Top 9 Motor Oil Brands to Avoid

If you’re in the market for some new engine oil, make sure to avoid these 9 brands. Here are the ones to keep out of your shopping cart.
Written by Natalie Todoroff
Reviewed by Melanie Reiff
Of all the motor oil brands on the market, Liberty Motor Oil, Bullseye, and Q10-40 rank among the worst. They combine thin, low-viscosity oil with not enough additives to craft a cocktail that’s sure to do much more harm than good to your engine. 
Motor oil plays a crucial role in your car’s engine. Your engine is chock-full of moving parts that need to be lubricated to work. Without this lubrication, you run the risk of doing some serious engine damage. 
Not all engine oils are created equal. In fact, using a shoddy engine oil brand can actually do major harm to your vehicle and potentially send you to your mechanic’s shop with a hefty bill. 
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Why does the motor oil brand matter?

It may seem a little snobbish to only purchase specific name-brand motor oils, but being choosy about what you put into your engine when conducting an oil and filter change can actually help it run smoother, for longer. 
Although motor oil is intended to help your engine, purchasing it from a low-quality brand can actually do you more harm than good. Continually using a bad motor oil brand can do long-term and expensive damage to your engine. 
Each motor oil brand adds their own special, secret-recipe blend of additives and chemicals to their oil. When done right, these additives can work wonders in improving engine function. But done wrong? It can wreak complete havoc on your engine health. 

What to look for in a bad motor oil 

From the outside, all motor oils may look the same. But, that isn’t at all the case. Luckily, you don’t have to be an automotive engineer to know how to weed out the good motor oils from the bad. Here’s what you should keep an eye out for: 

Viscosity Index 

Viscosity is how thick an oil is. Generally speaking, engine oils become thicker in colder temperatures and thinner in warmer ones. 
You’ll want an oil that hits that Goldilocks zone of being not too thick to gunk up your engine in cold winter months, and not too thin to stop performing in your engine’s ultra-hot operating temperature of 212°F. 
That’s where the viscosity index comes in. It measures how well the motor oil is able to adapt its viscosity according to the weather. The viscosity index is different for each oil brand, and whether or not you need a single or multi-viscosity oil depends on your specific engine. 
This is where your owner’s manual comes in handy. It will tell you the right kind of oil viscosity your engine needs, whether that’s 0W-40, 5W-30, 10W-20, etc. 

Oil type

There are five primary types of oil, and each one is suited for different kinds of engines:
  • Conventional oil: Oil made from petroleum. Conventional motor oil burns more easily than the other types and thus should not be used in older vehicles or vehicles with a lot of miles on them. 
  • Synthetic oil: A man-made lubricant composed of various chemical compounds. Synthetic motor oils are best on newer vehicles with less than 100,000 miles on them and generally last longer than conventional oil.
  • Mineral-based oil: Oil that is derived from crude petroleum and heavily refined. Mineral-based oil is the cheapest of the five but doesn’t do much to protect your engine. 
  • Synthetic blend oil: Oil that is a mix of synthetic and mineral oil. Great option for those in cold environments, but less long-lasting than a purely synthetic motor oil. 
  • High-mileage oil: Oil that is specifically designed for engines with over 75,000 miles on them. High-mileage oils are usually more expensive, but are long-lasting and protect even the most fragile engine parts. 
As you can see, different types of oil are better for different types of engines. This is another instance in which your owners manual can help point you in the right direction; it will usually specify which kind of oil is best for your engine. 
MORE: Synthetic or conventional oil: which is better?

API symbols

API stands for the American Petroleum Institute. They are an entity that regulates and quality-checks different motor oil brands. There are a slew of different API symbols, but you’ll want something that has a rating of SP or higher. 


Additives are extra chemicals that motor oil companies add to their oil to help prevent buildup. Additives can also manipulate the oil’s viscosity in various temperature conditions. 
Higher-quality motor oil brands use higher-quality additives in their oils, while the ones in low-quality oils are much more volatile and can actually create rust buildup. 
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Engine oil brands to avoid

Whether you opt to do your oil change yourself or take it in to a mechanic, take precautions and avoid using these bad motor oil brands in your engine. 

Liberty Motor Oil  

Insufficient additives and a poor viscosity index made Liberty Motor Oil a non-starter. Under high temperature conditions, Liberty Motor Oil will become too thin and do a poor job at keeping your engine lubricated. 
Its high volatility rate also means that this oil will evaporate quickly, which can also harm your engine. 

Xpress Lube Pro Motor Oil

The fact that none of the motor oils in Xpress Lube Pro are approved by the API is a huge red flag. To add insult to injury, they not only use low-quality oil chock-full of impurities, but the additives they use can also glob up in your engine. 

Questron Motor Oil 

Don’t be fooled by Questron Motor Oil’s “premium quality” label. Their viscosity ratings aren’t backed by either the API or SAE (Society of Automotive Engineers), and their oils tend to do a poor job of lubricating the engine. 
They have a generally low viscosity level, which creates all kinds of loud engine noise.  

Bullseye Motor Oil 

Although Bullseye Motor Oil comes in sleek, stylish packing, that doesn’t speak to the quality of the product. 
Regardless of what it says on the bottle, their oils are too thin to protect and lubricate your engine. There are very few additives in their formula as well, which creates all kinds of harmful sludge build-up. 

Q10-40 Motor Oil

It’s a similar story with Q10-40 motor oil. This one also does not have enough additives or detergents to actually help protect your engine. 
Its poor viscosity index also causes it to become dirty after being exposed to high temperatures. It’s so bad that using Q10-40 Motor Oil has actually been proven to increase friction and engine corrosion. 

Quaker State Q Motor Oil 

Quaker State Q Motor Oil packs a one-two punch of producing low-quality motor oil at a high performance price. It has a high volatility rate and does not have enough essential additives to keep the engine running smoothly. 

Petrola Motor Oil 

Get this: Petrola Motor Oil products are formulated to work in vehicles manufactured before 1930. If that wasn’t enough to dissuade you, their labeling does not comply with the Federal Trade Commission’s
Fair Packaging and Labeling Act
But let’s get into what’s inside the bottle: not enough additives and a high volatility make this oil a no-go for any driver. 
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Xcel Motor Oil 

Rounding out our list of worst motor oil brands is Xcel Motor Oil. And, unlike the Microsoft spreadsheet program, this one is anything but helpful and efficient. 
In fact, it’s so terrible that there’s actually been a
class action lawsuit filed against them
and their oil has been dubbed “cancer for cars.”  
Xcel combines extremely poor-quality oil and insufficient additives. Many drivers were attracted to its cheap price point, but found themselves paying even more to fix their engines after using this oil. 
MORE: How much should an oil change cost?

What happens if you use bad motor oil?

We mentioned earlier that using poor quality motor oil can be bad for your engine, but just how bad can things get? For starters, you’ll begin to notice oil leaks underneath your vehicle. 
For instance, using synthetic oil in cars that can’t handle it can damage your engine’s gaskets and seals, which creates a puddle of oil beneath your car. 
Motor oil doesn’t just lubricate your engine, though that’s arguably its most important job. It also helps absorb excess heat, so using bad motor oil can cause overheating—and you don't want to deal with any
engine fires
With the wrong oil in its engine, your car will also have to work harder to overcome the increased friction between your engine’s parts, which can decrease your fuel economy. 
Most importantly, using bad motor oil can cause engine failure. If the fragile metal parts of your engine are rubbing up against each other, they will wear out and break. And a new engine won’t come cheaply: on average, it costs between $3,000 and $5,000. You’re better off spending a little more on a high-quality engine oil to begin with! 
MORE: Does insurance cover engine failures?

How to find cheap car insurance 

A cheap motor oil may not do what you need it to for your vehicle, but that doesn’t mean you shouldn’t try to find the best bang for your buck. 
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There is no one absolute best motor oil. However brands like Mobil 1, Castrol GTX, Royal Purple, Pennzoil, Amsoil, and Valvoline make reliable high quality motor oils.
In a pinch, it’s completely fine to mix brands of oil as long as they have the same viscosity. However, you should avoid mixing brands if you can: each formula has a different level of additives, and throwing off the balance in each formula can cause engine damage.
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