Swacer

I'm not going to entertain the fixed budget comment.

MR2's one tank does not represent anything. Without the ability to have a laptop looking at the fuel tables, this doesn't prove anything. You need a computer with tuning software to show you how much timing you are pulling and if that is enough to prevent the car from knocking. Furthermore, you need to be able to see what your downsteam O2 sensor is seeing order to determine if that timing is enough to stop your fuel mixture from going off. Your comment "the computer will adjust" just means you are "hoping" it can without really knowing the range of what it can and can't do.

While I do not discredit MR2, as I appreciate his input on many posts, without actual graphs showing me what the ECU is doing, I respectifully disagree that 87 is the same as 91 without downstream impact.

Butt dynos and mpg numbers show nothing. I personally have never seen a boosted car NOT need premium gas. You are welcome to attempt 87 as many have, but any knock will eventually bend a valve. Then i question to you...how much money did you save on gas before you had to replace the valve train?

LexBob2

The takeaway from this discussion should be, if you're looking at a vehicle where premium is either recommended or required be aware of this before purchase. If it's a deal breaker, or something you'll agonize over or regret shop around for vehicles that recommend regular. There are a lot of choices out there.

rogerh00

Good grief, I'm sorry I brought this up.

If you notice my signature I now own a NX. Thanks for the input.

LexBob2

No offense intended.

Both of our current cars recommend premium. We don't put many miles on either of them, so I use premium in both. If we drove either of them more, I wouldn't hesitate to use mid-grade or even try regular to see how it goes.

I visit both Audi and BMW forums and this topic comes up on them too. I had a 2007 and 2010 ES350 back when premium was recommended for them, and it was a topic of discussion then too. I eventually used regular in both cars.

Wagnerian

One thing I miss about my previous car 2004 Prius is gas mileage. Needless to say my gas money took a huge hit by switching from Prius (regular) to NX (premium with less than half mpg of Prius). Of course I knew all this before purchasing NX and will stick to using premium fuel even if gas price goes back to above $4. As Swacer noted the price difference between regular and premium will always be the same. To me it is not worth risking long term effect by putting cheaper fuel. I am also used to paying for premium fuel price because my SLK requires it and that car has bigger fuel tank capacity than NX.

athiker

From page 8 of the NX brochure: DISCLOSURES 1. Ratings achieved using the required premium unleaded gasoline with an octane rating of 91 or higher. If premium fuel is not used, performance will decrease

http://www.lexus.com/documents/broch...X-Brochure.pdf

I believe I have seen a picture or video of the inside of the gas tank fill lid that has a sticker that uses the word "required". I'm sure someone that actually owns one can verify.

Anyway, I'm only posting to suggest the GasBuddy app, if you have a smart phone, is your friend. The spread between standard unleaded and premium in the U.S. can vary widely from station to station.

For example a BP near me is $2.199 regular and 2.959 premium. QuickTrip (QT) is $2.159 and $2.459. Sam's Club is $2.149 and $2.409. Its seem most brand names like BP and Shell have bigger spreads...maybe for good reason maybe not...IDK. Shell is $2.159 and $2.799.

I've never seemed to have any issues using whatever station I happened upon (I do avoid very old/run down looking stations fearing what crap may have accumulated in the underground tanks however). This would be my first premium fuel car; I don't plan to use anything but premium in my $40k plus car.

Rdcrow

It does say Premium Required inside of the gas cap.

My salesperson said that Lexus tests the engine for fuel economy/performance numbers using premium, and that using lower octane wouldn't result in engine damage but could result in lesser performance.

Joeb427

iTrader: (1)

Guys,Toyota would love to have a 87 recommendation for the NX.
Better selling point but Toyota still recommends Premium.
Why not go with what the Toyota engineers recommend?

Swacer

Been saying this for 2 forum pages....

Toyota honestly couldn't care less about having 87 octane options. Its a luxury car. If you're counting dimes between 87 and 91 grade...you bought the wrong car. They need the 91 for the tuning and for the compression.

Joeb427

iTrader: (1)

If that's the case why is the RX and ES now have a 87 recommendation and the NX 91?I still used Premium in a '12 ES I owned but that's me.I didn't and don't worry about the extra cost of 93 in my area..
Regular fuel is .50 cheaper than Premium in my area and most people would rather have go with 87 .
You have people on this thread looking to use 87.
There's been threads like this with just about every Lexus model that recommends Premium.

Swacer

The first reason would be that you need the additional compression for the turbo. In "most" turbo applications, you use premium.

You are welcome to use premium in a car that doesn't recommend it, but know that you gain nothing in most case because your car lacks the ability to change the timing and adjust the fuel tables to compensate for it.

Joeb427

iTrader: (1)

Yes,premium should be used the NX 200T .It's recommended.Yet some think the can outsmart the engineers and use regular to save a couple of bucks in a $45K luxury vehicle.I can never understand that.

Swacer

Thank god someone else is on the same wavelength as I on this.

Though, I don't think people think they can out think the engineer as much as they just feel its wroth saving a buck and seeing what goes boom, then claiming its Toyota's fault.

Like I said before, count all the dollars you saved using regular over premium, you'll need it when you have to replace the head. lol

nxlee

Seems like Lincoln MKC engineers "beat the system" with regular fuel recommended on both the 2.0L and 2.3L turbos. Both seem to drive pretty well but there is a slight turbo lag in the 2.0.

LexBob2

IIRC Hyundai and Kia recommend regular in their 2.0t engines.

Probably just a case of how different manufacturers decide to go to market with their vehicles.