Fuel Octane for 2000V6

Here in NE in winter Ive been getting good power and mileage by running 89 Mobil, Shell and Irving. No off brands. Friends run 87 as cheap as they can find it. Just curious what anyone has to say especially long distance winter driving.

 

I have always stayed with the plain 87 octane fuel per Toyota's manual. Going higher one will not get more energy from the higher octane fuel so I don't see the need. Now if you can get your hands on ethanol-free fuel, then yes you should realize more power from the fuel. Again octane does not enter this.

Specific to winter times, I don't leave the fuel tank to remain empty for an extended period to minimize the potential for condensation.

 

Modern Engines with an ECU retune themselves (advance their timing) for whatever octane you use up to a certain point. You won't get any more power really. Just buy the 87.

 

I've seen this on a Porsche but a 2000 Toyota does not have this capability. If ignition is being controlled by the engine ECU and if the vehicle that has been designed for an 87 octane fuel is filled with premium, there will be no difference in the timing and you will have wasted money.

In the high mileage engines and before knock sensors were invented, we'd use higher octane fuel as a stop gap measure to minimize and/or eliminate engine knocking. On an engine that has a knock sensor like a 3rd gen 4Runners, it would be interesting to see how often they're activated. I've never looked into this but perhaps the OBD keeps a log. Anyway if there is a log file and if it begins to show an uptick in the frequency of the timing retardation, then there would be a benefit to switch to a higher octane fuel.