Htony

Unfortunately timing can't be retarded indefinitely. There is a limit what computer can do. Drivability is one thing, keeping engine clean with
premium fuel is another thing. Premium has mre detergwents.

DZhao

Hi All,

Finally closing on a CPO 2017 RX 350 F Sport with 22k miles with all the bells and whistles at 37,800. Hopefully thats a good price.

What kind of due diligence i should do with the car when i pick it up? Feed it 91 octane gas for a few thousand miles? Feed it gas cleaner?

Thanks all!

ravenuer

Assuming it runs fine, no need to do anything special. Feed it any octane you want, as long as it's 87 or higher.

1Louder

Congrats!! I agree, no need to do anything special. If it's a CPO it will be all caught up on it's maintenance. As far as gas goes, as you can read here there's no shortage of opinions on gas I'd be inclined to use 91 for a tank or two just to get a baseline for MPG and how it drives. Then switch (if you want) and then you'll have something to compare to in order to know if it matters or not.

RXRunner

We use 87 Octane with 10% ethanol in our 2016 RX350. Consistently averaging 23 mpg city and highway driving. Used the same octane gas in our 2010 RX350. Never had any drivability or engine issues.

rxtimes2

I think more important than the octane is the engine cleaning agent. Top Tier fuel is recommended, and according to Consumer Reports, makes a difference on engine performance.

lex_rx

When Canadian dollar was close to parity, I would fill up with premium when travelling in the US as gas was “cheap” especially at Costco. Did this with both 2004 and 2011 RX. Didn’t notice driving difference with regular and premium on both vehicles.

exonw

Shell Regular 87 + STP complete fuel system cleaner every 3 or 4 months.

autotech13

I use Shell 93 octane for now, but will try Shell 89 octane and see how it runs. I get no hesitation at all, even with regular 87 when I first got it. 2018 RX. I think if guys are having hesitation problems, try a Top Tier gas.

blayze1983

Why anyone would pony up for Premium when the manufacturer recommends Regular is beyond my comprehension.

Cocal

I've never experienced any of the hesitation problems, but I've used 94 octane from day 1 !
It's not only that but the whole fuel system and valves keep cleaner, now if you only keep a car for 3yr or less this is moot.

Cocal

And here we go again reading things that are NOT written, where do you see a RECOMMANDATION in this...... one may use 87 (Research Octane Number 91) or higher
To me that's more like a warning, not to go below 87.

dibl

I would not characterize "87 (Research Method 91) or higher" as a recommendation to use Regular (page 700 in my user manual). Nor is it evidence that the engine runs best on 87 octane. It just means you won't hurt it by running 87 octane.

mckdaddy

Not much availability of 93 octane in my neck of the woods, but 91 is prevalent so I use it.

Cocal

Neither does mine, however in last year's posts there was a poster that got a note from Lexus saying that all their tests are done on premium, but don't know if 91 93 or 94 octane, I too was told verbally by Lexus that they use premium, but they don't say so in the books as it would be detrimental to sales in Northamerica. There was a poster from Australia who reported that his manual recommended premium.
In the end one does whatever one wants, but there are a LOT of people who mistake warnings for recommendations.