temperature limits makes this type of motor oil perfect for any season or climate condition you may encounter while driving around town.

SAE 10W-40 oil does a good job of limiting wear and keeping engines warm. It has the same low-temperature limits as SAE 10W-30 but remains thicker at 100°C/212°F compared to an SAE 30 high temp flow grade, which is better for warmer weather since it resists thermal breakdown and reduces deposit formation.

10W30 And 10W40 Similarities

10W-30 and 10W-40 are two low viscosity oil grades that both contain polymers, which speed up or slow down the engine oil’s thickening rate depending on fluctuations in temperature.

They can be found as either pure conventional form or high-quality synthetic grade available to meet your needs for summer use. One of these options is fine with 10W-30 being a popular choice due to its lower cost but if you have access to higher quality motor oils like 10W-40 it’s best used during hot weather when temperatures tend to run hotter than other times of the year.

In order to keep pistons in your engine running smoothly, you might be wondering which oil grade is best for summer use. 10W-30 or 10W-40? Both are available in pure conventional form and as high-quality synthetic grades so either choice will work well; however, if you can only go with one type of motor oil it would have to be a 40 weight lubricant because the additives help maximize protection against wear while ensuring longevity.

10w30 vs 10w40, 10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

How Do I Choose: 10W30 vs 10W40

Outside Temperature

10W-30 motor oil would run smoother in colder climates while a 10W40 would be more effective in preventing engine wear and tear. The difference between the two is that 10w-30 will hold up better as it gets cold, but when you’re driving around with an ambient temperature of 90 degrees.

Fahrenheit, a heavier weight might help reduce friction for your car’s motor to operate smoothly – which means less stress on its moving parts (ex: bearings) over time.

As we all know by now cars need fuel to go anywhere so without gasoline they wouldn’t even move! But there are many different grades or octanes available at gas stations from 87 down to 93+. These refer not only to how much lead has been added but also to whether or not the fuel has a high or low octane rating.

In case you’re wondering, 87 and 89 are commonly used in off-road vehicles like motorcycles or your lawnmower while 91-93 get pumped into more everyday cars that need to run on pump gasoline.

Manufacturers Oil Recommendations

Have you ever noticed that when your car is not moving, it makes a low humming sound? That noise comes from the engine. Engine oil helps to reduce wear and tear on other internal components as well as keep things running smoothly.

It also provides lubrication for fuel injectors so they can meter out just the right amount of gasoline with each pulse at precise intervals throughout combustion cycles in order to maximize efficiency and performance without any wasted gas being expelled back into exhaust gases or used up by unburned hydrocarbons powering friction-resistant pistons and bearings during gear changes.

The manufacturer recommends what viscosity grade should be best suited for our vehicle depending on how we use it.

Engine Mileage

Oil is not just about what’s best for your engine. There are a number of other factors to consider when buying oil, including fuel efficiency and cost-effectiveness. While 10W-30 may be cheaper than the more popular 10W-40 type of motor oil.

It will also result in lower gas mileage because less energy has to go into pushing that thinner liquid compared with its thicker counterpart which can lead you back around $1 per gallon over time. Consider this tradeoff between price and performance before making any decisions on where or why an individual should buy their next quart bottle full!

API Certification

The American Petroleum Institute (API) is the first stop for any motorist looking to buy quality, safe oil. API has strict standards in place that are designed with your safety in mind and will help you make a confident decision when it comes time to purchase an engine lubricant based on what type of vehicle they drive.

The two labels worth noting most prominently are the donut symbol which indicates viscosity grade, and Starburst as this signifies not only passing SL service tests but also verifying by API itself!

Other important symbols include ACEA or JASO if recommended by the manufacturer, which are both synthetic forms of oil with different properties that when available as a choice, provide protection beyond what’s offered by conventional oils alone.

API has also established its own rating system called the Service Category System. This is designed to evaluate motor oils performance during a variety of vehicle applications and driving conditions from everyday street use to racing.

10w30 vs 10w40, 10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

Mechanics Take On Mixing 10W30 and 10W40

Some car enthusiasts may get different responses when asked about mixing these two oil types. Some say that mixing them is fine as long as you don’t live in freezing weather, while others insist on only using synthetic blends for their engine lubrication needs.

Even if you put together synthetics and conventional motor oils, they show no harm to your vehicle so long as the blend falls within a quart of one type or another per six quarts worth of total liquid volume.

However, this practice becomes dangerous when it comes to 10W-30 mixed with 10W-40 because doing so can result in decreased pressure during cornering at high revs which will cause spinning bearings (thus leading to catastrophic failure) but does not otherwise damage vehicles.

Bear in mind that mixing oils may affect your vehicle’s warranty and fuel consumption. Although both 10W-30 and 10W-40 lubricants function the same during cold startups, one is slightly thicker than the other while they are equally capable of protecting engine parts at high temperatures respectively.

Unless you are stuck where combining them is literally your only option left, avoid putting these two grades together when possible for better results or until an emergency arises without any alternative options available to use instead as a substitute.

Make sure you always have spare motor oil on hand when traveling somewhere unfamiliar with a car so that if need be, it would still work out just fine even despite not having access to its proper grade beforehand!

10w30 vs 10w40, 10W30 vs 10W40 Oil Which Do I Choose For My Vehicle?

Main Takeaways – 10W30 vs 10W40

It is difficult to choose between the two types of engine oil. However, there are many factors that go into deciding which one you should get your vehicle for use with its particular needs and climate.

The goal in choosing an appropriate type of motor oil is to find a balance where it does not interfere too much with either fuel efficiency or performance while still being able to shield against corrosion and provide adequate lubrication for safe-keeping maintenance purposes.

For those who have heavier vehicles like trucks or tractors, premium-grade might be necessary because they offer better protection from hot climates such as these more than standard grades do.

The difference between oils has less to do with temperature fluctuations but rather how well they perform during average weather conditions when used on engines depending on their weight, torque output, and displacement.

In the end, choose an oil that fits your needs best without having to pay a higher price just because of its brand or product name as they are all the same but different in their own way for what they are designed to do.

As you can see there are some differences between 10w30 vs 10w40 motor oil. Hope it was helpful for you to choose what is best for your car above info may help but please remember always consult your car manufacturer’s manual if in doubt.

Thanks for reading and stay dirty

Written by Mud Flap

Hi Im Ryne Sweeney, or, Mud Flap. I am a dedicated truck enthusiast. I like to argue how Dodges are expensive pieces of metal. One day I will start showering daily inside the house. My nights are long and my days are muddy.

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