I just bought this car 2 months ago, in good condition with 48000 miles. I filled it with 87 Octane (from a good gas station) because that's what the manual said. That was a mistake. One time I got stuck on a bridge carrying I90 and I71 in morning rush hour. Bucked and stalled.... couldn't keep it running. Ran really lousy a couple other times. Now I'm filling with 93 Octane everytime the tank goes down a little in order to increase the overall octane in the tank until the overall octane level is much higher.
I traded in a 20 year-old car for this 13 year old car. I am financially challenged and, frankly, the 87 octane that the salesman and the manual told me was a selling point.
I am disappointed.

 

Whatever problem you're having with your car was not caused by using 87 octane fuel.

 

Are you sure your problem is isolated to 87 octane fuel? Since you only bought the vehicle used and only 2 months ago...

 

My Lexus dealer told me that low octane gas was the problem. And I haven't had any problem with higher octane gas (yet).
BTW- The dealer has treated me very well. My warranty was 50/50 and yet they sent a car to drive me to work about 12 miles, another car to drive me home about 20 miles (and offered to drive me to the dealership when the car was ready), towed my car to the dealership about 15 miles and didn't charge me anything. But they didn't fix anything either. And their analysis of the problem doesn't make sense to me.
I had the problem two more times.... In each case the engine was warm, I was traveling up a hill when the problem started at least two of the three times that I had the problem. One time I let it sputter along with my 4-ways on for about 3 miles, never stalling, then the problem went away. Another time, it started sputtering and I drove it with my 4-ways on for about 4 miles, again without stalling, until I parked in front of my house. I called the dealership and brought it to them, leaving about 20 minutes after I got home, with no problem on the drive over. Again, no codes from the computer, the transmission software was up-to-date, the dealer could find no problem and blamed it on 87 octane fuel.
Anybody got any other ideas for the cause of these intermittent bucking, sputtering and, on one occasion, stalling? I would sure appreciate any help you could provide!

 

Just put high test in the car. If that resolves the problem you have your answer. If it doesn't, you have a different issue.

PS-I always ran high test in my ES. Not worth the risk.

 

So, several years back I purchased (by auction) My ES300 2002 model. I filled it with 95 octane and drove it home, some 1500km from Auckland to Alexandra. During that trip the computer was showing me that I was achieving as low as 7.6L/100km. Now that's 30.9493 miles per gallon US. I cannot achieve anything like that when using 91 octane 8.3L/100km (28.3391MPG US) which is a mere 8c a litre cheaper. We are fortunate here not to have any fuel less than 91octane. There is a definite performance difference from the 91 regular unleaded fuel to the premium 95 unleaded and super premium 98 octane. If you drive a Lexus then fuel price to run it will not keep you from having coffee when you fill her up, or having that other condo.
In summary, Higher octane is better for your engine and it feels better when you boot it (floor the gas pedal) as I often do.

 

I'm looking to buy a 4th Gen Lexus ES300/ES330, and I'm trying to find out what vehicles require premium gas and what don't.

According to the owner's manuals available online from Lexus, the 2002 requires premium gas, and the 2003-2005 do not. The 2006 model year once again requires premium gas.

I've googled a lot (and read many old threads here) about premium gas for this generation of ES, but nobody seems to have a definitive answer for this model year. If you can find an old thread specifically talking about the 2006 ES330 model and regular gas, please let me know.

My question is therefore: Does anyone actually own a 2006 ES330, and if so, have you run it with regular (87 octane) gas for years without any issues? Or did you have issues?

Also, anyone know why 2003-2005 would be listed as regular gas in the owner's manuals, while 2006 is suddenly premium gas? Did they retune the engine? I thought all the ES330 had the same powertrain.

Thanks!

 

Hello,

The short answer is no, they do not require Premium (93 octane) fuel.

The long answer is that it is generally suggested to run Premium for more efficiency and a slight increase in the power output, but it is not strictly necessary. You can run 89 octane in this car in exchange of getting a little lower MPG and a tad bit less power; that said, the change is so subtle you probably won't notice the difference unless you would really look for it. As long as you are above 87, you should be fine.

Hope this helps and best of luck!

 

Thanks Arsenii.

Do you know why the 2003-2005 manuals would say "regular" and the 2006 manual say "premium"?

They seem to get the same MPG, despite one recommending regular and the other premium, which doesn't make sense. Even on fueleconomy.gov (official government site), the 2003-2005 models are listed as "regular" and the 2006 is listed as "premium", despite getting the same MPG.

I'm wondering why there was a change in the owner's manuals - was the engine retuned to run better on premium gas (more performance, less MPG, but upgrade in fuel reduces the MPG loss back to the same as before)? If so then me buying a 2006 and running it on regular gas would get less MPG than buying a 2005 and running it on regular gas.

 

As for the confusion in the owners manual - they all call for 91 octane or higher for optimal performance, but in a pinch, you may use 87, which is not recommended, please refer to the snippet below. The only thing that changed in owners manuals is the phrasing (here you can find Owners Manuals for all Lexus models). It was probably more of a marketing thing, since engines from 2002 to 2003 and from 2004 to 2006 were completely identical, but then they realized that everyone started using 87 octane, so they rephrased it back to avoid any sharp corners.. At lest that is my theory. What I know for sure that it is a bad idea to use 87 octane for long duration, it may cause damage.



Also, I am pretty sure that MPG is measured with the recommended fuel, and not the lowest one. Since all of them call for 91, no wonder why MPG numbers didn't change.

Hope this helps and best of luck!

 

True, for 2002 to 2003 there was that unusual change listed above, but if you compare 2003-2005 to 2006 you'll see that the 2003-2005 are all the same and all list regular (87 octane), while 2006 suddenly switches to premium (91 octane).

I'm comfortable buying a 2005 and using regular as the manual specificiation for fuel says "87 octane" - I don't believe that there would be any long term damage from using the fuel listed in the specifications. For 2006, however, the specifications suddenly switch to "91 octane", and I'm worried about buying and running a 2006 on regular fuel. No matter what, I will use regular fuel.

Also the fueleconomy.gov website gives 2003-2005 as regular gas, so I'm thinking they used regular gas in testing the MPG there.

 

This is a direct quote from the 2006 Owner's Manual:

- page ccclii, found here:

https://drivers.lexus.com/t3Portal/d...03U-edited.pdf

I see nothing inherently different than any other 4es, which most of us run on 87. It does run better/deliver better mpg's with 91+ octane, but that's between you and your confessor.

 

I have an 06. You don’t have to use premium but it runs smoother and stronger with it. The gas lasts longer also.

 

Have you been running it with premium or regular? I want to know if there are long term concerns regarding the reliability of the motor for the 2006 with regular gas.

 

Been using straight premium for past 2 years or so. I mainly used regular with the occasional premium fill up the year before that.