Gas Question: Premium vs. 100% Regular

Joined
Mar 11, 2010
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Colorado
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'08 ST1300
I run midgrade; & to minimize deposits I try to buy from these retailers-- see www.toptiergas.com ; or every now and then I might splurge and put some BG44K to clean up the engine top end. I think you can run 10% ethanol in your gas, no higher, without ill effect; but your all correct; don't let that stuff sit for more than 30-45 days unless you use a gas stabilizer e.g. stabil
 

Toaksy

Tim Oaks
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I try to run premium as much as I can but you also have to think about how much premium the station goes through some places it’s better to go with a mid grade. I have gotten premium in some places that I could tell a marked drop in how the bike ran. In some off the beaten path places the premium is on the old side. I try to take it into consideration when I get gas. But mostly I don't worry about it and just ride.
 
Joined
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The Wilds of Western Wisconsin
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I generally run the fuel that the manufacture specs under the theory that they likely know more about the needs of their engine than I do. I have noticed tho that premium tends to be non-oxygenated more often than any other grade, particularly in boat country. Since figuring that out I now run premium in everything, even the KLR. I seriouly doubt that the grade matters in most situations but I'm pretty sure that ethanol in a more demanding applications (like a motorcycle or boat engines) does.
 
Joined
Jun 19, 2011
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Many, La
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07 ST1300A
What about octane additives they sell at part stores? Like most of you guys, our local bulk plant recently started selling pure gas, but only in 87 octane. I don't mind spending alittle more for super unleaded, but why pay more for less fuel mileage with the E-10.
 
Joined
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Halifax, PA
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I've been running 89 in my 1300 for awhile now (with ethanol, can't get ANYTHING else:() It's been 10 cents a gallon more than 87 forever. Last night I pull into a Sunoco and the 89 is 20 cents more than the 87,never mind the premium at 50 cents higher.

Gas prices keep getting worse.

As far as octane boost goes read the can and decide. Most state will raise the octane "X" amount of points. That's not 89 to 90 for one point that's 89 to 89.1.
 

T_C

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Just a quick mention... some folks I have talked to in the past about these fuel related things. Just an FYI. There is no such thing as mid-grade gas at a station that has low, med and high octane. The medium octane is really just a 50/50 blend of the low and high.
T
 
Joined
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Fort Myers, Fl
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3774
Around SW Florida, 'recreational gas' is 90 octane. I use it in everything (boat, MC's, lawnmower, etc.)but the cars. Seems to work great. I use the 'puregas' site. I just take a bunch of 5 gal cans and fill up.
 

KAJ

Joined
Jun 21, 2005
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6
Location
Suwanee GA
Premium with ethanol OR unleaded without ethanol?

Which is better to use and why?

I should have specified "regular" unleaded with ethanol.
 

CYYJ

Michael
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Concerning the octane rating of fuel that we use in Electronic Fuel Injection (EFI) motorcycles that have a computerized engine control, I think we can take some guidance from the automobile manufacturers.

I have two Volkswagens. The owner's manual for the one that has a 12 cylinder, 450 HP engine recommends premium grade fuel, but notes that the car will perform satisfactorily with regular grade fuel. The owner manual notes that the engine won't make full rated horsepower using regular grade. The owner's manual for the other one, which has a turbocharged 4 cylinder engine, mandates premium fuel. The owner manual notes that regular grade fuel can be used in an emergency when premium fuel is not available.

I'm quite familiar with the 12 cylinder engine design and engine control system. The engine has 4 knock sensors, and if knock is detected, timing is changed until the knock stops. My guess is that if regular fuel is put in the car, it just adjusts the timing accordingly, hence the reduction in horsepower available.

Given that Honda is recommending, rather than mandating, premium fuel for our motos, I think that implies that no harm will be done if regular grade fuel is used. I suspect that engine power output is diminished when regular fuel is used.

Where I live (Canada), the price difference between regular and premium is about 6%. Although I like to save money as much as anyone else, I think it is incongruous to make a discretionary purchase such as a sport-touring motorcycle or a 12 cylinder car, then give up the performance we paid tens of thousands of dollars to get in order to save $2 on a fill-up.

I could understand the desire to save a few cents on every fill-up if this was a discussion forum for Yugo cars, or cheap Chinese 150 cc bikes, but I can't see the point of trading off performance for such a small dollar saving in a forum where the price of admission is a $17,000 moto.

As for that ethanol crap... I read an article in the WSJ last week that stated that the USA was soon going to be second only to Saudi Arabia in domestic oil production, this a result of all the shale oil getting pumped out of the Bakken formation. Why the heck is the government in the USA still permitting gasoline to be adulterated with ethanol? The days of Arab oil embargoes are long gone. Shouldn't that ethanol crap be outlawed now?

Michael
 

ST1100Y

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Shouldn't that ethanol crap be outlawed now?
It only serves the stats, enabling to claim lowering the CO? output (based on ethanol being of "natural" origin...)
And while we have to take that, ships still run on residual oil (AKA bunker oil)... go figure...
 
Joined
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I recently looked at the owner's manual for the new 2015 Indians online, and found the following fuel recommendation interesting, FWIW:

Specifications
Fuel Recommendation
For best performance, use only unleaded gasoline with a 91
pump octane minimum (R+M/2 Method). DO NOT USE E-85
GASOLINE OR GASOLINE CONTAINING METHANOL. Using
E85 or gasoline/methanol blends can result in poor starting
and driveability, engine damage and damage to critical fuel
system components.

? Gasoline containing up to 15% Ethanol can be used.
? Gasoline containing up to 15% Methyl Tertiary Butyl Ether (MTBE)
can be used.
In the event that the recommended premium unleaded
gasoline is not available and low octane fuel must be used,
fill the fuel tank only partially with unleaded regular
gasoline, then fill the tank fully with premium unleaded
gasoline as soon as possible.


What I found interesting was the fact that Indian apparently had the foresight to be ready for what may be inevitable and designed their engines and fuel systems accordingly - E15. I haven't looked closely at any other new motorcycle specs or owner's manuals, so don't know if any of the other new models have this capability or not.
BTW, no I'm not about to defect...
 
Last edited:
Joined
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Unless the guy ahead of you bought premium, I would guess you always start with a hose full of Regular before you get any premium anyway.
 

Kevin_56

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Unless the guy ahead of you bought premium, I would guess you always start with a hose full of Regular before you get any premium anyway.
A 10 foot long 5/8 inch diameter fuel hose contains .17 gallons of fuel. A 3/4 inch delivery hose would be .41 gallons. Have heard that the unused fuel will return back to the storage tank, I am going to assume not. The amount of remaining fuel is not enough to make much difference.

My bike will knock if filled with several tanks of regular. Not if it is just one tankful. Runs fine on mid grade. I pay the extra if it is reasonably higher for premium. Right now at a station on my way to work, it is $1.00 higher. Another is just $.40 higher. Sure hope these current prices hold for the summer riding season.
 
Joined
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Newport News, VA
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I don't mind the seldom tangle one encounters with the gas pumps having individual hoses for each grade of fuel.
 

dduelin

Tune my heart to sing Thy grace
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I recently calculated that running premium has cost me about $1100 over burning regular grade in my ST. On occasion I've run regular or mid grade but most of the approximately 3,600 gallons has been premium.
 

T_C

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A 10 foot long 5/8 inch diameter fuel hose contains .17 gallons of fuel. A 3/4 inch delivery hose would be .41 gallons. Have heard that the unused fuel will return back to the storage tank, I am going to assume not. The amount of remaining fuel is not enough to make much difference.
I agree not enough to make a difference.

But I calculate .23 gallons in a 10'x.75" (id) hose.
 

Kevin_56

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But I calculate .23 gallons in a 10'x.75" (id) hose.
You are correct on that. Must have entered a bad number. A very small amount if one puts in 6 gallons to fill a tank.

I always like to ask people how many gallons in a cubic foot. When you think of the size of a gallon of milk for a starting point.

Hard to believe it is 7.48.
 
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