Can You Mix 5W30 and 10W30 Engine Oil? | How We Drive (2023)

FAQs

Can You Mix 5W30 and 10W30 Engine Oil? | How We Drive? ›

Yes, it is perfectly safe for you to mix 5W-30 and 10W-30 engine oils. Thanks to their close viscosity, mixing the two oils will have no damaging effect on the engine. It's worth remembering that 10W-30 has more density than 5W-30, so make sure you pour an appropriate amount when mixing.

They will mix perfectly. In warm climates, they will act very similarly. Both are the same viscosity at operating temperatures.

Typically, it is not a good idea to mix oils, though you may be able to get away with it if the grades are fairly similar (such as using a 30 grade when a 40 grade is recommended). You should never mix conventional oil with synthetic oil.

According to API motor oil guide [1], If you are using 10W–30, you can safely switch to 5W–30 (in car engines). 5W–30 is thinner than 10W–30 when cold. (you must follow the manufacturer's recommendations). However, switching from 5W–30 to economical 10W–30 is not always recommended.

You can use 10w30 instead of 5w30 as long as the vehicle isn't subjected to cold temperatures for an extended period of time. You want the oil to be pumped throughout the engine as quickly as possible after starting the engine to prevent “cold start damage”.

Thanks to their close viscosity, mixing the two oils will have no damaging effect on the engine. It's worth remembering that 10W-30 has more density than 5W-30, so make sure you pour an appropriate amount when mixing.

Yes. If it's something you do only occasionally, mixing shouldn't damage your engine. Let's say you want to top off your oil, just to keep you rolling until your next regularly scheduled maintenance check. Mixing is alright, if the oil you use is the weight (or viscosity) recommended in your owner's manual.

What Happens If You Mix Two Engine Oils? Technically speaking, mixing engine oils doesn't cause any harm to your engine, providing you follow a few simple rules of compatibility.

Thicker oil may not flow quickly enough

Its lower viscosity allows it to flow faster and fill the tiny clearances between parts, leading to a durable, consistent lubricating film. Not only that, but the engine will waste energy pumping the thicker oil, reducing fuel economy.

Many older, high mileage engines might face issues with oil pressure due to age and wear and tear. In this case, a practical method to improve oil pressure is to use a thicker oil, since the thicker oils have heavier base weight oil, which can help protect worn engine bearings well.

Is there a big difference between 5W-30 and 10W30? ›

The five and 10 digits refer to the viscosity at cooler temperatures. So, that means when you are comparing 5w30 vs. 10w30, the thinner 5w30 will circulate quicker, and flow through bearing tolerances better during an engine startup in the winter or colder climates.

10W-30 motor oil makes for a decent high-mileage oil. It gives a better fuel economy and oxidation resistance while reducing the oil consumption for older engines.

Answer: There is absolutely no need to switch to 10W-30 motor oil in the summer if 5W-30 is an acceptable grade for your engine. While some car manufacturers still advocate the use of 10W-30 (or even 10W-40) as an appropriate engine oil option for summer use, it is completely unnecessary.

Answer: If your car uses conventional motor oil, such as 5W30 or 10W30, we recommend changing the oil every 3,000 miles or 3 months. If your car uses synthetic oil, we recommend an oil change every 5,000 miles or 6 months.

Pennzoil High Mileage SAE 5W-30 Motor Oil is engineered for cars that have accumulated more than 75,000 miles, particularly those that are experiencing oil leaks and oil burn off. Engines with higher mileage tend to experience more wear than new engines.

5w30's viscosity range means it can lubricate, seal, and protect an engine's internal components in a range of climate conditions. This ability to function well both in summer and winter brings with it the convenience of not having to change oil weights with the seasons.

Can oils of different grades be mixed? The good news is that mixing different types of oil it will not harm your engine in any way in the short run. Most synthetic and semi-synthetic engine oils are based on regular oil and are compatible.

Yes. There is no danger mixing synthetic and conventional motor oil. However, conventional oil will detract from the superior performance of synthetic oil and reduce its benefits. In this post, we'll also look at if it's safe to use regular oil after synthetic oil.

While using it temporarily in a pinch likely won't cause your engine lasting harm, remember that the engineers who built your engine did so with a specific viscosity oil in mind, meaning it's best to stick with it. Some automakers do recommend different viscosities of oil depending on weather conditions.

Once you go to synthetic oil, there is no turning back. By nature, synthetic oil is far slick than regular oil, which means that it can result in leaks in a conventional engine (which are dangerous and expensive).

Can you top up engine oil without draining? ›

Adding oil instead of an oil change at this point could cause engine issues. This used oil needs to be removed to allow new oil to lubricate your engine's parts. PRO TIP Drop a drop of the used oil on the surface of water. New oil will bead up due to interfacial tension.

A few disadvantages of synthetic oil to be aware of include: Probably the most glaring downside of synthetic oil is the cost. The price of synthetic oil is around two to four times the price of conventional oil. Synthetics may be more prone to additives precipitation during cold storage conditions.

Full synthetic oil offers longer oil change intervals and prevents sludge formation in your engine. However, synthetic blend oil is more affordable, can withstand extreme temperatures, and works well for heavy-duty use. Therefore, it's often recommended if you're driving a Hyundai SUV or perform frequent tow jobs.

If you own a car that runs on synthetic oil, you're probably wondering, “How often do you change synthetic oil?” Depending on the type of car you have, most synthetic oils last between 7,500 miles and 15,000 miles. However, you'll need to check your owner's manual for more specific figures.

Yes, you can safely mix one brand of oil (e.g. Mobil 1) with a different brand (e.g. AMSOIL) or conventional oil with synthetic oil (in fact, that's what a synthetic blend is). Most synthetics today are fully compatible with conventional oils and can safely be mixed.

Monograde oils are still widely available, primarily because they're used in very hot climates, or in heavy-duty applications such as mining or construction equipment. These single-grade oils can be used in 1950s and older cars – generally SAE 30 to SAE 50 – but most owners use multi-grade.

A: Yes. This is a practical method to improve oil pressure in an older, high-mileage engine. The slightly thicker oil film from the heavier base weight oil — 10W — can help protect worn engine bearings as well.

High-mileage engines have common problems like wider gaps between components due to increased wear, the aging of seals and gaskets, which results in loss of elasticity and partial degradation, coking, and the build-up of carbon.

Synthetic oils will enhance the engine protection in older vehicles with higher mileage, just as they do for new engines.

Is 5w-30 good for old cars? ›

5w 20 and 5w 30 engine oils are commonly used in colder temperatures. However, they are recommended for older engines and light-duty use. This is because an oil with a higher rating indicates that it is thicker and suits well those engines which run hot easily.

The first number precedes the letter 'W' which stands for Winter. This measurement is related to how an oil flows when it is cold, such as at engine start-up. The second number is defined by how an oil flows at normal engine operating temperatures. The smaller the number, the better it will flow.

The Cons of 10W30 Oil

This is mainly due to the fact that it's not as thick or viscous as SAE 30. Because 10W30 motor oil doesn't have the viscosity of SAE 30, it doesn't offer quite as much protection for older engines. So, if your lawnmower or generator is getting up there in age, SAE 30 may be a better choice.

That said, you can still use 10W-30 motor oil in warm weather. But be aware that as it's a thinner oil, it might not lubricate engine parts as well as 10W-40 as temperatures continue to increase.

These oils were straight grade oils. A 10W flows well in cold weather, to protect the engine at start up, but it's is too thin for use in the summer. A 30 grade oil, thick enough to protect in the heat, was recommended for summer use.

As a general rule, you'll get the best protection in the summer when you use a slightly thicker grade of oil, such as a 10W30 instead of a 5W30. Engines need a thicker oil in the summer months because of the summer heat and its effects on thinning the oil out.

The difference, though, is in the first number—the “5” or “10” before the W. This means at below-freezing temperatures, 5W30 is generally thinner (flowier) than 10W30. They also differ in their lowest operating temperature. 5W30 will still flow at temperatures as low as -22°F, while 10W30 will only work until 0°F.

Full Synthetic motor oils in SAE 0W-20, SAE 5W-20, and SAE 5W-30 are designed to handle high internal temperatures, as well as the added external heat from summer road trips.

Mobil 1™ 10W-30 is recommended by ExxonMobil for all types of modern gasoline-powered vehicles, including high-performance turbocharged, supercharged, multi-valve fuel injected engines found in passenger cars, SUVs, light vans and light trucks.

Should I change my oil based on time or mileage? ›

However, engine oil also degrades with time, so it's just as important to change your oil when the time-based interval has been reached. The general recommendation is to change your oil every 3,000 to 5,000 miles or every three to six months, with twice a year being the minimum.

When oil has not been changed for a long time, it will begin to gel or solidify in an engine, eventually turning into sludge. When this happens, the oil will not be able to reach all parts of the engine, leading to oil starvation in the crankshafts, bearings, camshafts, and other valve train components.

You can use 10w30 instead of 5w30 as long as the vehicle isn't subjected to cold temperatures for an extended period of time.

Who needs high mileage oil? Cars with more than 75,000 on their odometer can usually benefit from high mileage oil. Older vehicles with fewer miles can benefit too, as engine seals can erode over time regardless of mileage. Degraded seals mean leaking oil, and leaking oil means your engine isn't working at its best.

Generally, 5W-30 motor oil is recommended for gasoline and light-duty diesel use. However, 5W-30 oil can handle heavy-duty use in the appropriate climate (colder temperatures). It can withstand any cold temperature and moderate pressure in winter due to its lower viscosity.

Yes. 5w30 and 10w30 are both 30 weight oils and the exact same thickness in your engine when it is at operating temperature.

In tropical weather, most OEMs still recommend multi-grade products, such as SAE 15W-40, because the lubricant flows faster through the engine than a pure SAE 40 even at higher ambient temperatures. Another important consideration when choosing an engine oil is the quality certification or performance level.

Provides proven protection for 20,000 miles between oil changes - guaranteed.

5w30 oil has a lower viscosity than 10w30, making it slightly thinner. The lower viscosity makes 5w30 a better choice in cold weather. Viscosity is the level of a liquid's resistance to flow. Thin liquids that flow easily, like water, have low viscosity.

Lol you can mix them. Now in modern engines that have super thin oil requirements, yea dont dump in 10-40 into 0-20 but a 90s truck and the fact that both 5 and 10w-30 are both approved oils for that engine its fine.

Can I mix two 5W-30 engine oil? ›

No – you shouldn't mix engine oils with different specifications like this. These two oils have contrasting viscosities and are designed for completely different types of use.

Can You Mix 5W30 with 5W40 oil? This is a common question that many people have. The answer is yes, you can mix 5w30 engine oil with 5w40 engine oil as long as the weight of the 5w30 engine oil is greater than the weight of the 5w40 engine oil.

Answer: There is absolutely no need to switch to 10W-30 motor oil in the summer if 5W-30 is an acceptable grade for your engine. While some car manufacturers still advocate the use of 10W-30 (or even 10W-40) as an appropriate engine oil option for summer use, it is completely unnecessary.

10W-30 motor oil makes for a decent high-mileage oil. It gives a better fuel economy and oxidation resistance while reducing the oil consumption for older engines.

You can add any engine oil as long as it has the right specifications — preferably with an official approval of the OEM (Original Equipment Manufacturer). Not the brand, but the specification and viscosity indicated in your car's manual are your reference for using the right oil.

Technically, you can mix SAE 30 oil and 10W30 oil, but it's generally not advised to do so. Because of the differences in the two types of oil, it's possible that blending them could damage the motor of your lawnmower or generator.

Can you use 10W-30 oil and gas in a 2-stroke engine? Of course you CAN! But it is far from the correct lubricant in a 2 cycle engine. SAE 10W-30 is far too “Thin” to provide protection in a 2 cycle engine and it also contains the wrong type of additives that will cause ash deposits and possible plug whiskering.

The second number is the high-temperature viscosity rating, measuring how well the oil protects you engine in those conditions. So, a 5W-30 or 0-W30 will give better protection in winter weather than, say, a 10W-40 or a 20W-50, while still providing solid high-temperature protection.

What happens if you use the wrong engine oil? By mistake, we put 10W40 instead of 5W30. Nothing catastrophic, the engine won't explode the moment you turn the key. HOWEVER, with the oil being too thick the engine won't have adequate protection and it'll wear out faster (especially the bearings).

Most car engines are designed to handle 5w20 oil because this type of oil flows well when the engine reaches its operating temperature of 212 degrees. If 5w30 oil is used, the engine will encounter much more resistance at this stage which is not good for it.