Modern Vespa

I posted recently on another thread that we thought my wife's 500 had lost some MPG. That was actually true, she dropped from a high of 71 to 68.5.
So I am not complaining!! Mine is also averaging about that. Sweet!!
But, I don't think anyone else gets that much as I recall, and I wonder why?
Some have said its the mountains here, but then why doesn't our cars get more milage than the average as well?
Is anyone out there getting this much mileage but us??
If not, I have no explanation for it.

Perhaps less urban riding than most, perhaps you are both conservative with your right-hand 'switches'.

However I never get that mileage even with Imperial gallons when riding 'hypermileage'. Altitude will certainly help as the ECU adjusts for it.

You can count on me to zip away from stoplights, at least if I am first in line.
We rarely go more than 75mph. Most riding is heading out of town.
I don't believe I could misbehave enough to get 45, like some folks seem to do.

I would be glad to get 45.

Boutique blends of gasoline have a great effect on mileage. The more oxygenators the less MPG. Ethanol is a common one. It alone is 20% less efficient. Depending where you live there may be many boutique blends in play. California for instance has some 50 different blends in play throughout the state. When I lived there it was common practice to fill up before crossing the state line on the way home. You'll get that last tank of better mileage.

I also suspect altitude may play a roll but have less experience with that because my altitude varies little in Missouri. I do notice the differences in gasoline blends and grades though.

I find here that BP/Amoco premium (93) gives me 5-8 more MPG than the 91 octane every other station sells.

Your mileage is amazing though!

Surely something must be wrong, mechanically, if you don't even get 45? I have gotten as low as 55, but as it breaks in, it seems it has gone up. I am guessing we are, for whatever the reason, on the high end, and you must be on the low side. There must then be an average, say 60 (?), that most people get, and that everyone should be able to get if things are running correctly....it seems unjust for us to get 68 and for you to only get...40??
Thats just not right.

McHarris, ethanol is in all the gas here (Denver struggles with its air quality)
and the highest octane is usually 91, and thats what I use. Normally just a nondescript grocery store brand.
Its a curious phenomenon.
Like I said, our cars mileages are very typical for their makes. Maybe the Mp3s just like the rarified air here, one mile above sea level.

Surely something is tuned very sweet for your driving conditions. We now have a 10% ethanol mandate in Missouri. We also have a huge number of E85 stops but that's for other vehicles, not the MP3.

My wife works for a local farmers gas/oil co-op. They operate a local brand throughout the state. I was brand loyal and their top grade was 91 octane. I stumbled on a BP in town one day that had 93 octane and independent hoses per grade. All the other brands share a hose for all the grades in the pump. I always figured the a big portion of a two gallon fill was the low grade still in the hose from the last customer. I got way better mileage so that is what I use now.

I wish I had your scenery though! Colorado is beautiful.

From the time I got it I kept track on a tank by tank basis and it varied a little and I thought with such a small tank if I failed to fill it to same level each time the results would be off by a much more noticeable amount than if it had a large tank like a car. I filled it five times keeping the receipts and divided the total miles by total gallons and got 39.something MPG. I have somewhere around 1200 miles on it and it still stumbles and farts sometimes on deceleration which I thought was supposed to go away as it broke in.

I'm at 980 miles on my 400, and the BEST I've seen is 46 mpg.....I'd be delighted with 55mpg. I guess I need to slow down, and roll-it-on more gradually.

Nope, not gonna do it!

I've been careful to fill my 400 to the brim for consistency and my average has been about 60 MPH - and I'm still on breakin.

I think you are forgetting several things.

Fuel economy depends primarily on:

1) Speed - 80%

2) Weight - 10%

3) Wind - 10%

Unless you quote the speeds at which you achieve 68 to 71 mpg the figures are not all that meaningful.

If you drive primarily at 55 to 60 mph then those figures are understandable.

If you drive consistently at 75 mph those figures might be exceptional.

Cheers

Trevor G

No way Jose (I mean Trevor),
I am over 250lbs (17 stone), and I drive like a girl (a big one), so my equation would be 10X80X10, and instead of wind,
don't you mean inertia as to refer to an object's "amount of resistance to change in velocity" (which is quantified by its mass), and sometimes its momentum,
depending on context (e.g. "this object has a lot of inertia"), as described by Newton in Newton's First Law of Motion which, expressed simply, says:
"An object that is not subject to any outside forces moves at a constant velocity, covering equal distances in equal times along a straight-line path."

Cheers 8)

Edit: removed fat

Did you mean 60 MPG?

Well, I've got news for you.

I wasn't sure what you meant, so I will explain myself a little better.

2) Unless you have an enormously large body which over-drapes your MP3 by 2:1, your weight will only have a moderate effect on your fuel consumption. I would say 10% at the most.

In other words, with 2 MP3s (or whatever) side by side, driven at the same speed, one with 200 lbs and one with 400 lbs of loading, the difference in fuel economy will be unlikely to exceed 10%, leave alone the 20% that +/- 10% would entail.

Even if there is a 20% difference, that still is far away from the real factor affecting fuel consumption.

3) Wind has nothing to do with wind resistance in this case. The MP3 is what it is and adding a windscreen of some sort might influence wind resistance a little.

However, the "wind" effect I was talking about was the stuff that either blows you along or across the road, or tries to blow you backwards.

Mild, gusty winds can easily affect/worsen your fuel consumption by 10%. On those rare occasions that the wind is behind you, it will help fuel consumption, but I don't find that happens very often.

1) Speed. Yep, the number one determinant of what fuel consumption you will get.

I could quite easily believe 70 mpg at 50 mph. I would then expect maybe 40 mpg at 75 mph. Or worse. Factor in a headwind and 400 lbs of rider(s) and that could easily drop to the low 30s.

These (and almost any 2 wheeler) are not very efficient at cutting through the air once you have riders on board. It's this basic wind resistance (and the unladen weight), coupled with the gearing limitations of the CVT which makes for high fuel usage at high speed.

Remember that at 75 mph the 500 is at 85% of its maximum speed. In my car at that speed the diesel engine is running at 2200 rpm out of a maximum of 5,000 rpm.... and achieves around 45 mpg(US).

Cheers

Trevor G

Ouch. Most of this makes my brain hurt! But its good someone has
some science in their craniums. I am lacking that, for sure.
I agree about the wind. Uphill and against the wind and going flat out=
low mileage for sure ( and in those conditions you WILL be going flat out- and not very fast). The wind here can be pretty tough.
I am guessing average road trip speed might be 65.
35-40 around town.

I am very excited to bring this post back from the dead. At the end of the last years riding season here in Idaho my gas mileage plummeted to very crappy mileage. Lowest was I think 38 miles per gallon. But roughly it stayed right around 42 mpg. At the beginning of this season, it still remsained crap for unknown reasons to me. I can't say this is correlated, but one day I noticed my oil filter was loose. very loose. I tightened it up good and tight, and ever since then, my mileage has been going up. Granted it has taken an agonizing 1200 miles to do so, but here is the outcome over these 1200 miles.

In MGP......42, 44, 44, 45, 46, 47, 49, 49, 49, 49, 52, 53, 54, 55, 57, and then yesterday came........headed to Salt Lake City for a tool concert and I am up to 60 mpg. HALALUAH, its only going to get better. I almost can't wait until the next fill up to see if it will go up still.

I have no idea the change, and I want to doubt the loose oil filter because that doesn't make sense to me, but then again it's gone up up up and up. I finally feel unbound from that mpg daemon. Horray, Horray, Horray.

Rob, could it be from altitude? You do live in Denver...

Along the same vein, how in the world do you reset the mileage A thingy? I looked all over the book and couldn't find it.

It's in the manual.

While on the mode 'thing' you want to reset, just hold the button in for three seconds.

Not rocket science FFS. Any ordinary primate would find this by experimentation...

Jeez, embarrassing to have this old thread brought back, where I had things so wrong......

Is it possible it could have something to do with the air humididty? I've heard drier air can make your engine breathe a lot better in two strokes. I'm not sure about fours. Especially since a computer monitors the mixture.

In Seattle I get around 52-55
I am quick on the throttle though.
I get a lot of asses in piped hondas that want to race. I beat them to the speed limit and then jam the brakes and watch them go flying. Fun stuff. Not so economical though.

Back from the trip. My highest MPG was 63.5 Avg speed 72 on the mp3 odo, not gps or any other reading. So I am very excited.

LOL Just hope some of mine don't ever come back to haunt me....hey now quit searching.

The only reason they don't is concern about payback.