On this site, we do in-depth study into particular queries regarding numerous autos. Today, we’ll examine the Kia Optima/K5 to determine the type of gas it requires. In order to determine the optimum gas for the Kia Optima / K5 from 2009 to 2021, as well as a thorough examination of the engine, mileage, and tank capacity of various Kia Optima / K5 models by year, we combed through owner’s manuals for these vehicles. Here is a quick summary:
A high-quality unleaded regular gasoline with an octane rating of 87 is intended for use in all Kia Optima and K5 vehicles. It is not advised to use premium fuel with an octane of 91 or higher because the Optima/K5 will not profit from doing so.
However, this does not provide all of the specifications. In this post, we’ll get into the specifics of the Kia Optima and teach you about the many types of gas for this car, including which ones are best or worse for the performance and durability of the engine. We’ll also go over tank size and how much it costs to fill a tank in different states.
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In This Article...
87 normal gas is it?
Any type of gasoline with an octane level of 91 or higher is commonly referred to as premium gasoline, with 91 octane and 93 octane being the most popular brands sold at gas stations in the United States (93 octane gasoline may be called “ultra or “super-premium in some cases). Most gas stations designate gasoline with an octane level of 89 as “midgrade,” whereas gasoline with an octane level of 87 is known as “regular.”
What kind of fuel is 87 octane?
Measures of gasoline stability are called octane ratings. These rankings are based on the pressure at which a gasoline will spontaneously ignite in an engine under test. Actually, the octane number is the simple average of two distinct octane rating systems. The main differences between research octane rating (RON) and motor octane rating (MOR) are the particulars of the operating conditions. The fuel is more stable the higher the octane number. According to octane rating, retail gas stations in the United States offer three different classes of gasoline:
- Regular (the lowest octane fuelgenerally 87)
- Midgrade (the middle range octane fuelgenerally 8990)
- Premium (the highest octane fuelgenerally 9194)
The octane rating is referenced in all of the names for these kinds of gasoline that certain corporations use, including unleaded, super, and super premium.
A petrol pump displaying several fuel grades and octane ratings on the yellow labels.
The minimum octane rating is shown by the huge number on the yellow octane label on petrol pumps. The octane testing method is identified on the label as (R+M)/2 Method, where R stands for Research Octane Number and M for Motor Octane Number.
The 2,2,4-Trimethylpentane molecule, which is extremely resistant to auto-ignition, is one of the 18 isomers of regular octane (C8H18), which is where the name of the fuel comes from. For testing purposes, this iso-octane has been given the reference value of 100. The 0 octane reference fuel is the exceedingly unstable normal heptane (C7H16) molecule.
Is a Kia Optima fuel-efficient?
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With a combined gas mileage rating of 29 mpg, the 2019 KIA Optima sedan offers a respectable level of fuel efficiency. The mid-sized vehicle delivers 25 mpg on city streets while achieving 35 mpg on the highway.
Are Kia Optimas reliable vehicles?
The 2020 Optima is a reliable used car, yes. This sedan offers a comfortable ride, a stylish interior, a sizable trunk, and a feature-rich and user-friendly infotainment system. Additionally, it offers a ton of safety features and one of the best safety ratings among midsize cars.
Can I put unleaded 88 in my car?
- E15, which is frequently marketed as Unleaded 88, is a mixture of 15% ethanol and 85% gasoline. It has 5% more ethanol in it than E10, the most widely used fuel in the US. While E10 has an octane rating of 87, E15 has a higher octane typical of 88. To emphasize its high octane value, retailers are selling E15 as Unleaded 88.
- Up until recently, gasoline ethanol mixes could include no more than 10% ethanol, or E10. 97 percent of the gasoline sold in the US is E10. Unleaded 88 uses the same kind of ethanol as is blended into E10, but the amount of ethanol in a gallon of gasoline is increased from 10% to 15%.
- The U.S. Environmental Protection Agency (EPA) has given unleaded 88 permission to be used in all automobiles, trucks, and SUVs manufactured in 2001 and later. According to the EPA, more than 90% of gasoline sales is used in vehicles with a model year after 2001.
- The ethanol sector petitioned the EPA in 2009 to lift the current cap of 10% and allow a blend of up to 15% ethanol in gasoline. By replacing conventional gasoline with low-carbon ethanol, increasing the blend from E10 to E15 will hasten the use of renewable fuel, boost energy security, generate jobs in the United States, lower transportation costs, and benefit the environment.
- In the history of the EPA fuel waiver procedure, Unleaded 88 has undergone more testing than any other gasoline additive. The U.S. Department of Energy tested Unleaded 88 in a variety of vehicles for 6 million miles and found no issues.
- Unleaded 88 is permitted for use by automakers. More than 93 percent of model year 2019 vehicles have express manufacturer approval for the use of Unleaded 88, according to an RFA analysis. Ford recommends Unleaded 88 for its 2013 and newer vehicles, and General Motors recommends Unleaded 88 starting with its 2012 model year vehicles. Volkswagen, Audi, Toyota, Land Rover, Porsche, Jaguar, Honda, Subaru, and some Mercedes-Benz and Lexus cars are also permitted to run on unleaded 88.
- It’s also crucial to remember that certain fuels and gasoline additives, like fuel stabilizers or octane boosters, aren’t always included in vehicle owner’s manuals. The use of fuels and gasoline additives not specifically listed does not always make a vehicle’s warranty void. In fact, if the use of a different fuel did not cause the issue for which the warranty claim was submitted, vehicle manufacturers may not reject a warranty claim based on that reason.
- Unleaded 88 and normal gasoline have very imperceptible mileage differences in a real-world setting. In a controlled environment, ethanol’s effect on fuel economy would be equal to the loss of energy density, according to studies by Oak Ridge National Laboratory and the National Renewable Energy Laboratory. When compared to ordinary gasoline, this results in an Unleaded 88 loss of less than 2%. This would translate to a loss of about 29.4 mpg for a car getting 30 mpg, or roughly the loss of miles per gallon when a car’s tires are not properly inflated.
- Ethanol continues to dramatically cut greenhouse gas emissions, according to a U.S. Department of Agriculture report (GHG). According to the report, using ethanol as a transportation fuel reduces greenhouse gas emissions by 43%, and if current trends continue, these reductions will reach 47% by 2022.
- At the pump, unleaded 88 is clearly distinguished. For usage in passenger cars manufactured after 2001 and flex-fuel vehicles, look for the government-mandated orange and black label mentioning E15 (as seen on the right).
- Nearly all of the gasoline infrastructure that is currently in place can use unleaded 88 without risk of damage. According to studies by Underwriters Laboratories, gasoline blends having 15% ethanol should be used at American gas pumps.
- Unleaded 88 was not permitted to be used in automobiles manufactured before 2000 by the EPA. This was partly because older vehicles have a variety of factorssuch as mileage, state of repair, and types of usethat would render test results ambiguous.
- Because many non-automotive engines lack sophisticated computer controls to account for fuel variances, the EPA did not approve usage for Unleaded 88 outside of the automotive industry. These engines come in several sorts and sizes and are used in different applications.
Premium Gas Offers Better Performance
This myth is partially true and partially false. The majority of automobiles operate at the same level of performance whether you use standard or premium petrol. You’ll only notice a noticeable difference between the two with particular car models and engine types.
You Need to Use Premium Gas if It’s in Your Car Manual
This myth also rests on circumstantial evidence. Many automakers, like GMC, Ram trucks, and the works, will indicate in the owner’s manual for some of their cars whether they advise or demand the use of premium gasoline. What counts is how these two terms differ from one another.
There are certain advantages to using premium gas when the manual advises against it, but using regular gas won’t hurt your car. It won’t void your warranty in this situation either. Premium gas could potentially improve the performance of these vehicles.
But if the owner’s handbook specifies premium fuel, it signifies the engine does really require higher octane levels to operate properly. Using conventional fuel in these vehicles could potentially harm the engine, and your warranty won’t cover these damages.
Make sure you carefully study your owner’s manual before buying a new or used automobile to make the best decision. Save yourself the money if it’s not necessary.
Premium Gas Lasts Longer
So, is premium fuel more durable? This appears to be a lure of using the ostensibly higher grade fuel for many people. Who among us wouldn’t like to visit the petrol station less frequently?
Regrettably, premium gasoline contains nothing that would extend its shelf life relative to other fuels purchased at the pump. Since the higher octane levels are what set them apart, the only true advantage is a decreased risk of engine knocking, which poses no danger with most contemporary fuel systems.
Premium Gas Cleans Your Engine
This myth is untrue, much like the idea of living longer. The majority of engines are effective in removing residue. You’re in better shape keeping up with routine maintenance checks if you’re worried about the cleanliness of your vehicle’s components.
Regular gas is unleaded, right?
Unleaded fuel is indeed the same as ordinary fuel. Since the 1970s, leaded gasoline has been illegal and is no longer sold at the pump.
Because unleaded gasoline is more environmentally friendly and has a higher octane rating than regular gasoline, it is now the preferred option for drivers. It costs extra money as well.
However, a lot of drivers discover that putting standard gas in a car that needs premium can reduce performance or harm the engine. For these reasons, it’s crucial to only use gasoline that has been approved for your car.
How can you tell if gas is leaded-free?
Fuel with an octane rating of roughly 87 is unleaded gasoline. The DOE notes that fuel has three different octane ratings: 87 for unleaded fuel. 88-90 for mid-grade fuel.
The 2018 Kia Optima isn’t as fuel efficient as some of its competitors, but 25-mpg combined or better isn’t bad.
One of the first automakers to use only 4-cylinder engines in their mid-size vehicle portfolio was Kia. Others are doing the same.
The 2.4-liter inline-4 available in base models and the new S trim, with an EPA rating of 24 mpg city, 34 mpg highway, and 28 mpg combined, will be the most popular engine. That receives a 7 out of 10 on our scale for fuel efficiency. (Learn more about our rating system for automobiles.)
While some rivals will achieve higher fuel efficiency than the Kia Optima, Kia is still competitive with those models.
Without choosing the hybrid models, which we examine separately, the more economical 1.6-liter cars will receive the top ratings of the lineup at 28/37/31 mpg.
The Kia Optima’s top-trim models come with a 2.0-liter turbo-4 engine that, according to the EPA, achieves 22/31/25 mpg. We believe that using a light foot could help you get greater results in the actual world.
All Optima models are approved for normal unleaded, which might result in cost savings at the pump.
Is leaded fuel premium?
When asked whether standard unleaded petrol or premium gas is better, the majority of automobile owners receive a wide range of responses. Some have rejected this back-and-forth discussion among industry participants as being useless, like watering a tree in the rain. For them, there is no distinction between regular and premium gas.
Then there are those who assert that premium gas is better for their cars since it has so many advantages over regular gas, including improved engine performance and fuel efficiency. Some contend that “difference is a marketing ploy to increase your fuel costs.
It can be challenging to choose which fuel to utilize with this much information. Continue reading to learn more about normal unleaded and premium petrol options.
Unleaded gas actually contains no lead at all. Despite being a widely used phrase, this was not always the case. In the 1920s, tetraethyl lead was added to gasoline, largely to lessen engine knock and boost fuel economy and octane levels. Gas was all there was back then; there were no additions. However, it was quickly discovered that lead was a neurotoxic and contaminant that harmed emission control technology.
After leaded fuel was outlawed in the USA in 1996, unleaded fuel was introduced. Most owners today have modified older vehicles that used leaded petrol.
The most popular type of gas is regular unleaded gas (RUG), which is used all around the world. It is a crude oil byproduct with an octane rating of 87 and is quite combustible.
Because it has an octane rating of 90 or greater, premium gas is frequently referred to as “high octane.” It is a by-product of crude oil that is unleaded, has detergent additives, and is less polluting.
The ability of fuel to survive incorrect combustion in an engine is measured by its octane rating. An air and fuel mixture is compressed in a typical internal combustion engine before being ignited to produce a controlled explosion. Pre-ignition, often known as “knocking,” occurs when the mixture burns before it should. This can harm some engine components and decrease performance.
Premium gas has a higher octane rating than RUG because it can survive pre-ignition better than RUG.
Prices as they are really paid vary by location. Premium gas, on the other hand, might cost anywhere between 20 and 50 cents more per gallon. For someone who uses their automobile regularly, this may amount to hundreds of dollars per year.
Regular gas burns more quickly and is appropriate for vehicles with low compression ratios or low performance needs. In high compression engines seen in high performance vehicles, premium gas is suggested since it burns more slowly.
The manufacturer’s recommended fuel is frequently listed in car manuals, although unless specifically stated, it does not imply exclusive use.
Drive the vehicle using both fuel types. Just be sure to use both before recharging with the first.
There are times when it is wise to use premium fuel, such as while traveling over rugged terrain or hauling heavy loads. Learn more about these situations, as well as fuel-saving accessories and recommendations.
Premium gasoline can be advantageous, but it differs significantly from RUG in terms of octane rating, cost, and engine appropriateness.