BLUEGXLVCR

I'm voting only a coincidence. Makes no sense at all. If you told be he put diesel in, I'd buy that.

ALAN553

No way it was the gas

redrocks

So how did he get it started? Pumped all the gas out of his tank? And then filled it with premium?

wokraku

89 all the way with occasional 93.....that is the recommendation

ALAN553

Trying to understand the purpose to the occasional use of higher octane ? Is there a benefit to the use of it other than increased performance while using that tank of gas? Other than the higher octane, is there something else in there that I am missing?

cssnms

Outside of a slight improvement in performance there is NO other benefit to using Premium in the GX. (re-read my post #26)

The GX owner's manual says the following, Lexus requires that you use an octane rating of 87 and above in your GX. For improved performance they "recommend" premium. To that end a higher octane gas will do nothing to keep your engine cleaner. Using only quality gas that adds quality detergents e.g. Chevron w/Techron is more important IMO then the octane count. Chevron not only adds their proprietary detergent, Techron to their gas, but they add it at levels above the minimum required by the EPA, whereas most gasoline/oil companies add only the minium. Add a bottle of Techron every 4 to 6 months as a preventative measure to keep injectors clean.

cssnms

The octane requirement per the owner's manual is 87 and above, while premium is recommended for improved performance. 89 is a compromise and a waste of $ IMO as the performance gain over 87 is negligible.

cssnms

No. It has nothing to do with the gas. Modern combustion engines that "require" premium can run on 87 octane. It's not the best thing for the engine long term, and performance will be greatly compromised, but it will run.

ARehman

I don't own a GX but on my IS I use premium. I did have to put regular in it once when I was out in BFE and the tank was pretty much totally empty, oddly enough it started but didn't idle normally. Have never used anything lower than 91 since that time. The other reason why I would only use 91 is that in my area anything lower usually is a combination of ethanol and gasoline.

cssnms

There's a difference,,, for a variety of reasons, the IS "requires" premium while the GX is "required to use 87 octane and above. I only put premium in my IS.

Ethanol is in ALL grades of gas in my area at 98% of the stations - it kills mpg's. Non ethanol gas will become increasingly more difficult to find and if our beloved bureaucrats have anything to do with it, it will eventually fade away all together.

ChrisK

iTrader: (1)

Cut and paste straight from 06 GX user manual:

"Select premium unleaded gasoline with an Octane Rating
of 91 (Research Octane Number 96) or higher for optimum
engine performance. However, if such premium type
cannot be obtained, you may temporarily use unleaded
gasoline with an Octane Rating as low as 87 (Research
Octane Number 91)."

Cut and paste straight from 07 GX user manual (same as 08 and 09):

"Fuel types
Use premium unleaded gasoline. (91 Octane Rating [Research Octane Number
96] or higher)"

cssnms

It would appear we have a quandry...

Cut and past straight from my my 2005 GX Owner's manual....

"Select Octane Rating 87 (Research Octane Rating 91) or higher. For improved vehicle performance, the use of premium gasoline with an Octane Rating of 91 (Research Octane Number 96) or higher is recommended."

There are no engine differences between your GX w/the VVTI engine and my GX w/the VVTI engine. IT is perplexing why Toyota says it's okay to use 87 octane in my GX, but not yours? In addition, Toyota does not recommmend premium gas in the 4 runner V8 which has the exact same engine.

The pump gas octane rating of 87 is the mean of RON and MON, which equates to avg RON rating of 91 octane.

In 5 yrs no problems and no knocking. I will keep using Regular.

cssnms

FWIW, the GX did not exist in 96 97, 98 or 99. I assume you mean 2006? But that begs the question; why you wpuld have a 2006 Owner's manual for a 2005 GX?

ChrisK

iTrader: (1)

Yes, I meant 06, 07, 08, 09.
I looked all of them up because they are available from Lexus. It was pointed out how user manual says 87. That is not necessarily true without providing the specific year.

cssnms

Was the 2005 Owner's manual not available?