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2019 Lexus NX 300H - Premium Required?

Do I need to use Premium gas for a 2019 NX300? It is noted everywhere that it does. After reading your article “Is it better to use premium gas or save money.” I am guessing no. Unable to select NX300 as it only shows NX300H. THANKS

There is your answer and you can verify it by looking in your manual .


And that is the correct answer as you noted from everywhere. The folks who designed your car, did so specifically for premium fuel.

Premium is a waste of money for cars that don’t require it. Premium can provide better performance in cars that recommend it but you can run regular if you wish. Yours requires it.


?? If it’s required, then they shouldn’t use regular, right?

You car probably gets some extra power by using an engine with a higher compression ratio. In some cases of engines with high compression ratios the computer can compensate by delaying the spark timing if the fuel grade is lower than premium. You lose a little power is all. However if the owner’s manual says “premium required” then the car’s computer is not able to compensate for lower fuel grades, and you run the risk of engine pinging (pre-detonation) and that can do major damage to the engine’s internal parts.

Correct, but Mustangman said recommended , not required, there is a difference.

The owner’s manual says that you must use 91 or higher octane gasoline, or engine damage may occur. Don’t use regular gasoline.

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Correct. Maybe that didn’t read the way I intended it? Required must use premium, Recommended can still run regular.

I think I misread your post.

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I really don’t understand the purpose of these kinds of posts, and there have been many

OP knows that their car requires premium, it’s spelled out black and white in the owner manual, and all the other information they find says exactly the same thing

you get what you pay for

You buy a car that requires premium . . . that’s what you paid for, and that’s what you got

seems pretty simple to me . . .


The article you are referencing talks about using premium fuel in cars that were designed to operate on regular. The limited information in that article came to the conclusion that using premium in a car designed for regular provided little or no benefit as far as fuel economy or performance.

Your car was designed to run on premium. While it is true that the engine management system will be able to compensate for lower octane in most cases, it does so at the expense of fuel economy and efficiency. In other words, the car will run but not as well as it should.

Why even go down that road? There’s no benefit to it, and a real although small chance that the car may suffer.

From page 398 of the owner’s manual

You must only use unleaded gasoline in your vehicle.
Select premium unleaded gasoline
with an octane rating of 91
(Research Octane Number 96) or
higher required for optimum
engine performance and fuel economy. If the octane rating is less than
91,damage to the engine may occur
and may void the vehicle warranty

The answer to your question is; Yes, premium fuel is required with this vehicle.


Here in San Jose there’s less than a 10% price difference between 87 and 91, so wouldn’t make sense to spend much time worrying about the issue here. Other locations in the country the price hike might be more substantial for premium though.

My grandfather in the catering business used to say if you need eggs, it does not matter how much they cost. I f you need premium fuel it does not matter how much it costs.


One place I worked, I noticed the VP’s secretary seemed to almost always have a pile of about 50 Fed Ex document packages stacked on her desk. Another employee told me the philosophy there was that when something needed to be mailed, time is everything, the CEO doesn’t care how much it costs.

Out of curiosity I got to looking into this issue more. It turned out if you mailed something non-Fed Ex the management thought you were working on something unimportant, and would switch your assignment. That’s the main reason all the packages were going out Fed Ex … lol .


Do you already own this car, or are you considering buying it? If you don’t already own it, I’d keep looking, and buy something else which is designed to run on regular fuel.