My Forza has averaged 78mpg over 6000 miles commuting.
The highest it has achieved was 105mpg on a journey of 20 miles.
The PCX got about 90ish over the same commute.

This is interesting, so thank you for all your replies.
Do you think scoots could be more fuel efficient, or do you think they're about at their optimum fuel efficiency level already? For instance do you think it would be possible for a manufacturer to produce say, a 250 scoot which could attain 90mpg on a regular basis without having to go everywhere at 30mph?


Also, could machines be made lighter without adding too much extra cost, or are the manufacturers just being lazy so to speak?

I use the Carango app on my Android phone to monitor fuel consumption. I use my bike for work commute and running around Brighton and have not done many long trips during winter and according to the App the Maxsym 400 average milage as been 65.12 (min : 55.62, max: 76.85)

Here are my meagre findings:

K8 400 60 - 65mpg around town
Vision 110 110 - 120 mpg around town (the higher figure if I'm pootling along with no WOT)

All my other bikes? I never knew their consumption as I was too busy 'hooning it' or putting on the miles or polishing them

Tim

wozza wrote: For instance do you think it would be possible for a manufacturer to produce say, a 250 scoot which could attain 90mpg on a regular basis without having to go everywhere at 30mph?


Also, could machines be made lighter without adding too much extra cost, or are the manufacturers just being lazy so to speak?

It would be possible to build something that averages well over 100mpg but it wouldn't as cheap to manufacture as the current crop of 300 scoots.
Weight savings could be achieved but lighter isn't always better.

Weight is going to affect acceleration more than MPG - cars accelerate slower than bikes because they are heavier but they can get better mpg thanks to aerodynamics.

What Globs says is broadly true but only if the shape remains the same - a 50cc bike will do 130mph if you get the shape right - so power isn't the only factor in gaining higher speeds

Allert Jacobs got over 220mpg out of a Honda Innova by reducing the drag with smooth bodywork and making it heavier, not lighter.

Aerodynamics are the big killer for mpg.
Bikes have crap drag, they are tall and have lots of components sticking out all over the place that all crash into the air, sometimes one behind the other. Then they leave a big empty space behind them that tries to suck you backwards - horrible.

A car is bigger and heavier with a bigger engine and probably a higher top speed but it can still get similar mpg because it has less drag. The car is smoother with less sticky out bits.

So why aren't bikes all more aerodynamic?
Well partly because it costs money and most bikers won't pay the extra.
On top of that a low drag bike will tend to have a very low riding position and a fully enclosed body. This takes away things that bikers say they like (simplicity, the high viewpoint and being exposed to the elements/being able to jump on and off). The extra bulk makes filtering more difficult and something has to be done about putting your foot down when you stop or having a device that can do it for you.

Several organisations have come up with what are now called "feet forward" bikes, the ones Irev likes (how come you don't ride one Irev, is it just the cost/spares thing or something else?).

Ive played around with enclosed aerodynamic bodywork myself and I got put off:
The low seating means you are trying to look through cars rather than over them
There are extra handling advantages to having your arse right on the deck, but disadvantages too
The low seating means you don't get much leverage with your legs for duckwalking/catching a slip
Contraptions to replace your legs are a complicated pain in the bum.
Ventilation/condensation is a major problem in close fitting bodywork and it is more complexity and cost to sort it out.
I may as well be in a car with all its comforts.

lighter weight and efficient engines obviously have an effect but it is aerodynamics that give the bikes their poor mpg at the moment

There are loads of factors regarding scooer size and mpg. Whilst a small scoot (say a 125) ought to be economical, the reality is that it is likely to be ridden at full throttle all the time to achieve a decent speed. A bigger scoot ridden at the same speeds could well be as or more economical. My old Skipper 125 4-stroke - I only got 70mpg most of the time cos I was riding flat out to keep up on dual carriageways. If ridden more gently, it easily got into the 80s mpg.

The other big factor is wind resistance. I know that the consumption of the TMax becomes truly awful if speeds in excess of 80 (on my private test track) are maintained for any length of time. And of course, its working quite hard at those speeds as well - hence big touring bikes with engines well over twice as big can probably match the Tmax's M-way fuel consumption.

Absolutely, and there is gearing too.

But it is drag that is the root cause of those problems - your 125 wouldn't be working as hard at the same speed and your Tmax wouldn't have the wind resistance if the drag was reduced (wind resistance is drag)

My X9 does about 65mpg

Aerodynamics is the KEY. After my brother and I changed-out our horribly-buffeting Tmax500 factory windscreens for GIVI AirFlows, a few things were instantly noticeable:

1.) buffeting was GONE, along with 80% of the wind noise
2.) hands and chest were now OUT of the wind stream
3.) bikes were MUCH more stable in severe crosswinds, passing large trucks, etc.
4.) less throttle was required at 75mph cruising
5.) top speed went UP more than 5mph
6.) mileage INCREASED about 5%