kcdehart
New member
Hey all,
Just wanted to share some findings that seem to be related to gas grade.
When I first bought my 4 Runner, I'd read that running 87/89 was fine, even though it could make use of (and would run best on) 91. So, I ran 87 for several months. The truck would have an issue where, at idle with the brake applied, RPMs would drop to 450 or so and a piece on the underbody (it looks like a shield between the driveshaft and exhaust) would rattle obnoxiously. It sounded like one of those old-fashioned alarm clocks with bells on top. This was at nearly every stoplight if I left it in drive (I would switch to neutral and the idle would go up and sound would go away.)
In January, I towed a trailer w/ motorcycle on it 3 or so hours and decided to run 93 for power and gas mileage. With 93, after having 87 for so long, I noticed a definite increase in throttle response and a small bump in gas mileage (from 18 highway up to ~20 highway). So, I decided to start running 93 more often since it seemed to have some benefits.
The other thing that I noticed, after running 93 for a while, was that the idle drop at stoplights was completely gone. The idle now stays steady at 600rpm.
Just an interesting find that I figured I'd share. Even though there aren't huge differences in driveability between lower and higher octane gas with these trucks, the higher octane stuff definitely performs better.
Just wanted to share some findings that seem to be related to gas grade.
When I first bought my 4 Runner, I'd read that running 87/89 was fine, even though it could make use of (and would run best on) 91. So, I ran 87 for several months. The truck would have an issue where, at idle with the brake applied, RPMs would drop to 450 or so and a piece on the underbody (it looks like a shield between the driveshaft and exhaust) would rattle obnoxiously. It sounded like one of those old-fashioned alarm clocks with bells on top. This was at nearly every stoplight if I left it in drive (I would switch to neutral and the idle would go up and sound would go away.)
In January, I towed a trailer w/ motorcycle on it 3 or so hours and decided to run 93 for power and gas mileage. With 93, after having 87 for so long, I noticed a definite increase in throttle response and a small bump in gas mileage (from 18 highway up to ~20 highway). So, I decided to start running 93 more often since it seemed to have some benefits.
The other thing that I noticed, after running 93 for a while, was that the idle drop at stoplights was completely gone. The idle now stays steady at 600rpm.
Just an interesting find that I figured I'd share. Even though there aren't huge differences in driveability between lower and higher octane gas with these trucks, the higher octane stuff definitely performs better.
