Most mopeds that I know use regular gas, no need for mixing anything. Here is a useful link that explains it Jujubee: http://www.k-wz.de/vmotor/v_omotore.html

Short answer: You won't need to mix oil into the fuel if you get a 4 stroke and you'll pollute less. More: You could even get an electric moped if you wanted to pollute even less. For a 2 stroke, you can get premixed fuel/oil if you don't like to mix it yourself. More and more scooters are coming equipped with four stroke engines due to their dependalablity and ease of care. While most scooters were two stroke up until 2004 most manufacturers are producing four stroke models due to the disadvantages of a two stroke engine. Without getting too deep in into how two stroke engines work we will just look at the disadvantages of two stroke motors in that they do not use fuel efficiently, so you would get fewer miles per gallon, produce a lot of pollution -- so much, in fact, that it is likely that you won't see them around too much longer. Two-stroke engines don't last nearly as long as four-stroke engines. The lack of a dedicated lubrication system means that the parts of a two-stroke engine wear a lot faster. So you see the newer four stroke models that are coming out of which there are plenty of models to choose from offering both 49.5cc and 150cc. A four stroke model is a more reliable scooter to operate getting better gas mileage and ease of care. Other huge advantage four stroke scooters have over two stroke models is storage, a two stroke model stored over long periods of time like the colder winter months will form a varnish type film over the carburetor jets clogging them with oil and making start virtually impossible with cleaning carburetor which means removing from the scooter. Keeping the oil changed in a four stroke motor is easy and can be done in about fifteen minutes, not much time compared to keeping the two stroke oil plentiful plus a clean spark plug and a finely tunes carb on a two stroke model. Consider the advantages of a four stroke over the two stroke before buying. Some other pros and cons: Advantages: - Two-stroke engines do not have valves, simplifying their construction. - Two-stroke engines fire once every revolution (four-stroke engines fire once every other revolution). This gives two-stroke engines a significant power boost. - Two-stroke engines are lighter, and cost less to manufacture. - Two-stroke engines have the potential for about twice the power in the same size because there are twice as many power strokes per revolution. Disadvantages: - Two-stroke engines don't live as long as four-stroke engines. The lack of a dedicated lubrication system means that the parts of a two-stroke engine wear-out faster. Two-stroke engines require a mix of oil in with the gas to lubricate the crankshaft, connecting rod and cylinder walls. - Two-stroke oil can be expensive. Mixing ratio is about 4 ounces per gallon of gas: burning about a gallon of oil every 1,000 miles. - Two-stroke engines do not use fuel efficiently, yielding fewer miles per gallon. - Two-stroke engines produce more pollution. From: -- The combustion of the oil in the gas. The oil makes all two-stroke engines smoky to some extent, and a badly worn two-stroke engine can emit more oily smoke. -- Each time a new mix of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port. Detailed explainations: On a 4 stroke, when the piston moves down fresh air and gas is sucked inside the cilinder from the carburettor. When the piston moves up again the valves are closed and the air is being compressed. When the piston reaches it's highest position the sparkplug produces a spark that ignites the fumes and causes an explosion. Because of the power of the explosion the piston is pushed back. When the piston moves back up again the exhaustvalve is open and the fumes are pushed out the cilinder. Now the whole process restarts (exactly after 4 strokes. That's why we call it a 4-stroke engine...Duh!). The 2-stroke engine works a little different. It performs 2 strokes at the same time (twice) so after only 2 strokes the whole process restarts. A two stroke engine uses the space above and below the piston. Below the piston are fresh gasses, above the piston these gasses are ignited. Assume the piston is in the lowest position with fresh gasses in the cilinder above it. When the piston moves up, these gasses are compressed, but at the same time teh airpressure below the piston drops and fresh air is sucked inside. When the piston is in it's highest position the sparkplug ignites the gasses and the piston is pushed down. About halfway down a channel from the fresh gasses to the exhaust gasses opens and a channel to the exhaust. Because of airpressure differences the fresh gasses flow inside the cilinder pushing the exhaust fumes out. Now the process starts again. As you can see this only took 2 strokes. But which one is better?!? Of coarse "we" 4-stroke people say 4-stroke, but do you know why?? Probably not, so I'll explain. First I'll name some of the advantages of the 2-stroke engine over the 4-stroke engine. * When the engine is reving at 10000rpm the 2-stroke engine ignites gasses 10000 times per minute while 4-stroke engines ignite only half. So it should have twice as much power, right? * The 2-stroke engine does have channels for air transport but the piston opens and closes the channels, in a 4-stroke engine there are seperate valves and a camshaft that do this. This means extra moving parts and a far more difficult cilinderhead design. Because of this maintenance is more difficult. * 2-stroke engines give more power. At 50cc races 2-stroke bikes can reach speeds of over 130km/h while 4-stroke bikes can hardly reach those speeds with 70cc!! The same applies to everyday use. When you remove some restrictors from a scooter it will go 80km/h. You won't reach these speeds with you're 4-stroke bike by just removing some restrictors. What about the advantages of 4-stroke bikes? Are there any? OF COURSE! LOTS!! * So what does a stock 2-stroke bike use? About 1 liter fuel per 35km. What does a stock 4-stroke bike use? About 1 liter fuel per 50km! * 2-stroke bikes burn oil!! This absolutely doesn't give them more power and is of no use at all (for ignition pusposes), all it does is clogg up the exhaust and smell bad! So why they do it? They have to lubricate the cilinder and cilinderchannels big time or the engine will be wrecked... * Look at the cilinder(head) of both engines. Notice the HUGH cooling fins on the 2-stroke engine. Heck, some of them even have forced air cooling or even water cooling.Did you burn the fuel for heat!?! I don't think so! 2-stroke bikes waste much more energy on heat than a 4-stroke bike does so the 4-stroke engine is much more energy efficient. * Did you read the part on how the 2-stroke engine works?? Did you notice fresh fumes are used to push out the exhaust fumes?? Of course these two gasses will mix in that process, so or fresh fumes are pushed out too or exhaust fumes stay in, either way, it's bad and it sucks. * Ever tried to speed up a 2-stroke bike?? So fast that it could do speeds of over 100km/h. If you have you know you have to add lots of extra oil to the fuel and even than it's a big problem to keep the engine running for let's say a couple of months without mayor engine damage, wasted cilinders and screwed up pistons. Take a 4-stroke engine on the other hand and it will keep running fine for months and months and months... without extra oil ;) The reason is that because of those channels in the cilinder it's much harder to keep it lubricated enough all the time. The 4-stroke engine doesn't have this problem because it has no channel in the cilinder. * Have you ever drove on a Honda MT/MB or anything comparable with a fast cilinder? Did you notice it only had power between about 9000 to 12000 rpm?? Take a 4-stroke engine and it will have power from 1000 to 12000rpm. No problem! The reason is that such a 2-stroke cilinder has optimized airflow channels for that rpm range, outside that range the whole gas mixture gets screwed up big time. That's why those scooter engines always run at almost the same rpm. To optimize airflow, without that a 2-stroke engine looses a lot of it's power. * Because of technical aspects the 2-stroke engine can only have it's intake channel open only half as long as the 4-stroke engine...What a pitty :) * Listen to the sound of both engines...Doesn't need further explanation I suppose. Yeah, yeah, I know, 2-stroke bikes with the same displacement are faster, but look at it in another way. A 50cc racing 2-stroke engine will use over a liter per 10km. Now take a 4-stroke engine that uses the same amount of fuel. I guess you would end up with a 90cc or even a 106cc with a 26mm carb or something. No try beating such a machine with that crappy 50cc racebike thing :)

A 4Cycle Engine is WASTEFUL!!! As the Piston moves down, it draws in Fuel & Air. When it goes back up the Valves both close & an Explosion Occurs (Power Stroke) forcing the Piston down & back up pushing the Burned Gasses out the now opened Exhaust Valve. The "Stored Energy" in the "Flywheel" closes the Exhaust Valve & opens the Intake Valve now & as the Piston goes back down it sucks Fresh Fuel & Air in for the next Explosion which will happen when the "Flywheel" pushes the Piston up Again for the "Power Stroke". Every time a 2 Stroke Piston goes up, it "Fires" (Power Stroke)because there is no "Moving Valve Train" with the Scavenged Loop Design"!!! Even if U buy a 2 stroke engine, Today there is NO MIXING INVOLVED FOR U!!! Unlike his "Weed Eater", 2 Stroke Motor Cycle Engines have a small "Tank/Reservoir" into which U would pour a Qt. of oil. The Engine pumps Oil out of this tank & mixes it automatically & precisely for U, No Muss, No Fuss!!! With this system there are also No Filter & Oil Changes to do!!! And a 2 Stroke Engine is 3 times more Efficient than a 4 Stroke Engine!!! Every time the 2 Stroke Piston goes up the Cylinder, it causes a "Power Explosion/Stroke" unlike a 4 Stroke Engine which "Fires/Explodes" only once for every 4 times the Piston goes up ( more wear & Parts to be worn for what U really get)!!! I would more concern myself with matching Ur Physical Size to the size & power of the scooter needed so U can Safely Handle it in traffic. Vespa, Honda & Yamaha all make good products, have a list of questions & comfortable Clothing on when U go shopping. Test drive them, open them up with the sales person & discuss the maintenance needed & if U can do it. Read & Understand the Warranty. Take home & study their brochures & Always ask Questions for this is how U will Learn & make Informed Desisions from a Position of Knowledge.Keep in mind the old Military Acronym, (K)eep (I)t (S)imple (S)tupid (KISS). Look for a "Simple Design", well "Laid Out" & "Easy to Work on". http://en.wikipedia.org/wiki/Four-stroke_cycle http://www.oldengineshed.com/twocycthry.html John