04/05 4runner with 89 octane?

Anyone have any problems running 89 octane in their 04/05 4runner? I think most of us are using 91 or above...right?

Mine runs real well on 87? (3900 miles)

89 octane is great without having to spend big $$$ on gas

Hmmm...don't they recommend 91 or 92, but it runs fine on 87 without any pinging?

Modern engines can use a wide range of octanes. The ECM detects any pinging caused by low-octane fuel and retards the ignition timing to permit use of the lower octane gas. If you fill up the tank with high octane gas, the timing won't be retarded any more and your mileage and performance will increase.

Above a certain octane, you don't get any further benefit and you are wasting your money. Below the optimum octane, you are getting lesser performance and worse gas mileage. The way to find out your optimum octane (best performance without using higher octane gas than is necessary) is to measure your gas mileage over a few tanks of a specific gasoline octane. Use the lowest octane gas that gives you the best possible mileage.