octane: u running 91 or 87?

[grammasfj]

I've only used 87 in my 2007 FJ--runs great -no pings and plenty of power--and gets good gas mileage since its past the break in period.

[grammasfj]

First 2000 miles gas mileage was awful!

[TacomaOffRoadGrl]

Is the FJ engine not the same as the Tacoma?

[Jason.MZW20]

Originally Posted by TacomaOffRoadGrl

Is the FJ engine not the same as the Tacoma?

It's exactly the same. The 1GR can run on 87 octane or higher. Toyota recommends 91 for best performance, however. With any octane, the ECU will determine how far it can advance the ignition timing. Obviously since 87 octane is more explosive, the ECU cannot advance the timing as far as 91 octane and the knock sensors actively detect pinging or detonation. Since 91 octane can let the engine achieve more timing, it creates more power, therefore, 87 octane runs the timing retarded since it cannot achieve the maximum amount of advance the ECU specifies. As the compression ratio of an engine increases, the more performance you'll lose between 87 and 91, but since the 1GR only has a 10.0:1 ratio, it's not too terrible.

So:

87 octane
236hp @ 5200rpm
266lb-ft @ 4000rpm

or

91 octane
239hp @ 5200rpm
278lb-ft @ 3700rpm

You get 12lb-ft more 300rpm sooner. Trivial, but it helps. Most dynos I've seen of the 1GR on 91 octane show 285lb-ft though.

[ToyotaJoel]

I've owned my FJ for over a year now and have only filled it with 87 octane. No pings, knocks or lack of performance. Also, the Dealership filled it for my courtesy fillup with 87. Most do.

[marylandstrong]

my wife has the 07 fj cruiser. She's been running the cheap stuff for more than a year and no pinging or knocking has been observed. I have been using Mobil 1 oil however. But all things considered, your not going notice any change. Mpg has been around 17 city- depending how heavy the foot is of course... My 08 tundra 5.7 gets around 15 to 16 - not too shabby. Best of Luck with the fj.