Looks like you need an engine oil top-up.
Should be pretty straightforward, right?
You’re probably asking yourself, “what oil does my car take?”
Or maybe, “Can I mix motor oil types?”
This Article Contains
- What Oil Does My Car Take?
- What Influences My Motor Oil Selection?
- 5 Engine Oil FAQs
Let’s dive in.
What Oil Does My Car Take?
And your best guide to selecting an engine oil is the vehicle owner’s manual.
Remember, the owner’s manual:
- Will define the engine oil viscosity and type that the car manufacturer recommends
- May include details for cold or hot climate and seasonal use
- May include alternative-weight oils if you can’t get hold of the exact product needed
But what can you do if the manual is missing?
There are still answers to be found:
- The oil-filler cap on top of your engine may list the viscosity rating.
- The car manufacturer may apply a small decal under the hood, noting the viscosity grade needed.
- You can check with your vehicle dealership for its engine oil recommendation.
- The oil section in a parts store sometimes has a chart listing vehicle makes and models and the right oil for them.
- Some oil companies offer online databases to search for the right oil for your vehicle’s make and model.
And if all these don’t yield any answers, you can still consult a professional mechanic for help.
Next, let’s get into some detail regarding motor oil selection.
What Influences My Motor Oil Selection?
Here’s a look at some elements to consider when selecting your engine oil:
1. Engine Oil Viscosity
Engine oil viscosity (or oil weight) is the most crucial factor and has a format like “5W-30.”
Viscosity represents an oil’s ability to flow at different temperatures.
Engine oil becomes thinner when it heats up and thickens as it cools.
Thicker oil generally provides a better lubricating film between the moving engine parts. However, the excessive thickness can make it hard to crank the car as the engine needs more energy to move its parts, reducing fuel economy.
Thinner oil may flow better but might not offer enough protection for vital moving components.
Motor oils may have additives to reduce their tendency to thicken or thin with changing temperatures. Additives also provide other features like foam inhibitors.
2. Climate And Seasons
Modern engine oils can cover a wide range of operating temperatures.
However, there are situations where certain oil grades perform better.
Hotter climates may require oils that can resist excessive thinning (like 10W-40), while colder regions might demand an oil that won’t thicken easily at lower temperatures (like 5W-30).
You may also need to change your engine oil from summer to winter.
3. Driving Habits And Conditions
Rugged driving conditions like off-roading or towing requires the motor oil to work harder with a more frequent oil change service. This might call for motor oil with additives that help reduce engine friction under high temperatures and heavy loads.
Short trips under 15 minutes may not allow your engine to reach maximum operating temperature consistently, meaning water condensation won’t evaporate, resulting in sludge build-up. In this case, you may need an engine oil with additives that prevent sludge formation.
4. Engine Age
Newer cars with multi-valve, high-rev engines typically demand a thinner oil to prevent start-up damage. In contrast, an older engine in a classic ride likely wants a thicker oil for correct oil pressure between worn engine parts.
We’ve gotten down the basics of how to figure out what oil your car takes.
Now, let’s answer some FAQs.
5 Engine Oil FAQs
Here are some questions regarding engine oil use and their answers:
1. What Do Motor Oil Viscosity Ratings Mean?
The SAE (Society of Automotive Engineers) viscosity rating, or viscosity grade, represents motor oil’s fluidity and performance at high and low temperatures. The typical format will be something like 5W-30.
The first number preceding the W (which stands for Winter) typically represents the oil’s thickness at 0OF (-17.8OC). Lower numbers mean the oil runs freer in cold weather.
For example, 0W-20 can flow better at low temperatures than 10W-30.
The second number represents the oil’s characteristics at running temperatures and is usually rated around 212OF (100OC). The higher this second number, the more resistant the car oil is to thinning. For example, 10W-40 is thicker at higher temperatures than 10W-30.
Viscosity ratings apply across all types of motor oil, whether traditional oil or synthetic oil. And the most common oil you’ll find in modern cars is the 5W-30 or 10W-30.
2. What Do Motor Oil Labels Mean?
Reputable engine oils will usually have the API (American Petroleum Institute) donut and the API starburst symbol on their bottles.
The API donut should display:
- The SAE viscosity rating (this will be the usual 5W-30, 0W-20, etc.)
- A service designation on the container (showing letters like SN, SP, CK-4)
- Indication if the oil has passed the Resource Conserving test
API’s latest service standards are “SP” for gasoline (petrol) engines and “CK-4” for the diesel engine. An older engine might be perfectly content with motor oil with an API service rating of “SG,” but newer cars may need “SP.”
The API starburst symbol indicates the engine oil has passed the service tests listed in the API donut. An oil stating that it “meets” an API service standard isn’t the same as one that’s actually registered and tested to ensure compliance.
3. What Are The Types of Motor Oil?
Motor oils are made of a base oil and additives.
Base oils are derived from crude oil or natural gas and typically make up 70-90% of engine oil. The remaining 10-30% are additives, which perform several functions, including optimizing oil consumption and keeping the car’s engine corrosion-free.
You’ll typically find four types of motor oil on store shelves:
A. Conventional Motor Oil
Conventional motor oil is a product of refined crude oil and is the cheapest type of engine oil. It’s also referred to as mineral oil or organic oil. It’s suited to light-duty newer cars with simple engines and low to average mileage.
Conventional oil degrades faster than other types, so getting a conventional oil change every 4,000 miles or 4 months is advisable. Or, follow the guidance of your oil-change indicator if your vehicle has one, and don’t forget to get the oil filter changed too.
B. Synthetic Motor Oil
Synthetic motor oil provides higher viscosity levels, is resistant to thermal breakdown, oxidation, and oil sludge formation, with improved fuel efficiency.
Synthetic oil works for high-performance vehicles that demand high levels of lubrication. However, it can cost 2-4 times more than conventional oil.
Even with its improved performance, you’ll still need a synthetic oil change, usually within 7,500-10,000 miles. Make sure to pay attention to your oil-change indicator or follow the manufacturer’s recommendation.
C. Synthetic Blend Motor Oil
Synthetic blend motor oil combines conventional oil with synthetic oil base stocks with some additives. It has many full synthetic oil characteristics but has a lower price.
If you’ve been thinking of switching from conventional oil, but are deterred by the price of full synthetic oil, then a synthetic blend oil might be a good option.
D. High Mileage Oil
If your vehicle has clocked more than 75,000 miles, then high mileage oil might be the oil for you. This oil is designed to reduce oil consumption and minimize oil leak and oil seepage issues.
High mileage oil can also help cut smoke and emissions in an older engine and can be formulated from conventional, synthetic blend, or full synthetic motor oil.
4. Can I Mix Different Motor Oil Types?
Yes, you can, but it’s not advisable.
All API oil types are required to be compatible with one another.
Adding a regular oil (conventional oil) to a synthetic oil won’t harm either. However, mixing will reduce the benefits of additives in the synthetic oil.
It’s best to avoid mixing car oil types to maintain the maximum benefits of the better oil formulation.
5. What Should I Do If I Have To Mix Different Motor Oils?
There may be times when you simply can’t find the exact engine oil you need.
Here’s what you can do:
First, choose an oil from the same manufacturer as your current car’s oil. If not possible, then pick one with the same API Donut certification.
Secondly, select a product with similar chemical and performance characteristics to what’s in your vehicle’s engine.
Here’s an example:
Say your current car’s oil is a regular oil with viscosity 20W-50, API SM, and you need to top up the oil level. Adding a 10W-40 oil to the 20W-50 in the car’s engine would reduce the overall viscosity.
It’s not recommended unless in an emergency after which, you’d need a full oil change service.
Choosing the right oil for your car can be confusing, and using the wrong oil could end in costly engine repairs. When in doubt, always consult the manufacturer’s manual and keep up with regular oil changes.
And if there isn’t a manual, there are other ways to get answers, including getting a mechanic’s help.
For that, you have RepairSmith.
RepairSmith is a convenient mobile auto maintenance and repair solution. Available 7-days a week, maintenance and fixes can be done right in your driveway.
Contact them for your oil change, and their ASE-certified mechanics will drop by in no time to help!