Octane for fj cruiser



the gas cap and other things recommend 91 octane for fj cruiser. is it really necessary??


if you want your fuel economy and engine life to be at it’s best, yes. Your car will run on 87, but i could lead to damage down the road.


If it says you SHOULD use it, then using it should not hurt the car, but it will reduce mileage, eliminating any economic reason for using it, and it will reduce power. If it simples says the car requires 91 octane, then failure to use it means you can add engine damage to the list of reasons why you should use it and there is no way the lower cost of fuel is going to pay for the engine damage.


If a car requires/recommends premium fuel then you will see improved power, engine response and fuel mileage when you opt to use it versus regular gas, making the extra expense a wash. It’s not like these engineers make these recommendations on a whim. I want to emphasize that you will not see these improvements unless your car was optimized to run on premium fuel. Putting premium in a Toyota Corolla will help nothing.


RECOMMENDS means just that, not required but should be used for best performance and usually fuel mileage. REQUIRED means you have to use it otherwise some ill effects will likely occur.


It will run on 87, but it will run better on 91. If you use 87 octane the knock sensor will retard the timing which will lower the power output and raise fuel consumption. It’s unlikely you will save any money using regular instead of high test. It never failes to amuse me how people can spend alot of money on a nice/expensive car, yet balk at the idea of caring for it properly. For example last week I was filling up and at the pump ahead of me sat a new (2007-08) MB S550, an $80k car. The owner finished pumping and drove off. I noticed by the price per gallon display on the pump that he had filled up with regular. I got a chuckle out of it.


one other thing . we live at 7,000 ft. above sea level. does that make a difference??


Here’s another way to look at it (with approximate numbers):

Assume your car has a 20 gallon tank and gets 20 mpg.

If the lower 87 octane is 20 cents/gallon cheaper, then you save $4.00/tank. However, if that lower 87 octane decreases your car’s mpg by 1 mpg (down to 19), then you’ll need another gallon per tankful to drive the same distance.

Although you saved $4.00 when you filled up, with gas near $4/gallon it will cost you an extra $4.00/tank to drive the same distance.

Why deal with all the drawbacks of lower-than-required octane when such a small drop in mileage erases all the money you think you’re saving?


Didn’t know you were at 7,000 ft. Yes that does affect things a bit. You can drop from premium to mid-grade (89 octane) and you’ll be OK. I still wouldn’t drop to 87 though.


You have the same engine as I do in my 4runner. It is RECOMMENDED to use 91 Octane…but NOT required. And at a higher elevation running 89 octane is like using 91 octane at sea level.


If you live at 7000(Denver, right?) your town will have the stations adjusted accordingly. I believe regular is 85 octane up there, not really sure.


Your last statement is untrue. A few months after I got it, I learned that my 1974 Corolla required 90 octane-- putting premium in it made it run much better!


I was wondering would it make any difference if I used 87 octane vs 91 octane for my 98 saturn SC1? I know this isn’t a sports car or a brand new car, but in the past I heard there isn’t any difference if you use 87 or 91 whether if it’s brand new or not.
But my thought is if I use a higher grade fuel wouldn’t that be better for my car even though it’s just a regular car??? Would there be any sort of benefit?


“But my thought is if I use a higher grade fuel wouldn’t that be better for my car even though it’s just a regular car??? Would there be any sort of benefit?”


If you don’t believe me, open your glove compartment, take out the Owner’s Manual, and read what the manufacturer stated regarding the required gasoline octane for your car. Most likely, it requires 87 octane, and as the manual will tell you, there is absolutely no advantage to using gasoline of a higher octane than is recommended.

In years past, higher octane gasolines also had a higher level of detergents in them, but that is no longer the case, so the higher octane gasoline will not keep your fuel system cleaner, and it will not make the engine run any differently than the required octane.

If you have been using 91 octane for the past 10 years with this car, you have been throwing your money away for that extra octane.


Keep in mind that over the years a car may have a carbon build up in the engine, creating a higher than designed compression and there for a higher octane requirement. It is also true that some higher octane fuels include additional fuel additives, like fuel cleaners. The additional compression calls for higher octane and the additional additives can, make a difference. While most cars will not benefit from either the higher octane or additional additives, some cars will. They are the exception not the rule. Of course there is the octane placebo effect. (:slight_smile:


If you don’t need it, you don’t need it. Additional octane will not help an normally operating engine that was not designed for it.

I believe we can trace this back some years to the marketing people in the oil companies. In order to increase profits, they wanted to sell more high octane fuel. So rather than call it high octane fuel they called it Premium. The only thing really premium about it is the price and the profit. Some added a little more additives, but today the government regulates it so all gasoline has sufficient additives for normal engines and additional does no good. People were conditioned to equate high octane with quality, when if fact is has no relation to quality.


Most likely, it requires 87 octane, and as the manual will tell you, there is absolutely no advantage to using gasoline of a higher octane than is recommended.

Nope…for this engine 91 is the recommended octane.


GM recommended premium gas for a Saturn?? Not such an economical car in the long run, I guess.

Also, tvfreakazoid’s post (the one where he hijacked this thead) seems to imply that this car calls for 87 octane, and he is wondering if 91 octane would be better for his engine in some way.


Sorry VDC…My mistake…I thought you were replying to the OP who had the FJ…NOT the Saturn.

I have no idea what the octane requirement is for a Saturn. Probably is 89.


No problem. When someone decides to hijack a thread, as tvfreakazoid did, it can become VERY confusing.