Mileage - Real Life, regular vs. premium
#121
08-15-2010, 09:00 PM
I am back to once again quoting my owners manual that states that fuel with an octane rating of less than 87 will harm your engine and is not to be used.... Nowhere have I seen in print from any Honda literature that the Fit is tuned specifically for the use of 87 octane fuel.... The ECU advances timing to a setting just short of pinging and with regular fuel about 25 degrees , premium fuel shows ignition advance under the same driving conditions 10 degrees higher on average.... Using octane booster I have seen ignition advance as high as 49 degrees dropping to as low as 10 degrees at full boost at 4500 RPM and increasing as the A/F ratio becomes richer as the revs climb...... What this proves is that the ECU is constantly making adjustments to make the absolute best fuel mileage possible for the grade of fuel being used and still maintaining a margin of safety too prevent damage being done to the engine.... If there is a problem where the ignition advance remains at a higher level than is safe for low octane fuel there is going to be a costly problem in time where this wouldn't be the case if higher octane fuel is being used.
you're using an aftermarket tune on a GD with bolt-on supercharging.
For the rest of us, regular does just as well.
There is no literature suggesting the Honda L15A (or any economy car) gets better mileage or more power from premium fuel. Quite the opposite in fact.
#122
08-15-2010, 09:26 PM
My car was driven with just an axle back pipe and short ram intake almost 3 years and I almost always used premium....I drive in a rural area with well maintained roads and highways and have driven my Fit pretty fast since day one.... It isn't uncommon to drive 85 and 90 MPH for 45 minutes or longer when I have to be somewhere and it is pretty common for most people in this area for most people to do the same... Even pushing it at these speeds I would average between 37.5 and 40 MPG.... I have noticed over the years that I have either been lurking or posting that there are two problems that seem common to cars that run on regular fuel. One is oil blowing back into their intakes and the other is coil failure..... I have tried to bring this up when there are threads on these issues but it is hard to get any response as to the fuel preferences of those that have experienced these problems so I had to see which way they leaned on threads like this one to come to the conclusion that I did... My engine is tuned differently but the ECU and related sensors still work the same way as they work in all Fit engines.
#123
08-15-2010, 09:54 PM
As far as the Fit's ecu advancing spark timing when higher octane fuel is used, it's possible. I haven't read anything to indicate that this occurs in Fits other than your anecdotal evidence. In the Fit's case, this would promote efficient burning of premium to avoid power and efficiency loss due to premium's different burning characteristics. Kudos to Honda if this is what they have done. I recall a post Mahout though, stating he saw no meaningful difference in timing advance on Fits running premium vs. regular.
If true, this doesn't mean there is any advantage to burning premium, only that there is no disadvantage (in terms of efficiency). In terms of cost I think the disadvantage is obvious.
I'm aware of the advantages of burning premium fuel in a car designed for it. I have one. But it's not the Fit.
If true, this doesn't mean there is any advantage to burning premium, only that there is no disadvantage (in terms of efficiency). In terms of cost I think the disadvantage is obvious.
I'm aware of the advantages of burning premium fuel in a car designed for it. I have one. But it's not the Fit.
#124
08-15-2010, 10:41 PM
I recall Mahout saying theres 3-4 percent more energy in premium, the problem is some people wont notice anything under 5 percent but that dont mean there is no advantage. I put out info on how a ecu works and am sorry that some people dont understand. The owners manual said 95 ron so he uses 97. In the USA Honda says it can run on regular, so its a business decision to write it that way in the owner manual. If you said to use mid grade I would be Ok with that. But premium gas is still a better deal. If you drive fast or lot of highway driving passing cars, you better use premium. Not all premium is the same, Just as some of you put fuel injection cleaner in, no one says thats a waste of money but I thought the minimum requirements of additives is good enough, so why would you say running premium is bad when its higher than the minimum octane. It sounds like a double standard. Also sounds that top tier gas is a rip off too.
#125
08-15-2010, 10:48 PM
I recall Mahout saying theres 3-4 percent more energy in premium, the problem is some people wont notice anything under 5 percent but that dont mean there is no advantage. I put out info on how a ecu works and am sorry that some people dont understand. The owners manual said 95 ron so he uses 97. In the USA Honda says it can run on regular, so its a business decision to write it that way in the owner manual. If you said to use mid grade I would be Ok with that. But premium gas is still a better deal. If you drive fast or lot of highway driving passing cars, you better use premium. Not all premium is the same, Just as some of you put fuel injection cleaner in, no one says thats a waste of money but I thought the minimum requirements of additives is good enough, so why would you say running premium is bad when its higher than the minimum octane. It sounds like a double standard. Also sounds that top tier gas is a rip off too.
Your memory is faulty. Along with your logic.
Your writer in Malaysia uses 97 RON because the next lower grade is 91. Honda in Asia requires 92RON minimum (not the 95 your article states). 92RON is about equal to 87 octane here (using the R+M/2 method).
This is from a Honda site in Singapore.
The same honda site makes no claim that performance differs according to the blend of gasoline used.
#126
08-15-2010, 11:10 PM
You went back to far https://www.fitfreak.net/forums/1st-...tml#post854992. Thanks for making my point 1.3,1.5 can use 92 ron,95 ron and 98 ron for impressive fuel compatibility.
#127
08-15-2010, 11:26 PM
As far as "Top Tier" gas ratings. That web site smells...fishy. There is no "about us" or anything lending it any kind of legitimacy. After googling it sometime back and doing whois queries it turns out this is a marketing campaign devised by Quick Trip. Google the phone number in tulsa for that link. oh hell here it is. That said, I have no problem buying gasoline from Shell, a nice Dutch company that doesn't foul our beaches (yet) as long as they charge the same price per gallon of regular as other stations in the area.
#128
08-15-2010, 11:37 PM
You went back to far https://www.fitfreak.net/forums/1st-...tml#post854992. Thanks for making my point 1.3,1.5 can use 92 ron,95 ron and 98 ron for impressive fuel compatibility.
92 RON is equivalent to 87 octane in this country (using the R+M/2) method.
What is your point? Nothing in the article you posted or on any Honda website, or any article about Honda written by a reputable magazine states the Fit (or any other economy car) gets better mileage/more power by using premium fuel when it's not required/recommended.
As far as Mahout stating that premium might gain 1 mpg, that's not really meaningful. It might not. In any case, since I want to use his statement that there is no meaningful difference in ignition timing resulting from the use of premium I'll allow it.
Did you read the rest of his statement?
Premium gas might get 1 mpg better, or 3% better mpg, maybe, because it does have more btu per pound as a result of the components, mostly toluene, that increases octane, but the cost is generall about 8% more so you lose money. The engine compression is generally the most important spec that calls for higher octane (premium gas) but its not the only one.
The Fits we know all use regular gas except at the track with no problem.
The Fits we know all use regular gas except at the track with no problem.
#129
08-15-2010, 11:45 PM
there is no issue from running higher then 87 octane in the fit.
there is a problem if your car requires premium and you use 87, you won't notice it right away, but you will have carbon deposits and sensors become dirty. THis is the detune on the ECM!
But your Honda fit will definitey increase your MPG on Shell V-Power fuel. compared to regular 87 or even costco premium fuel. I found the Shell V-power gas to be the best. for all you naysayers, I suggest you try a tank of Shell V-Power and report your findings.
How do i Know this? I own a 2002 Acura MDX and run 87 octane and had this problem, i fixed the problem myself was a mess to clean up the intake, I still run 87 octane, just use techron or seafoam a few times a yr.
I use Mobil 1 full synthetic in all my vehicles, can't beat $21 for a 4.73 Liter jug at walmart 5w20.
there is a problem if your car requires premium and you use 87, you won't notice it right away, but you will have carbon deposits and sensors become dirty. THis is the detune on the ECM!
But your Honda fit will definitey increase your MPG on Shell V-Power fuel. compared to regular 87 or even costco premium fuel. I found the Shell V-power gas to be the best. for all you naysayers, I suggest you try a tank of Shell V-Power and report your findings.
How do i Know this? I own a 2002 Acura MDX and run 87 octane and had this problem, i fixed the problem myself was a mess to clean up the intake, I still run 87 octane, just use techron or seafoam a few times a yr.
I use Mobil 1 full synthetic in all my vehicles, can't beat $21 for a 4.73 Liter jug at walmart 5w20.
#130
08-15-2010, 11:56 PM
You went back to far https://www.fitfreak.net/forums/1st-...tml#post854992. Thanks for making my point 1.3,1.5 can use 92 ron,95 ron and 98 ron for impressive fuel compatibility.
The ECU is not concerned with octane' it has no idea.
it only concerns itself wiyth delivering the injection period that matches the ECU map of loasd vs rpm and temperature. Octane's only function is preventing preignition which is a function of compression ratio primarily.
There is a small but definite affect from the combustion chamber design.
it only concerns itself wiyth delivering the injection period that matches the ECU map of loasd vs rpm and temperature. Octane's only function is preventing preignition which is a function of compression ratio primarily.
There is a small but definite affect from the combustion chamber design.
#131
08-16-2010, 04:24 AM
I hurd you can get a special air pump attachment gas cap. U fill with 91 octane, and u attach a bicycl pump and blow it up a few pushes. That makes it high compression, and you get extra power, so you can smoke Mustangs and stuff.
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