07LexusGuy

I just use whatever the manufacturer suggests. Lexus says to use 87, then it should be able to use 87 without any problems.

I dont think using 87 octane will damage your sensors. If your use of 87 octane causes your RX's fuel system to fail, then you might have a lawsuit on your hands since the manufacturer recommended it.

I use 87 in my RX but I only buy from Top Tier gasoline brands and avoid more questionable places.

It costs me less to fill up my RX as compared to my ES and GS (both use premium)

BertL

Sort of depends upon who you want to listen to. The debate goes on and on, and we spin and spin on the same subject here every few months. Personally, if I owned a 2013 RX350, I'd follow Lexus direction and use regular and save a few bucks. Page 142 of the 2013 RX350 owners manual says unleaded regular is what should be used. They are the engineers, documented it, and support that decision for their warranty (and extended warranty if you had one.) You could of course run premium if you decided to for any number of reasons as you've read -- Lexus would still support that decision, I'm sure. ...but again, I wouldn't personally elect to give another 20 cents per gallon in my case here in SoCal to the oil companies when I didn't have to, and could still be following the manufacturers recommendation for my $40K+ ride.

Me, well, I have a 2013 RX450h, and it is Lexus official position to run premium in it. That's what I personally elect to do, knowing many folks here on the forum save money, run regular in their hybrids, and seem to be happy with their decision.

Good luck with yours!

Poisson

Interesting (and much repeated) discussion. Can somebody clarify for me what octane ratings are in the US? I saw mention of 87 above - that seems extremely low. here in Oz, regular ULP is 91, premium is 95 and super premium is 98 (and a very big price hike). I ran my RX350 (2006) on 91 regular, but Lexus recommend 95 premium for the 450h so that's what I go with.

CanadianRX

I believe in 2012 Lexus lowered the octane and power ratings for the RX 350. Since I lost 5 hp and something like 9 ft lbs of torque I'm not waisting my money on premium. Hybrids are still recommended for premium though.

BertL

Paul, here in Southern California that has some of the most stringent air quality and therefore fuel type regulations, 87 is typical for regular unleaded and 91 for premium unleaded gasoline. These days, most pumps only provide the two choices of unleaded gasoline, and here both tend to include 10% ethanol. A third choice on some pumps is diesel. "Leaded" gasoline is fairly difficult to find. State air quality laws take precedence, so other parts of the USA and I believe Canada may have varying octane ratings (and perhaps still even a third higher octane rating that I seem to remember having read about somewhere). In any case, the 2013 USA Lexus RX manual only makes reference to 87 for the RX350 and 91 for the RX450h.

RX330inFL

Keep in mind that like many things here in the US, we use a different rating system when it comes to gasoline octane. The pumps may read 87/89/93 octane, however, that is using the AKI system. The same rating system is also used in Canada. The RON values are 91/93/98 if memory serves me correct..

So, your Super Premium 98 RON octane would be equivalent to our 93 octane here in the US and Canada. Your 95 RON octane would approximate our 91 octane. Sounds like you are getting the same stuff as we use here when it comes to octane.

In some locations here in the US you will find 85 octane, high elevations, and others selling 91 octane instead of 93 octane. Depends on the station and locations.

http://en.wikipedia.org/wiki/Octane_rating

RX330inFL

Welcome to Club Lexus, aznboi88.

In 2004 and 2005 Lexus stated the RX330 needed 87 octane in its Owner's Manual and sales literature. From 2006-2011 they stated the RX330 and RX350 needed 91 octane. The hybrids, I believe, have stated all along they needed 91 octane. Lately, the 2012 and 2013 RX350 have reverted back to only needing 87 octane. This is noticeable by the drops in horsepower and engine torque ratings for the RX.

As a result I think much of the confusion is that it really depends on which RX you have. As you have a 2013 you can safely use regular fuel in your RX with little in the way of worries. No, you will not damage your fuel sensors. Besides, using a lower octane is not really how you damage a fuel sensor. If you are worried that the fuel you use does not have enough cleaners or additives then you can dump a 20oz bottle of Chevron Techron once or twice a year in the tank and that will clean things up for you.

Will use see any benefit from using a higher octane fuel? Some will say you may get higher MPG and somewhat better performance. Very subjective and something you can test yourself over a period of time.

aznboi88

thats for the help, very great responses. Probably going to stick with the 87, and it seems true that one will get better MPG, but not as much as one would think. Once again, helpful responses.

rayaans

WOW 87 octane is so low! Here in the UK the normal is 95 octane and premium for us is 97 octane. Wouldnt trust putting anything under 90 octane in the car to be honest.

CanadianRX

read 3 posts up:

Keep in mind that like many things here in the US, we use a different rating system when it comes to gasoline octane. The pumps may read 87/89/93 octane, however, that is using the AKI system. The same rating system is also used in Canada. The RON values are 91/93/98 if memory serves me correct.

vlad_a

You can pretty much use any gas in '13 RX350. You can mix all you want. When you pour 89 at a gas station, it is actually a mix of 87 and 93(91).
The ECU will compensate for any variations and will set timing accordingly. Your engine will be fine, so will be all of sensors.
Of course, if you get poor gas, which has nothing to do with its rating, that's a whole different story.

rayaans

Oooh yes, missed that. Im so stupid sometimes! I think its poor general knowledge, always been more of a book nerd! Its still lower than over here but then again, we do pay £1.40 a litre so about $2.10 dollars a litre!

kryten

Running my '13 on 87, so far so good. Better than my old Acura that needed premium!

Cruiter

Well, the true bottom line depends on where geographically you live on the planet. This link will explain the difference in what octane values mean around the world. It should clear up a lot of misconceptions. http://www.newworldencyclopedia.org/entry/gasoline .

Here's another myth buster link http://www.nicoclub.com/archives/gas...ane-myths.html The bottom paragraph describes what can happen if you burn regular in an engine designed for premium.

steveski

You can mix the gas if you want to, it would just increase the octane from regular. I had the same question and researched the answer as I did have fuels and lubricants in college. Hers is my finding;

There has been a lot of confusion in the dealerships on what type of gasoline the various RX models should run.
I just bought the 2012 RX-350, and one reason for the purchase was the use of unleaded Regular Octane 87 (R+M)/2 (USA Method), saving 20-25cpg. The manual fuel type describes the requirement use of two octane numbers; these depend on where you live in the world and what octane method is used. These two octane methods are actually the same gasoline tested using two different methods.
One is the use of octane rating of 87 using the test method – (R+M)/2, this method is used in the US and called the "Anti-Knock Index" (AKI) method. This method AKI = (RON+MON)/2, you will see this on the pump showing the combination of these two methods as (R+M)/2), it is an average of the Research Octane Number and Motor Octane Number. This is the method the US refineries use in making the gasoline octane values. So you can use regular unleaded gasoline rated at 87 octane in the USA. If you want more detail on the test method of these two methods, Google "Gasoline Octane Ratings".
The second octane value noted in the manual for the 2012 RX-350 is 91 Octane (Research Octane Number, RON Method). This Gasoline octane rating method is used in Europe and Australia. The 91 Octane (RON) rating and 87 Octane (AKI) = (RON+MON)/2 are different methods for the same regular Gasoline. So for the US 87 Octane rating is good. I will probably run 89 Octane, which will help when I tow my small boat.
Note that this is minimum acceptable octane rating for the 2012 RX-350.
Hope this is not to confusing. Mike