RX in NC

We have been running 87 octane from the same BJ's Club pumps for nearly 20 years now. No fuel-quality issues with any of our current or previous vehicles.

I do pour a 20-ounce bottle of Chevron Techron down the hatch every time I do an oil & filter change on all of our vehicles.

Cocal

This is one way to look at things! and this is a bit of tunnel vision.
There are other things to consider and if your ONLY aim to to save money on gas, then absolutely follow this advice, also if you are going to keep your car for 3 yrs or less.
If OTOH you are going to keep you car longer there are other things to consider:
1) What was the octane when the car was tested, one would have to dig to find out and by what I've heard it never is 87 octane, but 91 or higher
2) In the owner's manual it says 87 octane may be used, view this as a warning NOT to go below, at the pump the octane shown is an average in the tank, there is no warning for higher octane.
3) Premium gas contains more additives to keep your fuel system and valves clean and offer better combustion.

There may be more, but this is all I can thing at the moment.

Everyone can do whatever they want, but just as in most car it doesn't say premium recommended neither does it say 87 octane recommended

iolmaster

iTrader: (1)

Sorry man, absolute garbage! That is not how it works.

Cocal

So pray tell us how does it work?

iolmaster

iTrader: (1)

Please see the attached link. It explains why there is no advantage to do what you are suggesting. It comes from the FTC. I know you are Canadian but that stands for Federal Trade Commission. There are many more studies out there also. One from Consumer Reports. They all come to the same conclusion. "Premium" is of no value unless you have a high compression engine. The RX350 does not. There are not more detergents or anything else in Premium vs. Regular. It is all about volatility.

Cocal

It depends how you read the "tests" one can look with tunnel vision as that test did or a panoramic view as to how it effects other things.
If the car was set to run on 87 how come that the computer cannot compensate for a lesser octane? The computer can only compensate so much and the reason why it cannot go lower than 87 is because it was set for 91. Now one can do whatever one wants.
I remember a test that show that if 1 of 2 people ate 2 chickens the test showed that each had 1.

takeshi74

Citation?

That does not mean that there is a benefit to higher octane for a vehicle not designed for it.

Again, citation? Top tier covers additives and one can do as mentioned above and include a bottle of Techron or similar. Octane and addtitives are not the same thing.

riredale

This is getting to sound like an argument about whether a sports car should be red or black. The engine computer will adjust timing. You will therefore lose a bit of peak HP and a bit of fuel economy as the timing is retarded a bit. Nothing else changes. Do what lets you sleep better at night.

iolmaster

iTrader: (1)

Once again, not true. You guys are just not picking up what we are saying. Yes, if you have a knock that is a result of octane that is too low the knock sensor will retard the spark. The bottom line is, if your engine is not designed to run on higher octane fuel (higher compression ratio) putting higher octane fuel in an engine that is not designed to use it gains nothing. You can put high octane fuel into an engine that is designed (lower compression ratio) all the time and it will not, I repeat not, give you more power or better gas mileage. The higher octane fuel is less volatile. I think it best this be my last post concerning this subject.

riredale

I understand; what I was assuming was an engine that recommended premium. Cheers.

Johnny919

Hi everyone, I'm new to the forums. I am in the process of trying to get my mother a car and i'm leaning towards a 3rd generation RX 350. I was wondering what the minimum recommended requirement was as far as fuel is for the 3rd gen rx 350. I've looked online and came across this website...

https://lexus2.custhelp.com/app/answ...xus-vehicle%3F

Can anyone explain to me how a 2012-2015 is recommended 87, while 2007-2011 is rated at 91? Aren't they the same engine?

Thanks for your time!
John

Ranga

I was informed by my dealer that from 2013 onwards the grade has been dropped to regular , but prior to that all the RX models used premium Hope that helps !

Clutchless

It is the same engine in all model years and you can run regular gas in all 2010 - 2015 RX350 vehicles. You just lose a few horsepower. Many of us run 87 octane. It will not hurt anything and you will not notice the difference except in your wallet. Read more of this thread for more information.

Toyota only specified premium so they could say it had more power than the Toyota (5 horsepower).

matthevvmendoza

Which gas do I use for 2015 RX 350? Regular or Premium? Does it matter which one I use?

RX in NC

The 2015 RX runs just fine on regular 87 octane gas. It does not require premium.