That's the way it should be, the average person has no good reason for doing anything aside from that, and for that average person going higher than they need is just burning a hole in their wallet.

On page 599 of the Lexus manual, it states,

You must only use unleaded gasoline in your vehicle.
Select Premium unleaded gasoline with an octane rating of 91(research octane number96) or higher required for optimum engine performance. If 91 octane cannot be obtained , you may use unleaded gasoline with an octane rating as low a 87(reseach octane number 91). Use of unleaded gasoline with an octane rating lower than 91 may result in engine knocking and significantly reduced performance. Persistent knocking can lead to engine damage and should be corrected by refueling with higher octane unleaded gasoline.

My area has only 87, 89, and 93 available. I read in another forum where some say it is ok to "blend" your fuel. So fill the tank with 93 and when it's half empty I fill with up 89. It's a small savings but every penny counts and the NX is running fine. Anyone using regular(87) is asking for engine trouble in the long run.

IMO, IF the cost difference b/w premium vs. regular or mid-grade gives you stress, then maybe you stretch your wallet too much in getting NX.

Remember, buying a car is one thing...MAINTAINING it is another. If you cannot do the second part properly, then you should not buy the car in the first place.

BTW, maintaining your car properly does NOT include using something that the car does not NEED...for example, changing oil every 3000 miles instead of what the Owner's Manual (or computer) says.

Just my 1 cent.

I agree that you need to factor in maintenance when you are trying to see if you can afford your vehicle. Now if people are experiencing car troubles or bad fuel mileage, I'll ask them what kind of fuel they are using.

Thanks a lot for including that. The mixture of 89 and 93 does more good than the instant savings you get at the pump but apparently using higher than required octane burns fuel faster. 2 birds with one stone.

Although there is NO MENTION of a fuel/octane 'requirement' inside the NX's fuel cap area, the owner's manual clearly states that ONLY premium, unleaded gas should be used. It goes on to say that the premium octane 'rating' should be 91 or higher.

On the flip side, some people leasing these might be putting in regular gas and not the level of premium that's required. Just something to keep in mind for anyone who plans on buying one used down the road. If there's any way to tell if this was done, then by all means do the testing required.

This is the key thing. It'll be hard to tell, especially if it's your first time getting in one. Normally you wouldn't know any difference, especially in sound, performance, etc.