tmuti13

what is your opinion on running 87 octane fuel? I've had my 01 rx for 5 months and have been running 93 octane. the vehicle has 77K miles, (i bought is with 64K miles) and I don't know what fuel the previous owner was running. I spoke to a friend who has a ls400 and he said that he runs 87 octane and has not had any problems.

Horta

The RX only needs 87. Anything over that is just a waste of money. I have been running 87 on my RX for the last 60k will NO ill effects. Every blue moon I use 93 with techtron just to clean things out. My RX runs perfectly smooth and strong.

Now on my LS I Only use 93 because thats what the car requires.

At the same time some people just "Feel" better putting in 93 no matter what the cars Owners manual says. Thats fine people are more than welcome to do what they please. 93 will not hurt at the same time it will not make you car perform any better.

HarrierAWD

I've been running only 87 octane in my 2002 RX300 the last 36K miles. Not a problem. The manual does say that higher octane can give better performance. Tried it and didn't notice anything, so I stick with 87.

Higher octane fuel does not contain more cleaning agent than regular gas. Frankly I doubt Techron or STP actually do jack to the injectors. Buy gas from any major brand and you should do fine.

Get an oil company credit card with 3% rebate for additional savings.

Horta

Yeah I live in South Florida. We regularly go to Orlando to visit family and gas is 20 cents cheeper up there. Every once in a while I put the 93 only because its the same price as our 87 back home. Also I know that tank will get burned thru quickly sence we use alomst an entire tank to make the trip.

Does the techtron clean the injectors, I really have no clue. But my cars does run great so I guess I'm treating it ok.

I do remember an article some years ago that did a test of a current year Corvette and the current year Cadilac. The test was how do the engine compare when useing 87 vrs 93. Both cars required 93. The Corvette lost a mesuarable amount of Horse power ( I dont wish to quote numbers cause I just dont remember, but it was surprising.) Then the cadilac did not loose any HP because it had some speacial design that alowed it to run on lower octain if needed.

LeXuSrAcIn

I heard that using higher octane ratings yields better MPG. True?

flipside909

This was discussed in the ES forums regarding octane for the 1MZ/3MZ mainly.

https://www.clublexus.com/forums/sho...threadid=92093

flipside909

Not entirely true.

NeverSatisfied

I use the middle grade (89).

gsenthil

87 for 55k miles. I do try to fill Chevron gas as much as possible and willing to pay a few cents extra for it. i remember reading car & Driver reports on octane where they concluded it is a waste and maybe detrimental if you use higher octane than specified. I dont know why Lexus says 87 "OR HIGHER" in the manual making people believe higher octane will yield higher performance/mpg

flipside909

Because the 1MZ-FE and 3MZ-FE are high compression engines 10.5:1 and 10.8:1 respectively, they benefit from higher octane fuels. Where as a regular motor with a cr of 8 or 9:1 will not utilize the benefit of higher octane fuel. Of course with the dual banks of knock sensors, the computer retards/advances timing to pinging/detonation conditions anyways.