An engine is always a motor, but a motor isn't always an engine. I've seen the argument made for "rocket engine" vs. "rocket motor". I can't believe this argument is still going on. Drop it, make a new thread about it.

Someone do some sort of test that shows what the benefits of 89/91 are over 87. Maybe we, the American moronic public, don't see the worth in 20 cents more per gallon because we don't see or know what the benefits are, if any.

 

Word. Someone with a scan gauge should perform the test. They could tell right away. I do not have a scan gauge.

 

Nope an engine isn't always a motor. Like I posted about an internal combustion engine on a test stand with just a flex plate it's just an engine not yet acting as a motor until the power output is used somehow.

 

I recommend the higher octane... I use 91 and I feel and see the big different against 87... It gives you more milages and power. Why don't you guys try it with your self.

As you can see in yours owner's manual... on page "132"




Its really clear that using lower octane can lead to engine damage... Just my 2 cents. Remember Honda made these owner's manual so I listen to the experts.

 

Lower than the recommended octane can result in damage but using at least 87 is just fine. You are reading it wrong it is designed to work on 87.

 

Still waiting for anyone of those that claim to see better eco with greater than 87 Octane gas to post some real test results.

Did myth-busters test this yet hmmmmm

 

I haven't verified this with my Fit yet, but I can verify that a change in octane helped my MPG on my previous car. That is a Saturn L300 (V6). Prior to the change in octane, I was getting 21.5-22 MPG per tank, using 87. I switched to 91, with no change at all in my driving habits, and the MPG changed to a solid 24 (verified over several tank fulls). Since I was getting a 10% increase in MPG for less than a 10% increase in price, I stuck with the 91.

I'm just starting to stabilize my MPG and driving habits in the Fit (42, 44, and 42 on the last three tanks, 2500 total miles on the odometer), so I'm thinking I can start making some other changes and determine if they help or not.

Both the L300 and the Fit have 10:1 compression, so it makes sense they can benefit from higher octane by being able to advance the timing, therefore providing more power from the same amount of gas (or the same amount of power from less gas).

I don't have an SG yet, but I do have a Scantool. I'll hook that up to my laptop and do an A-B-A of ignition advance under various driving conditions for three tanks. I'll record the MPG too, although that data won't be as useful or accurate, since I won't be averaging it over several tank fulls.

--Barry, '08 FS MT BBP

 

Is their a minimum age requirement to post? If not, could it be at least 12?

 

The result is different for me. My average on 87 is 31-32. I tried 89, the mileage drop to 29.

 

That is really too small of a window to make a conclusion. In fact, that is very consistent unless you are living in a vacuum!

 

If the engine isn't amapped to take advantage of the higher ctane you are wasting money.
87 will burn faster anyway, as the highwe octane fuels resist detonation and flame propagation.
This has been gone over so many times.............
But it's still amusing to watch the fast and furious crowd buying octane boost thinking it will give their civics more bang.

 

You might want to consider reading up on how the Vtec on the Fit works. Octane 89 won't burn cleaner than octane 87 because when Vtec kicks in, it'll swirl the air/fuel mixture causing it to even out. One of the reasons why higher octane was used in the past was to give some time for the gas mixture to even out by delaying the detonation. Also, as long as the timing on the fit is configured for octane 87, there should be no problem with knocking or pinging unless something is wrong with the car's timing setup.