More specific🤔 seems pretty clear to me.

 

I should be so lucky to get those gas prices here No such luck! I use 91 just because I know it keeps my engine cleaner and don't drive a great amount of miles so at the end of the year the savings for me are a non issue. I did use 89 on my wife's subaru, but only for the additional additives to clean the cylinder, piston head & valves. Thankfully here in Ontario our premium (91) doesn't contain any ethanol, another reason why I use it.
Keep well

 

Why would you buy a premium prestige car and then fill it with crap fuel to save a few cents? the performance suffers and then all these people are saying its not running smoothly or hesitates ... It is beyond me ?? Its like the folks saying they are going to buy a Toyota oil filter and get it serviced at Toyota because they think it will be cheaper .
If you cant afford to run it as it was designed don't buy it in the first place !

 

Lexus uses Toyota oil filters. Hilarious you think going to the Lexus dealer and paying twice as more for an oil change as opposed to going to a Toyota dealership and you thing you get a better oil change. REALLY!!! Experts state they is no difference in mpg using regular and such a slight difference in performance that the driver does not notice any difference. Used regular when premium was required for many vehicles for almost a million miles of driving. Have never had one issue and also never noticed any increase in gas mileage. The little bit of loss in performance, I could care less. It is a Lexus not a Porsche. If it makes you feel better spend the extra $$$.

I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4

From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.

Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
__________________

 

Premium gas is not required for the RX 350, but the salesman said premium gas help "performance" a little bit.

Do you use regular or premium on your RX 350? is there a major difference?

Thanks.

 

No, we're happy using 87 octane. Saves money, and the car drives really nicely.

 

Premium is a waste of money. This is almost a religious thing so be prepared to hear all sides of this argument.

 

Will my 2017 RX 350 run better on premium gas?

 

Maybe. It is tuned for regular (thanks goodness) so no guarantee premium would make any additional gains.

why don't you do some tests to find out? 5 tanks of each grade to see.

 

I think there is a thread on hesitation that someone used mid to premium grade to solve the hesitation issue.

 

My '16 does not run any better on premium than on regular. It is not smoother, faster, nor more economical.

 

That's what I've always been told, so I've never used premium in any of my cars.

 

Engines including the 3.5L V6 in the RX350 are tuned for regular Octane Level fuel and
there is NO benefit to paying for and using slower burning Premium fuel. The 2011 model
year and previous RX350's did recommend Premium.
note: the 2010 to present RX450h Hybrid Does Require Premium.

 

The RX-450H does not require premium gas! It is recommended in the the owner's manual but not required! My RX-450H came new from the dealer with regular 87 octane 10% ethanol gas. It runs great on regular and I do get a bit more gas mileage on 93 octane but it works out that the extra MPG is not really worth the extra gas cost.

 

gregjhonda, to clarify, the owner's manual states 93 is required. It's been that way since the 450h came out in 2010. The octane level was changed from premium to regular (87 or higher) beginning with the 2012 RX 350. You're obviously free to choose whatever fuel grade you want on your 450h. But I suggest continuing that discussion here due to the difference in octane requirements. It's not necessarily relevant to RX350 owners considering using mid or premium.

The thread is being reopened. Everyone is free to share their experience and opinion. But please keep the posts amicable.