Fuel Octane Levels

[Arjuna]

Hi friends

I was going through a Prius service manual that recommended 87Octane petrol (Gas) as the recommended fuel. It also mentioned that 95Octane could beep a dash warning occasionally. It could be the same for RX since it has the same technology in a larger scale. Has anyone analysed the long term saving vs costs such as fuel system cleanups and mileage etc. I am sure there are many threads on this but I am wondering whether there is a long term impact analysis.

Regards

Arjuna

[Jim Nazium]

Hi friends

I was going through a Prius service manual that recommended 87Octane petrol (Gas) as the recommended fuel. It also mentioned that 95Octane could beep a dash warning occasionally. It could be the same for RX since it has the same technology in a larger scale. Has anyone analysed the long term saving vs costs such as fuel system cleanups and mileage etc. I am sure there are many threads on this but I am wondering whether there is a long term impact analysis.

Regards

Arjuna

Welcome Arjuna... Not sure really what you are asking. If you are implying whether or not the cost of higher octane fuel offsets the cost of the fuel for greater fuel mileage, this isn't the case. I have found to achieve greater fuel mileage using regular grade octane. The only time I have found the higher octane to be of any benefit, is during the few weeks in the year where it gets super hot and muggy. On those occasions, I have found the higher octane to alleviate traces of pre-ignition (otherwise known as "pinging") while driving up moderate inclinations typically found on long stretches of highways. Our engines adapt well, but in the extremely humid and hot periods, find the engine mapping to be more friendly towards mileage than to avoiding pre-ignition. Alot of this is all due to the cvt imho, since it doesn't work exactly like a conventional geared transmission.

Cheers,

MadloR

[maseace]

The RX400h recommends 91 octane or higher in the manual, so it must not be a problem.

[RX400h]

The RX400h recommends 91 octane or higher in the manual, so it must not be a problem.

...not our 2006 RX400h manual. It states that regular is acceptable. I use midgrade most of the time but have run with regular during cooler months.

[removeum]

Hi friends

I was going through a Prius service manual that recommended 87Octane petrol (Gas) as the recommended fuel. It also mentioned that 95Octane could beep a dash warning occasionally. It could be the same for RX since it has the same technology in a larger scale. Has anyone analysed the long term saving vs costs such as fuel system cleanups and mileage etc. I am sure there are many threads on this but I am wondering whether there is a long term impact analysis.

Regards

Arjuna

The owners manual states 91 Octane. Remember your RX400 is a six cylinder and not a four cylinder like the Prius.

[lenore]

And from what i gather the early 400h was set for regular and the 2008 was definetly 91ocatane...