Our first tank full of gas in our new NX350h. I am sure the dealer put 87 octane in there at delivery and with gas prices so high, we were going to using 87 octane. For the first fill up, I wanted to try premium which is 93 octane here. Within about a minute or 2 after the fill up, I could immediately feel the differences in power and engine noise/vibration. In my opinion, this engine is tuned for 91 octane and prefers it. We only drives about 3000 miles a year so cost is not a big factor. We will be using 93 octane for the foreseeable future.

 

I just recently filled up my tank with 89 for the first time in over 2 years. I fill up in Costco all the time and they only have 89 and 94, so I always get 94. Anyway, I was at Costco buying stuff and did not really need the gas as I still had half a tank left, but I figured the prices will go up probably, so since I am already here, might as well fill up. Then I see the price of 94 is almost $4 so I was like well I already have half of the tank of 94 I will just get another half the tank of 89, witch when mixed will end up being somewhere in 91 range and I save a few bucks in process haha

 

Shoot… our local Costco went up again from my last post on the Gas Prices Thread in Car Chat.

Somebody pointed out for those of us that endured the over $5 /gal back around 2007-2011, would be like paying $15 /gal by today’s standards.

So… we are okay with it for now but if it starts to climb toward that $10 - $15 range, we will feel the crunch for sure!!

 

93 octane here in New England is $5.50 a gallon. I mix different octane all the time. The Shell premium is supposed to have more additives than regular.

 

I didn't feel any difference between 87 and 91.
same sound , same vibration, same power.

 

https://support.lexus.com/s/article/...rade-shou-8129

Lexus agrees, as that is their recommendation. Before the wolves come, not required but recommended.

 

Great — Thanks for the link. I kept it for future reference as you stated without stating that very subject comes up quite often in multiple forums.

 

Great time to own a hybrid. Any car I own I use whatever the fuel door reads.... nothing less unless it's the only gas available .

 

This hybrid system is much better than my old RX450h from 10 years ago. The new lithium battery in the Lexus hybrid system works great. Engine start stop is almost un-noticeable and this NX hold a line very well on the highway, precise steering. Acceleration is good considering the high gas mileage. Overall, this NX hybrid is a big leap from the last gen NX hybrid.

 

Pure placebo.
That's the time needed for your new fuel to just travel to the engine...

 

it would not make sense for Lexus to recommend higher octane if there is no difference. The Lexus marketing department must know that using regular gas is a big selling point, especially with gas prices sky rocketing.
When you runout of gas, it takes a few minutes for the gas to get to the engine to start. Same scenario here except the NX has dual injection, high pressure and low, so it might be a bit quicker to get to the new gas. The NXh’s engine has a 14 to 1 compression ratio, so it could definitely take advantage of the high octane.

 

Lexus has all the reasons in the world to say "Hey we're not poor rav4 drivers, we can also use higher octane fuel... and also look at these 20" rims".
Just to be sure that you'll be feeling the exclusive nature of your ride

BTW: it's direct and port injection, and having twice as much injectors doesn't mean you inject twice as much fuel lol.

 

You do know that direct injection is higher pressure right? Regardless of that fact, gas only takes a few minutes to get from gas tank to engine even in port injection engines.
Do you think the difference between a NX and a RAV4’s powertrain is the expensive gas that does nothing as you say?. The NXh using premium gas has 21 more horsepower than the rav4 hybrid, that is a pretty substantial increase.
Even our salesman use 87 gas as a selling point for the hybrid, most people know high octane gas is a negative selling point..Engine tuning could absolutely take advantage of higher octane gas even within the same engine. Lexus has a different ecu program from the rav4 to do just that, almost like when you chip a car to increase performance. With a compression ratio of 14 to 1, putting 87 octane in it means the timing is always being retarded in the ecu.

 

Lexus recommends Top Tier gas. This means you can get quality gas, regardless of octane, at a few stations that may be cheaper than Costco. We hit Quik Trip as often as Costco. Yes, we use the highest octane available. Although Costco's 5% reward on Costco gas is hard to beat, the lines can be awfully long.

 

I am just saying: how can you feel improvement within a minute or two, if the new gas itself takes a few minutes to reach the engine.
On top of that the ECU might also take a few minutes to adjust.
Then a user would probably take a few minutes too to notice a difference.
And that's assuming you leave the gas station with a vigorous launch

To me it's pure placebo.