Who's running Regular
Road Warrior
Joined: Oct 2006
Posts: 1,916
Likes: 0
From: San Antonio, Texas
Mine gets premium, don't care about the cost. The difference in price for as little as my ride takes is negligable. It pings under hard acceleration anyway so using regular is just asking for this to get worse.
As Wide Card said, high test burns differently - it actually burns slower, or rather in a more controlled fashion to help prevent detonation. Detonation is two flame fronts colliding, causing the "ping" noise. One front is ignited by your plugs, the other by a hot spot in the combustion chamber.
As Wide Card said, high test burns differently - it actually burns slower, or rather in a more controlled fashion to help prevent detonation. Detonation is two flame fronts colliding, causing the "ping" noise. One front is ignited by your plugs, the other by a hot spot in the combustion chamber.
Road Warrior
Joined: Oct 2006
Posts: 1,916
Likes: 0
From: San Antonio, Texas
Road Warrior
Joined: Sep 2009
Posts: 1,465
Likes: 62
From: Port St. Lucie, FL
This means there are less BTUs/energy in a gallon of Premium gas than in a gallon of Regular gas. Those that claim they get better mileage using Premium when compared to Regular haven't figured other variables to achieve this claim.
Wind direction, road conditions, air temperature, elevation, weather, motorcycle load and even the gear the biker is wearing all comes into play.
The amount of fuel being topped off at the same level is hard to be exact. Outside of a labatory the exact conditions are nearly impossible to achieve.
The laws of physics are in play. You can't get better mileage using less BTUs on the same engine under SAME CONDITIONS unless said engine is one that is HIGH PERFORMANCE that must use high octane in order for it to perform properly. Our HD engines are low tech and low performance.
A Gold Wing engine (GL 1800) has a 9.6-1 compression. Honda recommends Regular gas 86 octane. The HD 96" engine has a 9.1-1 yet Harley recommends Premium gas 91 octane or higher. My 103" Stage lll '09 FXDC has a 10.5-1 compression ratio yet has run fine on Regular gas for over 25K miles.
It's like the Dark Siders thread (using car tire on rear), those that never done it have the loudest voices.
In the end it's your money. I change my engine oil every 5K miles using Walmart brand Dino oil.. Some here feel better about themselves if they change their engine oil every 2-3K miles using synthetic oil.
Tourer
Joined: May 2011
Posts: 266
Likes: 1
From: Boynton Beach, FL
Ordered owners manual for my "new" '07 Fatboy (3,600 miles). When I picked the bike up and asked, I was told it was designed for regular; sounds like the H-D Tech was making up his own rules. What does the owner's manual call for? Like most good advice, I ignored it put mid-grade in it. Didn't seem to affect the 2 hour ride home in torrential rain! Now that's a way to break in a new bike 
Cheers, Kevin.
Cheers, Kevin.
Tourer
Joined: May 2011
Posts: 256
Likes: 0
From: Upstate NY
The difference between 87 and 93 in upstate NY is 30 cents.
So, a typical fill up costs me an extra $1.50 with premium (5 gallons).
Not going to Dunkin Donuts one day during the week and taking my travel mug with me with homebrew makes up the difference.
I'd think about if it were a $1 or $2 more a gallon but not for $1.50 total
So, a typical fill up costs me an extra $1.50 with premium (5 gallons).
Not going to Dunkin Donuts one day during the week and taking my travel mug with me with homebrew makes up the difference.
I'd think about if it were a $1 or $2 more a gallon but not for $1.50 total
Road Warrior
Joined: Jun 2009
Posts: 1,687
Likes: 9
From: SoCal & West TN
I have tried different grades of fuel in almost every Harley I have ever owned.
In my latest '09 Road Glide, I keep extensive records of fuel and economy. After 42,000 miles, here is what I have found.
I found that when running 87 octane, the mileage was 30 MPH. I lost as much as 10 MPG over Premium, the motor runs hot, and I get some pings at hard acceleration. There is a defiant "Top Speed" where I can not go faster with full throttle. At High speed, I can loose as much as 20 MPG.
With 89 octane I got 34 MPG. I lost 4 to 5 MPG over Premium. The heat is higher, and there is still loss of power and top speed.
I use 91 octane here in California. Last year I got 38 MPG around town and 43 MPG going to LV. Back east I can get 93 octane. I have gotten 48 MPG on vacation cross country. In Tennessee I got 51 MPG on one tank that I was trailed by THP for almost 85 miles. I could only ride at the speed limit.
This year I installed the Stage One Kit. The bike gets 43 MPG round town and 48 MPG on the way to Las Vegas. The only time I go under 40 MPH is when I ride 80 plus for the entire tank. I will see how the MPG is with the Stage 1 Kit installed when I get to the better grade of fuel.
I'm not an Engineer and don't have spread sheets. I didn't do any graphs of take readings. Bottom line is I get better mileage and power using the Premium fuel. So it is Premium for me, unless there is no other choice.
Too Much?? 
In my latest '09 Road Glide, I keep extensive records of fuel and economy. After 42,000 miles, here is what I have found.
I found that when running 87 octane, the mileage was 30 MPH. I lost as much as 10 MPG over Premium, the motor runs hot, and I get some pings at hard acceleration. There is a defiant "Top Speed" where I can not go faster with full throttle. At High speed, I can loose as much as 20 MPG.
With 89 octane I got 34 MPG. I lost 4 to 5 MPG over Premium. The heat is higher, and there is still loss of power and top speed.
I use 91 octane here in California. Last year I got 38 MPG around town and 43 MPG going to LV. Back east I can get 93 octane. I have gotten 48 MPG on vacation cross country. In Tennessee I got 51 MPG on one tank that I was trailed by THP for almost 85 miles. I could only ride at the speed limit.
This year I installed the Stage One Kit. The bike gets 43 MPG round town and 48 MPG on the way to Las Vegas. The only time I go under 40 MPH is when I ride 80 plus for the entire tank. I will see how the MPG is with the Stage 1 Kit installed when I get to the better grade of fuel.
I'm not an Engineer and don't have spread sheets. I didn't do any graphs of take readings. Bottom line is I get better mileage and power using the Premium fuel. So it is Premium for me, unless there is no other choice.
Last edited by Ultra89Rider; May 20, 2011 at 01:36 PM.
Road Master
Joined: Nov 2009
Posts: 1,218
Likes: 0
From: Yakima WA
When it gets to the point that I have to worry about two dollars difference on a tank of gas tipping my wagon over I would be inclined to sell my motorcycles. If I can't afford that two bucks I couldn't afford to maintain them... Maybe some folks are just that squeeky when they walk though.
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Road Captain
Joined: Oct 2006
Posts: 559
Likes: 51
From: maine
It makes me laugh when I see all this hand wringing over saving a buck and a half on a $30K scoot by running crap fuel in her.... same reaction I have to tire mileage and "how long can I leave my oil in" threads... LOL
I spend a **** ton of money on my scoots, try to give them the best of everything,..... 'cause I want to, like to, and am able to.. they are my drug....
The "crack *****" runs on 8 buck a gallon 110 octane..... she sure loves her crack...
I spend a **** ton of money on my scoots, try to give them the best of everything,..... 'cause I want to, like to, and am able to.. they are my drug....
The "crack *****" runs on 8 buck a gallon 110 octane..... she sure loves her crack...
Road Warrior
Joined: Sep 2006
Posts: 1,826
Likes: 87
From: Cookson, Ok
Don't try to confuse someone with facts when their mind is made up......I choose to run regular in my old Evos because premium doesn't make any difference in pinging if I lug the motor down. I feel that if premium burns cooler in the chamber, it's not burning all the fuel and leaving carbon deposits behind. I have had plenty of vehicles that required higher octane, but my Harleys don't. It's got nothing to do with saving a buck at the pump.
Last edited by Lakerat; May 20, 2011 at 02:04 PM.