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So what's the outcome? Is running on Regular OK? Will it kill my engine? Will I violate my warranty?
 

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I made the switch about four tanks ago and I can see no change in performance. I ran Super for a year(32k miles) and decided to give it a try. What I did find was about $5 in my pocket rather than in my tank.
 

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I dunno, I figure the manufacturer doesn't say to use it because requiring premium sells more cars...

The Straight Dope: What's the difference between premium and regular gas?

I noticed about a 2-3 mpg drop in gas mileage when I've tried it in my car, which pretty much canceled out any savings. I doubt the power loss is anything your butt dyno will notice, but it's there too. Whether it's necessary is determined by the compression ratio of your motor, and even a knock sensor means knock has to happen before the computer adjusts...

It's like anything else; you can probably exceed the trailer weight by a bit, drive on your tires past the wear bars, or whatever. If it's worth the risk on a $30K vehicle to (maybe) save a few bills, then go for it, but really, you bought the wrong vehicle if you wanted to be thrifty :p

Other than running an engine without oil, there is probably nothing that you can do that is more detrimental to an engine than detonating it. In an ideal combustion cycle there is a controlled burning of the compressed fuel and air, but during detonation there is an exploding of the mixture with a instantaneous release of all its energy, regardless of where the piston is in its stroke. The timing of the auto-ignition will have a direct effect on where the damage takes place.

Detonation very early in the compression stroke is usually the silent killer that goes unheard by the driver. This form of combustion usually results in rotating assembly failure by attacking the connecting rods and bearings. Detonation that comes nearer to TDC or slightly after is usually heard as pinging and will likely result in the burning of the piston or the lifting of the ring land from the piston. The force from the colliding of the multiple flame fronts can be likened to the wake of two boats travelling in opposite directions on a lake. When the two wakes meet, they usually peak and absorb the energy of each other. The more dominant wake will still have some leftover energy and will proceed weakly in its original direction. The same holds true for colliding flame fronts in a cylinder. If you have one flame initiated at the spark plug and another started independently of the plug, usually the spark-initiated front is the dominant one. As the two flame fronts collide, the pressure in the cylinder rises from the compacting of the molecules. Historically, the normal flame front has enough energy to run over the abnormal one but uses a lot of its energy to do this. Add to this that the abnormal combustion has consumed a portion of the combustible mixture that filled the cylinder, and the least result is a loss of power, if not a damaged engine.
 

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I give up.

DEWFPO
 

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87 octane is fine...the cmputer adjusts itself for thel ower octane.....running the cheaper stuff will give you a slight drop in mileage (ive seen it got from 17 to 16 in town and 23 to 21 on the highway) but you wont notice much else. I only use the good stuff when I tow my snowmobile or 4 wheelers.

The computer adjusts.....thats what its made to do....and Toyota said it woudlnt hurt.....so why pay for the extra octane if your just doing daily driving.....save the expensive stuff for when your towing or need the hp and torque.
 

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The short and skinny is that Toyota has said it is ok to use 87 octane. The reasoning behind the initial requirement was that the hp/torque numbers published for the 1GR-FE engine in the FJ were done using premium fuel; or some such...
 

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as has been said over and over and over and is true:
87 (or in CO, 85) won't hurt anything. When I run cheap stuff it costs me about $.28/mile - when I run shell premium - it's about $.24/mile. That's about it :)
 

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It takes more than a bunch of people on an internet forum saying "works for me" to convince me. Not saying it ISN'T true, but, especially on a vehicle that hasn't been out that long... If I heard a bunch of people with 200K+ miles saying they've run it consistently, that would be a little more encouraging, and seeing something from Toyota even moreso. Until then, I still see it as:

Premium; definitely ok
cheaper stuff: maybe (even probably) ok, but...?
 

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The TSB says it all, if you wish to run regular gas you can, but there is a chance in lowered engine performance(most people don't even notice it) so basically it is up to you on what type of gas you want to put in the FJ!:bigthumb:
 

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My understanding is that this engine has been out for a while in other Toyota vehicles (Tacoma I believe) and those have been using 87.
 

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Hello room, I have 13,234 miles on my FJ and have always run the good stuff ,but after reading these thread's I put 25.00 of Regular in my tank I can not feel any thing different in power, :rocker: as one of you did say that is 5 more bucks in my pocket ever time I fill up FJ'S RULE :cheers:
 

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Seriously, lets do some simple math, Premium cost an average of $.20 more per gallon. There is a 19 gallon tank in the vehical, with a 3 gallon reserve, so you are putting in 16 gallons. that adds up to aprox. $3.20 extra per fill up and if you only fill up once a week a total of $166.40 per year. Please do your own caculations, I know some of you drive more than others.

As mentioned in other posts, you might see a decrease in fuel economy, and the cost of potential repairs in the future.

To me this is a No Brainer.

Give up your Starbucks and quit crying about it.
 

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Didn't the last of these threads just die? UGH!

Use the regular if you want to get around,
use the mid if you want to get around but stomp the gas from time to time,
and use the premium if you like to think your driving a sports car.

A thing to keep in mind though is the $200 you would save a year using regular would come back in engine repairs. (I go between 15000 and 20000 miles a year). Id rather enjoy the pony's instead.
 
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