Modern Vespa

so what scoot out there, that can take to the expressways, is the top of the heap in regards to mileage (Gas scooters only)

A 150 is technically highway capable and highway legal in I believe, all 50 states. A 125 is technically highway capable and legal in some. One of those would easily get the best mileage. In order to answer this question better we need a specific engine size.

I think the Vespa 250 and 150 get about the same mpg. I get about 75mpg out of my 250.

me too (75 mpg).
Best
Miguel

I think mileage has a lot to do with how high the RPMs you are working in and how open the throttle is.

Following that line of thought, at a given speed (let's say 60mph) a larger more powerful engine could, POTENTIALLY get better fuel economy than a smaller weaker one, by virtue of the fact that the scooter might be running at lower RPMs and a more closed throttle position.

I've observed, for example, that I get similar if not better fuel economy around the city on my 200 than I do on my 50. Why? Because I ride around the city at 35mph two-up - on the 50 I'm doing this WOT and max RPM, while on the 200 I'm barely puttering along. The 200 doesn't blow the 50 out of the water because it inherently sucks more gas (larger displacement with larger carb and larger jets plus more weight), yet much if not all of its disadvantage is made up for by how easy it is being ridden in that scenario.

So, I would speculate, that at 60mph, a 250 might easily get the same mileage as a 150, perhaps better, given that the 150 is working its ass off while the 250 still has more "leg room."

All things equal. I mean, if the 250 was also a trillion pounds heavier than the 150 and had the aerodynamics of a semi truck, it probably couldn't make up the difference. But given that a GTS is still a "small" vehicle and is aerodynamic (yes, it is bigger and boxier than an LX, but anecdotally from our users it isn't bad enough in those fields to give the LX an edge).

I've owned lots of motorcycles (15+) but only four scooters: an Aprilia Atlantic 500, a Vespa GT200, a Suzuki Burgman 400 and my current Vespa GTS300. Though all are expressway capable, the 200 never felt very expressway 'comfortable.' At freeway speeds, the two maxi-scooters would easily delivery better mileage than my current Vespa - as their engines weren't working as hard as the Vespa engine is. They'd be in the mid-50 to low 60 mpg range (depending on traffic) while cruising in the 75-85 mph range. The Burgman had the added plus of using 'regular' grade fuel, vs the Aprilia's need for 'premium' and, though the Aprilia was a little bit faster, the Burgman had much better handling and was more all-day comfortable. The even larger twin-cylinder scooters (the Honda 'whatsit' and the Burgman 650) are even more powerful, but do not have particularly good fuel mileage. In my opinion, the Suzuki Burgman 400 would be at the top list for an expressway capable machine with great mileage (and on a less expensive grade of fuel). I do prefer my Vespa GTS300 for many other reasons.

On a trip from LA to San Diego and back last year - 150 miles of freeway riding each way - I averaged 60 mpg on my MP3 400. I have windscreen and a top box. I think aerodynamics are an extremely important part of mileage at freeway speeds.

Extensive experience with 125, 250 and 500cc X9 scooters made it very obvious that the 250 engine (carb'd in those) was the 'sweet spot' as far as fuel economy went.

I'd expect there to be almost no difference between a 250 and 300 running at a constant 65mph. It's an easy cruising speed where you aren't having to use full throttle.

By contrast, a 150 at the same speed will be pretty much flat out and operating outside it's most efficient speeds.

Go much above the 250/300 and the larger capacity engine will again be less efficient.

I totally agree with all of the above. I can get 80 miles to the (imperial) gallon from my GTS300 at a real 65mph. I did feel that my previous GTS250 was very slightly more frugal. The 250/300 class is a good compromise between highway compatibility and good gas mileage. I just wish they had bigger tanks. I'm refueling every day for my commute.

Paul.

My 500cc beo is more efficient on the highway than my 250cc BV. They are both injected too.

In MA you can not take a 150 on interstates.

http://www.tourtank.com/ttproducts.html