2015 Lexus NX - Premium vs regular

Thanks for the info. Great article. I may trade this car in, even though I love it I am worried about the long term effects of running regular.

The financial loss you will incur trading it in and getting something different would probably pay for 20 years of premium upcharges.

1 Like

The price you get will probably be pretty far from the price you paid. How much premium gas would that money cover?

You are probably right. Thanks for the reply

If the price of the correct fuel has you this concerned that you would consider losing money on this vehicle you have bigger problems. Start by looking at other things you might change in your home budget.

Are you kidding? Six bucks for a cup of coffee?

Car salesmen are not usually known for being the most honest people, and many of them don’t even know that much about the models that they are selling. That is why it behooves car buyers to fully research the car models that they are considering buying.

Even if you don’t delve into every aspect of a car, it is important to investigate the factors that are important to you. For example, I don’t care about towing capacity, so I wouldn’t research that factor, but because I am interested in not having to pay for premium gas, I always check-into that factor.

Expecting a car salesman to volunteer the information that this model requires premium fuel is simply not realistic.

Guess I’m lucky, mines only $5.25

We have a spread sheet we take with us that has items that we must have , things that we would like to have and things that will cause the vehicle to be marked off the list. Premium fuel being one of those.


I assure you that I can afford the extra $6.00 a fill up that this vehicle is going to require. I simply asked the question to see what long term affect using regular in this car would entail. Also you may have seen the article that one person put up regarding the use of premium fuel unnecessarily. I have several classic cars that I already use premium fuel in. I would just rather not have to use it in my every day driver. That being said I guess I will continue to put premium in it. Thank you for your reply.

Technology marches on. The 2 Liter two liter engine in Europe and worldwide and development of that engine class has been insane, The NX got the engine in 2015 but it was used in another vehicle first. Just because others have surpassed it now doesn’t mean it was not state of the art when designed. Companies are designing high output engines that severely cut back on power by timing because they now know Americans are going to put 87 octane in no matter what the maker recommends. The husband may want a high performance car but the wife is no going to spend more of her money tha she has to to fill the tank.

Yes, that is a sexist generalization, but like many generalizations, generally true.


My wife spends an average of $7 a day for coffee and a pastry on the way to work every morning.

Umm, I’m confused.

It’s my professional opinion that under normal everyday driving conditions you are unlikely to do major damage to your engine by using regular. It will not perform as designed and will probably give you lower fuel economy. But why take a chance on the engine and why tolerate lower performance for $6.

1 Like

There will very likely be no long term effect. The NX200t has been out for 4 years, the IS200t and the GS200t for 3 years, owners aren’t compliant with fuel requirements and there have been no engine problems. As I mentioned before the PCM is capable of recognizing pre-ignition problems and setting a fault.

The most common problem that I encounter with the NX is HVAC servo motor failures.

I would echo the confusion of other posters. You purchased a luxury SUV, I’m guessing for somewhere around $30k and are stressing about an extra $6 per tank of gas. I purchased a 2017 Audi A4 that also requires premium. It’s a great car with a great engine, but to get the performance, it uses higher compression ratios and needs premium fuel. Would I prefer to save $0.40/gallon? Sure, but I simply view this as a cost of getting to drive a great car. if I wanted to save money on gas then I could have purchased a Mazda 6 or a Toyota Prius. :face_vomiting:

You may be able to get by with lower octane gas, especially if you drive conservatively, but as others have pointed out, you risk damage to your engine that would far exceed the cost of the premium fuel, will compromise the performance of the engine and may get worse fuel economy.

I get the impression that this is not really a financial question, rather it’s the fact that you’re paying a little extra for fuel that’s eating at you. My advice to you is simply accept the fact, not worry about it and enjoy a great car. If you can’t do that, then you can look at trading the car in, recognizing that the actual financial cost of that will likely be more, but it wouldn’t eat at you every time you fill up the tank.

1 Like

Spark knock/detonation varies with intake air temperature, so you might be OK with mid-grade in winter.

If it matters … I think it is the case. correct me if I’m wrong, but if there’s potential damage by using a lower octane gasoline than specified, the damage would be to the engine, not to the turbo unit. The turbo makes pre-ignition (damage causing pinging) more likely, but that occurs in the engine’s combustion chamber.

It seems to me that when insurance, depreciation, license fees, maintenance and upkeep are considered, gasoline is a small part of the operating costs of a car.
I don’t agonize over gasoline mileage. I served my time in a Ford Maverick and Ford Tempo and a Rambler. I want a car that meets my needs and is comfortable. If I had a Lexus, the last thing I would worry about is whether or not premium is required. If it is, put in premium gas and enjoy the ride.


I agree with you completely! But I’ve read and heard many, many people with luxury or near luxury brands ask the same question as the OP. They do NOT want to pay for premium fuel even though they just threw down an extra pile of cash on their Lexus, BMW or Audi that requires premium fuel. I don’t understand how you can be extravagant up front and cheap down the line.

Tires are a good example of that, too. Car comes with $1200 set of premium tires. Owner balks and buys $75 each BlackDumpling Ride Prince cheapo tires and then complains the car rides like a dump truck and howls like a dying moose on the highway afterwards.


I also don’t understand how someone can fail to do his/her due diligence regarding a vehicle prior to purchase. Before buying a vehicle, simply reading materials that are available online, and/or looking at the gas cap, and/or glancing at the Owner’s Manual, and/or (perhaps) looking at the gas gauge itself would have yielded the information that this is a premium-fuel vehicle.