Rx questions
Pit Crew
Joined: Jan 2021
Posts: 160
Likes: 127
From: PA
According to the owner's manuals, 87 Octane (or higher) for the 350; 91 Octane (or higher) for the 450h.
The fuel tank for the 350 is 19.2 gallons; for the 450h. the fuel tank is 17.2 gallons.
Driver
Joined: May 2021
Posts: 60
Likes: 20
From: OR
I drive a 2021 RX 450h and use regular grade fuel and it's been fine. The engine and transmission are the same as the 2016-2019 Toyota Highlander, which does not require premium fuel so I don't really see the point.
Thread Starter
Driver
Joined: Feb 2022
Posts: 50
Likes: 18
From: SC
What is the MPG a difference you are seeing?
Pole Position
Joined: Jun 2010
Posts: 3,172
Likes: 1,716
From: NC
I currently have my seventh vehicle (current 2017 RX 450h) that required premium gasoline of which I have used regular. Tried many occassions on each with premium and noticed absolutely no difference. I remember a thread awhile back here on this issue and a member swore his vehicle drove better and even said the transmission shifted smoother. Each vehicle drove over 100,000 miles before trading in or selling. Had ZERO engine issues. Experimenting with the other two levels, I have noticed zero difference in gas mileage or performance. I have used 87 in cars that have required premium for over a million miles and have not had one problem.
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.I have researshed on the net and can not find one article that confirms the need to use premium except in a high charged turbo engine. So before the pissing contest starts please please if you want to use premium please do.
Good article and You Tube clip on gasoline grades.
https://www.consumerreports.org/car-...h-extra-price/
https://www.youtube.com/watch?v=FPPkPAbzwbU&t=508s&ab_channel=CBCNews
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.I have researshed on the net and can not find one article that confirms the need to use premium except in a high charged turbo engine. So before the pissing contest starts please please if you want to use premium please do.
Good article and You Tube clip on gasoline grades.
https://www.consumerreports.org/car-...h-extra-price/
https://www.youtube.com/watch?v=FPPkPAbzwbU&t=508s&ab_channel=CBCNews
Last edited by Freds430; Apr 16, 2022 at 04:50 AM.
Pit Crew
Joined: Jan 2021
Posts: 160
Likes: 127
From: PA
Overall, the difference between the two is about 10 MPG (adjusting to the same mix of highway and city driving). Overall, I'm getting about 36 MPG in my 450h. That's based on a mix of roughly 80% highway/20% city driving. A note of caution, however: I don't drive like a maniac. I don't speed on the highway, and I don't race from red light to red light in the city. YMMV!
Intermediate
Joined: Jan 2010
Posts: 419
Likes: 55
From: PA
I am on my 4th RX450h and have used both regular and 91 in all of them. I keep logs of calculated mileage (not the display) and I generally got slight improvements in mileage that was only in the tenths of a MPG. I now have a 2022 and use regular. The dealership told me to use regular. When I purchased my 2017 the dealer told me they only put 87 octane in the tanks at the dealership.
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If you check the FAQ at the top of this forum you’ll find answers to common questions like these. Example linked there https://www.clublexus.com/forums/rx-...equired-5.html
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