What kind of gas do you pump on yours GE´s? How much Octanes does it have?
Here we have the "Super" (95 octanes) and the "Premium" (97 or 100 octanes). MPG may vary?
Honda recommends to use 95´s... but the 100´s is more fun.

 

dont waste your money get regular. these new cars and there
computer systems automatically adjust. so high octane does
nothing.

 

They do adjust..... Ignition timing and fuel ratios change to accommodate fuel octane ratings as low as 87 but no lower...... I can't even use that low an octane rating in my chain saws, weed eaters and lawn mowers and get optimal performance without adjusting the A/F ratio richer to not overheat and seize..... You can use fuel with 87 octane without doing harm but the higher octane fuel really does run better..... Honda and other auto makers would just use static ignition timing and constant A/F ratios other wise..... The owners manual has a minimal octane warning, but there is no maximum octane warning.

 

I am a new Fit owner, so I tend to rely on my dealer until proven wrong. According to the Service Mgr at my local (Los Angeles) dealer, the ignition timing will adjust down, via the anti-knock sensor, but not up. I have an Avalon that gets 10% better mileage using premium rather than regular but do not have enough consistent open road experience to contradict the dealer. I intend to find out when I take a good long road trip.

2010 Fit Sport 5M

 

Thank for the answers.
So, I can put the regular with 93 octanes and there will no problem? The owners manual recomends 95.

 

oh wow i never knew our fit's could use that kind of fuel.. i been filling up with nothing but 87 like a dummy

 

If you are using an octane rating where 87 is the regular, it is just what the engine is designed to use. In some countries regular is a higher number because there is a different formula. I am not a petrocemical engineer but I flew airplanes when the octane ratinge read 80-87 for regular and 100-130 for premium, confusing huh? In the US I believe that the calculation usually results in the listed octane numbers as 87 for regular and 91 up to 95 for super premium. If you live in an area up in higher altitudes you may have gasoline with lower numbers that work just as well but that is a whole different story.

If you want more info, I have inserted a quote from wikipedia.

"Research Octane Number (RON)
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.
Motor Octane Number (MON)

There is another type of octane rating, called Motor Octane Number (MON), or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load as it is done at 900 rpm instead of the 600 rpm of the RON. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally, fuel specifications require both a minimum RON and a minimum MON.
Anti-Knock Index (AKI)

In most countries, including all of those of Australia and Europe the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI). It may also sometimes be called the Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2.
Difference between RON and AKI

Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel. See the table in the following section for a comparison"

 

I would add that you should stick with a tier one brand of fuel too.

 

I strongly agree on sticking with a top gasoline brand for purposes maintaining fuel-cleansing properties. I see that both Shell and Chevron advertise that they double or triple the cleaning agents in the premium brands, so an occasional fill-up with premium is a lot cheaper than a can of fuel additive.

 

I always use 87 octane from 76 or Chevron.

 

I haven't seen those advertisements about more detergent in premiun, however both Chevron and Shell are both Top Tier gasolines Top Tier Gasoline . They certify the quality and detergent level of all their grades.


"1.1 Retail Gasoline Performance Standards. The deposit control performance of unleaded gasoline conforming to section 1 of this document shall be met at the retail level in all grades of gasoline sold by a fuel company in all marketing areas of a selected nation. In addition, conformance to the standards shall mean gasoline sold in the selected nation shall not contain metallic additives, including methylcyclopentadienyl manganese tricarbonyl (MMT)."

 

[quote=spreadhead;799550]I haven't seen those advertisements about more detergent in premiun, however both Chevron and Shell are both Top Tier gasolines Top Tier Gasoline . They certify the quality and detergent level of all their grades.]

You have hit the most important part of what goes on in the combustion chamber that a computer chip can't control ... deposits. Staying with quality gasoline (not E85), and you should be fine.

One word of caution though. If you fill up at high altitude, say Yellowstone National Park, where regular is way below 87 octane, the car's computer will greatly retard your timing. Even so, you can have engine damage if it cannot retard enough or if you drive too long at a lower altitude before getting your average octane in the tank back to 87.

2010 Taffeta White
Fit Sport 5 spd

 

The top tier gasoline spec was interesting, but I was puzzled by this part:

"Contain no less than 48 mg/kg sulfur. At least 60% of the sulfur shall be derived from FCC blend stock."

I had always thought of sulfur as a contaminant, but this is specifying a minimum level. What role does sulfur play in gasoline engine combustion?

 

This article was helpful!

Octane Boosters Testing - Tech Review - European Car Magazine

Yes, your computer adjusts, but lower octane decreases performance.

 

I just checked my user manual last night (page 198, I believe -- it's still out in my car) and it says 87 octane. I have a base fit, but I assume that this is the same for the base and the sport models. So, unless you're driving in a country other than the US where the calculations are different as GW Fit suggests, or perhaps where the vehicle itself is different, perhaps you misread it?

 

Hi,

I'll do my best to answer your question and the one asked previously. A while back all we saw on the pump was RON or Research Octane Number which gave regular a 91-93 and premium 100+. There was another index that rated the anti knock properties differently and much lower and was called MON or Motor Octane Number. Today we use an Anti Knock Index that is an average of the two (R+M/2) that may be called Pump Octane Number.

Don't worry about the number if you are purchasing a decent brand of regular unless, it is in the mountains above 6,000' where I have seen regular at 85 and below or it is called E85, which is not fit for our Fits. If you fill your tank at Yellowstone NP and drive south to the lowlands with 85 or lower in your tank, you will force the Fit's engine computer to severely retard your timing and might cause engine damage if you are pedal to metal going up hills and hear heavy knocking. Solution, fill-up with premium as soon as you get down the hill.

 

Yeah, I drive outside US, I live in Argentina.
Searching for some info about this, I notice that here we use RON index for octanes. Then ours 100 octanes is the same fuel that you have like 95. I gess.

 

I recall that RON 91 was the rating given to regular when RON was the standard that most everyone used. What does your owner's manual list as the fuel requirement? According to the chart on octane conversions 87 pump octane is about equal to 91-92 RON. If you are using anything over that you should be fine unless the ECM (Engine Control Module) in your car has been adjusted to take advantage of the higher octane. Once again I would rely on the book first. If you want a more specific answer, you should contact Honda | Argentina

Taffeta White
2010 Sport, 5 spd

 

I remember when I was looking at acuras, the required fuel was premium. Their mechanic said that you could use regular with no ill effects, but you would lose a little horse power. Now I wonder if that still holds true?

 

It's all how the factory programs the ECM chip. I have an Avalon that the owner's manual says is designed to run on regular but will have better performance on premium. When running regular on the highway I get about 27 and when I run premium for a few tanks (it takes the ECM a while to adjust) I get almost 30. My first few tanks of gas in my new Fit were with Vpower premium and I was getting around 43 on the highway (measured not using the trip computer) but I also kept the speed under 60 and the rev's below 3K. When I get around 10K miles this Summer, I plan on a 5K road trip and plan to use premium one way and regular the other. This is the only way I will be satisfied with the results.