colrhino

We just bought a 2011 RX-350 to replace our "old faithful", a 2002 RX-300 w/185k miles. My question- I used to run regular 87 octane in the 300 w/zero issues.... The 350 wants 91? or higher- what happens if you don't feed it properly? Any long term harm done?

kitlz

colrhino, congrats on your RX and welcome to CL. You might want to read through the gas thread to get some idea about mileage, including input from a few members that used lower octane. If you had purchased a '12 instead, you could have used regular. But I would follow the required octane of 91 or higher on your '11. There's no sense in chancing any long term damage.

colrhino

thanks kitzl, I'll do just that.

Sevn86

Yeah, ive filled up reg once just to try it out and performance dropped. I felt it didnt run as smooth so I just get 93 octane always.

konradsa

I agree: Use what is recommended by the manufacturer, which means premium -2011 and regular 2012-. Any effect you would feel in a 2012- by using premium over regular is likely placebo. You may also be able to use regular in a -2011, but the engine was not designed and optimized for this.

bextreme1

I've been using regular in my 2010 Rx since it was new. I have no problems at all.I have tested using premium and found no performance difference or noticeable change in gas mileage. I was told by and SA that the engine adjusts itself automatically to the octane which is why we don't get the pinging we used to get in older cars.

dctex99

Hey you could save a few bucks going back to dino oil too; and maybe find some cheap Rayon Tires.....lol

RX330inFL

I prefer to go with polyglas tires as they are period specific for a number of early '70's muscle cars.

bextreme1

I suppose you did everything your mother told you to do! I'm sure you wash yours everyday so you keep it in good shape for the next owner. If you like throwing your money away, that's fine. I don't throw mine away. Besides, I'm not keeping my RX for 100K miles. I'll trade it for a 15 when they come out. I put the dino oil in my old corvette and when I want a thrill I drive it! I don't put premium in it either.

sdwtchlvr

iTrader: (1)

Use 91 octane for your 2011. It makes a difference. Maybe not something you can see/feel every day but your O2 sensors and cats will thank you down the road as will your wallet. 91 octane burns cleaner. If one can afford a $45k car, then it seems like spending an extra $4 per fillip to use the proper fuel should be manageable.

dman00001

91 octane gas burning cleaner is an urban legend. It burns no cleaner, or no dirtier, the 89 or 87 octane.

http://www.nicoclub.com/archives/gas...ane-myths.html

http://www.consumer.ftc.gov/articles...ctane-gasoline

konradsa

That's probably true, but I would still stick with a 91 or higher for a 2011. The car was designed with that in mind. Even thought there are no visible changes to engine on 2012, there may have been some subtle software tweaks to account for 87 octane gas. So I would stick with whatever the manufacturer recommends, also with respect to the general and powertrain warranty.

colrhino

Okay, now I'm conflicted on what to actually use with regard to the octane rating of the gasoline for the 2011 models. Seems everyone has had a different experience with using the different fuels. I understand the mfg'r recommends the 91 or higher octane, but others have had satisfactory results with 89 or even 87? Maybe the fall back while it's under the remainder of the factory warranty is to use what the owner's manual specifies?

BertL

OP, it just comes down to what Y-O-U are most comfortable with and how accepting or adverse to possible risk you are. No one here can answer that for you. You know the facts in what the manufacturer recommends for your RX. You've read that some others choose a different path, because they are comfortable with their decision.

Personally, I follow what the manufacturer of my vehicle recommends. I would expect them, as the designers of the vehicle, and those that are accountable for warranty expenses, as well as long term customer satisfaction with their product to know better than I, some publications, online forums including CL, or any other well-meaning (or not) people may suggest.

It's time for you to decide on what octane you use when you need to fill up your tank the next time. What is your decision?

kitlz

I have to concur with BertL. The decision is all yours to make but by using 91 octane you will maximize your RX's performance.