MPG Rating Method

[skuttadawg]

We have all seen some that claim 100+ MPG or so but at what speed ? I was scooter surfing online looking at parts and I saw ads for SYM brand scooter ( forgot to bookmark the URL ) and it said the MPG was at 26 MPH instead of 55 like EPA does or at least I think so . I looked all over but could not find info on scooter speeds the test to find the MPG . So alot of the MPG claims like in the list I posted in another thread might not be true or only true if creeping instead of road speeds .

I did find out that manufacturers mustwarranty the emissions for 5 years or 30k miles depending on engine size . So for those who had burned out mufflers and above 49cc might be able to get a new one for free if defective . 49cc is not under as much EPA restrictions like larger ones .

If you increase the displacement your are considered a manufacturer and emission tampering can be a fine up to 3,250 per vehichle .

Even though I do jack rabbits starts at the lights ( to keep plenty of space between me and cars ) which is wasteful and uses more gas than cruising , I still try to stretch my fuel . What I do is simply back off the throttle to the least I can to maintain desired speed and it really makes a difference . Going at WOT you burn more gas and take in more air which you can hear the draw of it from the engine . Backing off saves gas and runs cooler . I could feel the temperature changes when under a load or not through the seat . Keeping your scooter tuned , tire pressure to specs and always try to have full tank should help your mileage , along with avoiding gas with ethanol added to it .Ethanol burns up faster and only has a 90 day shelf life . E10 = 10%ethanol 90%gas you lose 10% of your MPG . Its stupid to ad potential taxable moonshine to gas instead of making spirits . Maybe one day we will have a real Green fuel , that we grow ourselves and keep our money in our economy

I do enjoy a fillup for under 5 bucks of premium and laugh at cars requiring 50 or more to do so . I also love to tell them how I get 80 MPG lol

[mainepeace]

In theory, the BEST MPG you can get is at peak torque. Of course, this is also affected by the gearing as you could have it in a really high gear and lose mileage due to the extra load on the engine.

You could figure it out if you really wanted to. Basically, figure out the EXACT distance you travel per two crankshaft revolutions (4 full strokes) at a particular speed, RPM, and gearing ratio, and throttle position. Typically an engine is less efficient at full throttle as opposed to 3/4, but that varies depending upon the engine design. Most engines seem to be more efficient at around 1/3 throttle if I remember correctly.

Creeping along I believe you would get much worse gas mileage as you are losing more power (fractionally speaking) to friction than at a higher speed. Of course you will get wind resistance which increases with speed as well.

For gearing, I believe you should be at the minimum speed to have the variator FULLY closed. That way you get less heat due to belt flex and friction along the face. Just a thought.

If you tune the variator for that to happen at your MAX torque, then I bet that will be the ideal setup for maximum MPG.

Just speculation.

Greg

[quest4fire]

My Heinkel owners manual has precise graphs of torque, mileage and horsepower at different speeds. Fuel efficiency peaks well below the top recommended speed of 57mph, at 90 mpg, drops to 80 at 45 and 70 at 55. I found synthetic oil (Mobil 1) after a complete rebuild improved it so I get 80mpg at 50-55. Lots of hills here.

[trailheadmike]

I'm jealous every time I see these threads. My 260 only gets in the mid 40s (real miles, not china miles. My odometer is off like my speedometer). I'm 230 lbs, my route is very hilly and all start and stop, but still. Its better than my car though, and an incentive to lose weight.