Modern Vespa

I did do a search, and I hope I didn't miss something....

I'm discovering with my GTS 250 Super that the mpg every fill fluctuates as follows:

mpg //// trip miles //// gallons to fill

93 //// 99.0 //// 1.064
70.1 //// 41.1 //// 0.586
94.1 //// 119.7 //// 1.272
69.8 //// 125.5 //// 1.797 (reserve light on at 121 miles)
102.9 //// 115.6 //// 1.123

If I just take the total miles accumulated so far (except prior to first fill which was dealer putting gas in) and divide by total gallons put in on all the trips it comes out to like 86mpg or so.

Filled at same gas station, always one of two pumps, but not in exact alternation from pump 1/ pump 2/ pump 1 etc. Filled always with handle over engine/pet carrier area. I try to hold the nozzle on slowly, well below the first notch and stop when nozzle shuts off. I try to insert nozzle fully.

I also have a powerful LED flashlight which I shine in the tank to check level. It usually is about half an inch below the bottom of the neck ring when done. This does vary a tiny bit.

The mpg goes from unrealistic (93mpgish) to realistic (70mpg) and back in a regular pattern. This is about a difference of roughly 0.4 gallons or so each fill.

It's also interesting that the one time the reserve light came on, it only needed about 1.8 gallons to fill. Although this is spiting distance from 2.0 gallons...

It has just reached end of break-in. I probably have about 15% of the miles overall > 50mph, though can't say if one tank saw more throttle than another.

Can the nozzle really be shutting off with a variation of almost half a gallon to cause the pattern of 90-70-90-70 mpg? Is my trip odomer off? Or just my math?

Sorry for all the numbers, verbiage, hope you folks can wade through to the question I'm asking...

I think relying on the auto hose shutoff is your main problem on accurate MPG tracking. You need to fill the tank manually and eyeball the level to as close to the same fill level ,each time, as possible. On my ET4 I aim for the bottom of the unleaded restricter tube, on my PX150 IT'S JUST my best guess. To reduce the fill-up variation error average out 6 months or a year. There will be be some variation from tank to tank caused by using more throttle, riding hills, driving on routes with higher posted speeds, carrying a passenger, etc. Happy riding!!

Yeah! I just fill up my tank and zero my trip odometer. when I Fill up again take the gallons that it requires to fill up again with the miles on my trip odometer. I am consistently in the seventies.

Of course i dont use a flashlight to fill. I just pull the trigger till it goes click.

Anything more is borderline OCD. http://www.concernedcounseling.com/Communities/Ocd/sandra/signs_symptoms.htm

Same here. The dealer recommended only filling till that first click. I do so knowing that the fuel in the tank may not be at the exact spot each time, but it always registers full. My mileage has fluctuated from about 59mpg on the first tank to 79 a few tanks later when I had near 600 miles on the scoot. I suspect it's a combination of being a new rider, breaking it in, and the routes I'm taking (it's very hilly around here, with steep climbs). I'm leaning more to the 65mpg range these days.

I had been filling mine 1st gallon in fast then 1/2 gallon in slow, then inch it towards 1.90 gallons. mine is always wanting a fill up at this point, hell i thought i should go another few 20 or so miles. i have averaged 65mpg on my 250 .

Don't mean to complicate your calculations but according to the forum, most speedometers on Vespas seem to display inaccurate readings as compared to GPS(widely considered accurate). A search will likely yield an
average deviation which can be used to more closely reflect your real MPG. Uh...I'm just say'in...

You know I actually think my Vespa is getting like 800 mpg. Yep the GPS was right. Jk'ing!!!!

On the car/bike moiunted GPS units do you have to get them accurized or anything? I know that some are only close, approximate. My RADAR in my patrol unit is aupposed to be accurate within +/- .04 mph. I want to RADAR mine and my wife's scoot when we get some free time together.

the gas station is ripping you off by pump selling you mare gallons than actually pumping. that is why you mpg is so good. the only way to know your getting 1 gallon of gas is to fill a gas container the fill the scoot.

102mpg is far enough outside the norm that I have to conclude that your calculations are off by a pretty wide margin. The GTS should get around 70mpg in-town, with some variance for riding style. But not 32mpg variance.

unless somebody is playing a joke on you and putting gas in your scoot when you are not looking. classic old joke. but these days too expensive to do.

Yes, and also when the total miles on scoot and total gallons I put in are calculated, it's more like 86 mpg. This is with the first fill/miles put on by the dealer's gas removed from the calculation.

The speedo is about 5 mph optomistic. Below 30mph it follows the 10% optomistic rule. I haven't checked odometer against GPS, just speed.

But from my searches, the actual odometer is supposed to be more accurate on most motorcycles. The speedo is more likely to be 10% optimistic.

This leaves me with the question of whether my trip/total odometer is malfunctioning or not. First it counts too fast. Then too slow?

You see my point. First service is tomorrow with my dealer, wanted to get some ideas before I went in.

Maybe just sell it it sounds totalled to me.

The odometer is pretty accurate. Also, 86mpg as an overall average still sounds high. Not impossible, but high. I'd be more inclined to believe you're not filling up consistently and/or miscalculating than to believe your tripmeter isn't working.

Jess I like that map you added to your signature where could a person get this from?

Just like this.

I fill up on the same pump and mostly ride to and from work. My MPG has been extremely consistent ever since I bought the Vespa. It has ranged from 3,3 to 3,7 liter / 100 km. (6000 km ridden in a little over a year since new). Currently it normally uses 3,4 or 3,5 liter / 100 km.

Here you go: http://www.epgsoft.com/VisitedStatesMap/

I do think it's important to have an accurate trip/total odo reading in many cases. My total odo now reads 750 miles going into the shop for first service.

But what if there is something weird going on and I only have 400 miles on bike...?

Granted this is a FAR out and very unlikely case but it illustrates my point. Trip/total miles help in a lot of situations...when to fill tank, how far is it to a friends house, etc.
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In an attempt to treat this with a little more perspective, I'll now relate the thread on the StellaSpeed Forum a year or so ago about odometers and California.

It seems you can (or could) bring a used Stella into California if it has >7500 miles on it. I think that's the right number. So someone took a power drill, connected it to his speedo cable and ran the mileage up. Worked well too. Took snaps of the resulting dash.

I haven't seen anyone with a cordless drill lurking around, but I'm starting to wonder...

Mine has varied from 61 to 140 mpg (80.7 +/- 18.47 mpg or 34.31+/- 7.85 kpl ) using gas pump and odometer numbers. I couldn't really be bothered to find out where the variation occurred. I suspect it's in the pump delivery, but I'm not interested in documenting improper gas pump calibration as a hobby. Scooting is enough of one for me.


Regards
Harvey

Drag and drop. Mostly, you just steal it.

I used to be a mechanical engineer with part of my responsibility running tests and doing a lot of statistical parts fitting stuff. Been away from it for 15 years or more, thank goodness, but it still comes back to grab me now and then.

I also think it's probably pump shutoff variation, but it still doesn't explain the overall 86 mpg during break-in, esp when I weigh currently 205 pounds and altitude is 5000 feet. Unless pump readout is too high.

Interestingly, I was getting over 80 MPG for the first few tanks, but on the last two, the Fly 150 appears to be getting only 46 MPG.

My first two fill-ups were 66.65 and 66.78 mpg. While I generally go to the same station and the same pump (when the warning light comes on), I have noticed more variation on highway trips or small volume topping up.

Regards
Harvey

It seems to me that part of the issue may just be there is too small of a sample set of numbers which increases the chance for a larger margin of error. I would be willing to bet that after the OP has put in 15-20 tanks of gas and averages the gallons of gas with the total mileage, you will find that your mileage falls within the norms that others here have posted.

Just a guess...

Desi B.

Why would someone want to steal a map of someone else's visited states? There's a website that will generate the map for you based on your own personal list of visited states. I hardly see the point of stealing someone else's.