lenny82, don't I know it.

I live in a suburb of Madison, and if I clear the tree-line I can see our Capitol building. One night I filled up Spinner and went to see if some local intersection work had been completed in Cottage Grove--that's another little burg only one off ramp away.

As I cruised through that intersection--and never out of sight of the Capitol Building--my fuel warning light went on during this short loop.

So I'm only out of the Madison city limits by a handful of miles, cruising through Podunk before dusk, and many of the gas stations are already closed or non-existent. I took a gamble.

By continuing away from Madison I knew I would cross a highway that led to my Harley dealer. Next to that dealership is our tavern and a filling station. If the station was open, and if I could make it, no prob. But if I failed at least I was running out near bikers or a mechanic with access to gasoline. Fortunately the gamble paid off and the station was open.

And as much as I love to pile the miles on Spinner, this constant warning light problem is beginning to wear on me. I'm sure a Nightster would have been just as good, but Spinner is more like the Sportsters of my youth. I have a sport rack on the back, maybe a spare tank is good idea after all.

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Well, I have enough miles bike this year to formulate a guestimate on what I'm getting for miles. Of course, this is for highway miles, because I hate riding in the city.

I have noticed that my mileage is almost identical to the price of fuel when we were paying 4.14 per gallon. That is, when I rode 23 miles, I paid 2.30 to replenish. For some odd reason, the farther I ride the better the equation in my favor. For example, on one occasion I rode 55 miles and paid only about 4.75 to refill. (?)

Last night gas dropped to 3.89 for a gallon of premium. I went for a spin, and my tab came to 2.02 for the jaunt.

Now granted, there's nothing I can do about this anyway. But I felt I had to provide Lenny with some hard data. He raised some valid issues for all of us as we get clobbered at the pump.

Oh, as a benefit, I have more power and a quicker response than a man should have. This is clearly the most powerful Sportster I have driven. Coupled with maneuverving ability I have never experienced, this is one little spitfire. I could tell you about a little stunt I pulled last night on the slab between two over-the-road trucks and a slow moving idiot, but then I'd have to kill you...

Hey Tourist,
how much gas, in gallons, do you use up to travel in miles the distance between fills?
Miles Per Gallon = mpg = the amount of gas/fuel in gallons (128 fluid ounces), to travel a distance in miles.
So in one concise number, probably with a fraction could you tell us your MPG on spinner?
I get 32-38 city and 46-60 highway, the 60 was the best I ever did but I was drafting semi's to do it, with my 80 ci 1994 roadking, running premium gas.

Ahhh, that's where I'm going to need you guys. I'm trying to eliminate variables, and I'm having a real problem.

For example, as you know, I carry Harley's "cuff" product. It slips over the gas nozzle and allows you to fill the tank right up to the cap floor. In a small peanut tank, that's a big deal. With my motor still tight last season, I added over 7 miles just using the cuff.

Now, I don't use the cuff for cruising around town, I just fill the tank until the pump clicks off and I pay the tab. Depending on how far I shove in the nozzle (and I wish I had a nickel from every woman who has moaned that very observation) my trip odometer varies up to 10 miles.

And besides last year's wildly fluctuating prices, there is my driving habits. I might deliver a knife or go to the gym--all on 45 MPH highways. Then I might get a wild hair and speed around on the slab to get home. And I live in an area called the "the split." It's a maze of city streets, Class A highways and three Interstates that circle my home. You need to use all of them to go anywhere.

I had thought of this. First, I drive directly to the slab and find a gas station right on an off ramp. I fill with the cuff and re-set my trip odometer. The I drive dead-flat at 65 MPH to the farthest off-ramp that lets me deplete enough of my tank to circle back to the original gas station and refill again with the cuff from the same pump at the same price. Then I send a PM to Lenny with my data to crunch the numbers...

Yikes, I'm a biker. I didn't like math as a kid. I'm just trying to find the tipping point to see if replacing my tank with a Nightster's is worth the cost. No biggee, just getting on and off repeatedly is a pain. That is, unless I had a lot of latte' with my newspaper. Then getting off is a really good idea...

But you sound like a contemporary of my age, or close enough. We get a "Spidie sense" for how the beast gulps fuel. Seat of my pants, I think Spinner gets 47 MPG. My warning light clicks on about +/-57 miles. Assuming a peanut can get about 80 miles per tank, and EFI bikes have no reserve, and there's always some error, my guess is that by 65 miles on the odometer I'd better be rolling into a gas station. That gives me a 5 mile-error-margin. I haven't had to push her home yet.

However, I'm not good at this type of thing, hence the thread. Am I honestly missing something?

MPG formula
miles / gallons = MPG

here's an example
you drove 60 miles
you put 1.5 gallons of fuel in the tank to replace a full one.

60 miles / 1.5 gallons = 40 mpg....

divide 60 by 1.5 use a calculator if you need and you get 40

So for 50 mpg you'd go about 75 miles on the same amount of fuel.

Thanks for the info.

The variable aspect bothers me--but maybe for no reason. But let me explain.

As I stated, there are numerous types of roads and highways surrounding my home. I'll be banging the transmission constantly. I don't know if it's just the sound of the new Screaming Beagle pipes or not, but there is tremendous difference in the revs at speed. Considering that I am in differing gear ratios I *assume* that I am burning fuel at wildly different rates.

Like I said, I assume. To me, a Sportster is a 'little bike.' Even shifting around within the higher ratios might not be effecting fuel consumption at all. I do not know.

What I do know is that at 50 to 57 miles, my fuel warning light goes on. On average I am eight to ten miles away from a ramp or a gas station. Overall, my concern is EFI and no reserve. When the motor stops, it stops.

Okay, guys, here's some hard data!

I had 1.2 miles on Spinner when I left about one hour ago. My trip odometer read 24.2 miles when I filled on my way back. Premium is 3.94 per gallon, and my tab was 3.03 right to the cap tunnel.

Now granted, another bike and I rode rather "spiritedly" on the way back. Hard acceleration off the ramp and stretches of 75 to 80 MPH on the slab. We might have to figure that.

However, based on this data, can you guys compute my mileage? Here's what I got:

At that price, I used .769 gallon(s). My total mileage to fill is 24.2

24.2 divided by .769 equals 31.46 MPG.

That's seems mighty low.

your math is correct
either - your throttle hand is just a little heavier than you'll admit or your not getting really good mileage for a bike that size... "mighty low"
Just rule of thumb... I'd guess-timate very high 30's into the 40's for a bike like that...
Maybe that big front tire is eating up the gas, JK
but have you checked tire pressure? 5+% right there.
now that you know your math is correct do some tests, just keep the data and ride conditions together to get your profile. I'll bet if you kept it easy and did a "just slab" ride you'd be in the high 40's at least.

Tires are fine--I have an air compressor in my garage. Under normal circumstances, 57 miles to the odometer takes a little more than a gallon to fill 'er up.

Ahhh, I was going a tad 'quick' in my jaunt, perhaps I made a bit light of the conditions and my behavior. Lots of third and fourth gear thrashing, and a few bonzai runs to jet around traffic.

Just good, clean American fun...

(Here's my compressor.)

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Yikes, it sure makes a difference on a Sportster on whether you're crankin' it or not. For example:

Today I drove like my sainted Aunt Clara. I went 44.2 miles, and bought 4.04 dollars of fuel at 4.39 a gallon out on the slab. (And they put away my cousins for racketeering, but I digress). I also topped off at my neighborhood station, and they only charged me 3.94 for premium.

That computes to .92 of a gallon.

That means that 44.2 miles divided by .92 gallon(s) equals 48.04 miles to the gallon. (My seat of the pants feeling was 47 MPG.)

Now I did go around a few geezers on the slab at 70 to 80 MPH, but just to clear them, not a bonzai run. So it looks like the go-fast mods I made to Spinner actually make her go fast, but if I keep my hands off of the throttle I can get good gas mileage, as well.