Just started looking into the 350h as an upgrade from my 2016 RX 350. I'm reading mixed reports on whether premium fuel is REQUIRED, not just recommended. Most of what I'm reading says 87 was fine for 2023 and earlier models, but the '24 and '25 REQUIRE 91 - but again there seems to be different info all over the place.

Can anyone who has a '24 confirm for me what you use, what you were told, what your manual actually says? Thanks!

 

For the naturally aspirated engines that the RX350h and RX450h+ have Lexus recommends 91 with a minimum of 87 required. For the turbocharged engines that the RX350 and RX500h have, Lexus requires a minimum of 91 octane and warns that damage can occur with lower octane.

I run 91 octane in our 2024 Lexus RX450h+.

 

WellsB is correct, I personally used 87 in my 2023 350h and in my current 2024 450h+.

Cheers

 

Due to the fact that you can only refuel with 10 - 12 US gallons at a time (out of 17.5), you could probably get away with alternating using 93 octane one tank, and 87 octane the next, if you are cheap frugal. We have filled with 87 a couple times on our turbocharged 500h without any discernible differences in MPG, running, or pre-ignition.

 

Filling up a tank of 93 with 12 gallons of 87 gives you 89 octane. I certainly would not recommend it where 91 is required.

 

Split fill 60/40 with 93/87. Saves about $4 for a minute of my time.

 

Just purchased a 350rx and sales said that Lexus recommends 91 for performance but it is not required and will not damage the turbo engine

 

Don't know about you - but I know for a fact that Lexus (sales, or even service) will tell me anything they can say to make sure money changes hands. Once money changes hands, of course, you are on your own.

 

For 350h hybrid MY 2024/2025 is same as 2023 87octane minimum, 91octane recommended for max performance. All owners manual are online.

highlander hybrid have same drivetrain/electric motors does not carry premium fuel recommendation is rated at 243hp vs RX rated at 246hp. Note this is max hp likely RX will have more power through out rev range using premium gas but I do not feel difference and did not buy this car for performance.

You can use 87 without any concerns, non-hybrid 350 REQUIRES 91 as it is turbo charged.

 

Does premium fuel do anything for the 350H? I just got my 2025 Rx 350h. The manual listed both 91 and 87. It was odd because there was no description or guidance why both are listed.

the online manual looks different from my paper manual. Also my gas cap says 20% ethanol max. The online manual says e15 only.

 

Our 24 350h we have now since March 24 and 12k miles. Regular gas only 87. Drives flawlessly.

 

I must’ve looked at the cap in low light the other day, it in fact, has a line drawn through E20-E85. My bad.