High-revving 3.5L and long-term reliability

Wow, interesting stuff there. Makes me feel a little bit better about long term reliability.

 

RON91 is 87 octane.

 

As it is not specified either way, typically octane ratings are published RON+MON/2, so I assume it as such. As is the gasoline you buy at the pump RON+MON/2.

Edit: At least this is the case here in the States. I see you are in Canada and I am not familiar with their standards.

 

Don't just assume things. The specs you posted are from Japan, where they publish RON numbers only.

Look at the 2jz-gtte spec sheet - 96 RON which is 92 octane. http://www.mr2.com/files/mr2/techinfo/Random FSM Data/032jzgteVS7mgte.pdf
Now, a spec sheet for the 5vz-fe and 3vz-e 91 RON, or 87 AKI octane. http://www.mr2.com/files/mr2/techinfo/Random FSM Data/engine5vzVS3vze.pdf

Trust me, this specification is in RON, not AKI.

EDIT: LOL Canadian standards. Same shit. Except we have an imperial gallon which is 4.54 litres vs your 3.78 litre gallon. (and that no one on earth uses other than car manufacturers that use it to boost their "Miles per gallon" ratings... friggen' crooks), and the metric system vs. imperial.

 

I have around 9 fill ups in my 3rd gen, all with 87 octane. Maybe I should try midgrade for shits and giggles and see what happens to my fuel mileage and seat-of-the-pants feel.

 

Your acceleration will be slightly quicker thanks to the slightly lighter wallet.

 

15 years would be nice. Im currently at 8 years with 140K.. so at 15 years, i should have 262K miles!!

 

I figured as much. 89 made no difference in my 1GR. I'd be curious to drive with 87 and datalog the amount of timing that gets pulled versus 89 though.

 

Typically, when a specification is listed RON or MON, it is specified as such. As you have shown in your 2 examples. When it is not specifically listed, it is commonly assumed RON+MON/2. Furthermore, 11.8:1 compression ratio requiring 91 (RON+MON/2) octane fuel makes sense, direct port injection or no, while 87 (RON+MON/2) does not (without crippling the engine's performance).

 

I usually only put 12,000 miles or so a year on my truck. 262K miles isn't uncommon for Toyotas however.

 

I wouldn't worry about an engine designed to for high rpm.
I might worry about an engine designed for low rpm revving high...

 

Japan always lists RON. Is it only in the USA that you make assumptions that everyone does everything the same as you do? Canada does, but Japan does not. If we used your logic, Supra's would require 96 octane to not pop ping and explode. And every 4runner/tacoma from 1988 to 2004 would need 91 octane to run properly. I've clearly proven you wrong but you choose not to see the logic.

I know where you are coming from on 11.8:1 C/R, however you are thinking 90's EFI technology, not 2015. The 2GR is not your daddy's 22re.

From the web:

In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from our own... So, like every other measurement system it seems that everyone else uses a different scale than we do, but unlike most other instances where we have had the good sense to create different units of measure in this case we all use the same name...
Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating... Interestingly, to further complicate things it would seem that our own AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number... So, to recap our methodologies for measuring gasoline's octane rating are different, but share some common elements...
So, with the commonality of RON in mind a good rule of thumb is as follows, multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent.

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

 

All you Canucks are funny. We're having a civil disagreement over a printed specification on a data sheet, and what is this, are you trying to insult me? I am proud to be an American, and I don't give a fuck where the document was created. Typically if the spec is RON then it is stated as such. Like in the examples you linked. And while on that subject, the 5ZE you refer to with RON 91 (87 AKI) has a compression ratio of 9.6:1, further illustrating my point.

So, why then would an engine (2GR) with a compression ratio 2.2:1 higher use the same low grade fuel as the engine (5ZE) with 9.6:1, and not expect detonation?

Listen, I am not saying that these engines won't run with the lower grade 87 fuel, as they will run fine. I am saying however, that they will be limited under high loads and will run below their full potential, as the ECM protects the engine from knocking. And the same goes for the beloved Supra.

End discussion.

 

LOL i only did it because of your Canadian comment, knew it would get you riled up

Boomshakalaka.

 

Well, there you go. Thank you AAChaoshand.

I will concede, the Min octane requirement point, but will say the source for specifications I found (New model introduction documentation to Toyota dealers) was ambiguous. However, please don't think your engine will meet it's full potential using low grade fuel. I will run 91 RON+MON/2 fuel in my truck, as I am quite familiar with the ECM dialing back the ign/fuel to avoid knocking when towing or any high load for that matter. Please use whatever fuel you are comfortable using in yours.

 

50/50 mix of premium/leaded race gas is the only way to go.

 

Here you go... math to help ......

 

Reported for for racial overtone.