barkwindjammer Posted March 16, 2011 Share Posted March 16, 2011 Turning forces, bike vs car wind resistance etc is all irrelevent the original question was based around whether the bike engine is as efficient as the car engine, and it's quite clearly not. they are equall when it comes to efficiency-because they use the same method of propulsion-an I C E Link to comment Share on other sites More sharing options...
Gas up - Let's Go! Posted March 16, 2011 Share Posted March 16, 2011 Turning forces, bike vs car wind resistance etc is all irrelevent the original question was based around whether the bike engine is as efficient as the car engine, and it's quite clearly not. It's totally relevent, as the measure you are using for it's efficiency is it's MPG which is effected by external forces, not the efficiency of the motor which is something quite different. The engine is not just propelling the bike, it's also providing the energy for all of the other factors. If you can't grasp that fundemental then you aren't going to get an answer to your initial question. I think you'll find that measuring the efficieny of the motor (heat, sound and power output versus energy input), the small forur stroke bike engine will fair about the same as the car engine, depending on if it's a single, twin, triple or four. Link to comment Share on other sites More sharing options...
oldtimer Posted March 16, 2011 Share Posted March 16, 2011 TIPS ON PUMPING GAS One of the most important tips is to fill up when your gas tank is HALF FULL. ah but is it half full or half empty $4.10 per gallon god your lucky its nearly £6 a gallon here and going up week after week. Link to comment Share on other sites More sharing options...
Leatherat Posted March 16, 2011 Author Share Posted March 16, 2011 So are you saying that, the fact that the car is 3X heavier than the bike, with all the intial engergy that requires to move it forward, has more rolling resistance, more windage regardless of it's drag co-efficient and is still producing a greater mileage per fuel used than the bike, which even with the un-aerodynamic shape is easier to initially get moving, the car has no greater efficiency than the bike? Sorry, I don't see it. All of these turning forces etc are going to be over ridden by the cars weight surely. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 16, 2011 Moderator Share Posted March 16, 2011 One of the most important tips is to fill up when your gas tank is HALF FULL. HMM so thats just over a gallon, around 45miles on the 250. Or around half a gallon, around 30miles on the DT. Don't think the stations are that close together..... Link to comment Share on other sites More sharing options...
wild foamy Posted March 16, 2011 Share Posted March 16, 2011 ITs horses for courses for example, i drive a 2002 Kia Sportage, its a 4x4, it weighs just under 2 tonnes and has a 2L petrol engine putting out roughly 140bhp, i get 25-30mpg when driving at a maximum speed of 70mph, top speed is 110 but fuel economy is terrible at that speed. However, my bike (Yamaha XJ600, '89) is used mainly for getting from A to B quicker than it would take me in the car, or cheaply. it puts out around 70bhp, weighs 230kg and 65mph is roughly 6000rpm although the average speed is usually 90mph upwards with a maximum speed of 120mph. I live on my own, i rarely have other people in the car, and unless the weather turns really bad, i need to move some stuff or pick up some mates i hardly ever use the car, so it makes more sense for me to use the bike, if you have kids or live with over people then obvious it would be a more efficient use of your time and money to use the car. Link to comment Share on other sites More sharing options...
2 Wheels Posted March 16, 2011 Share Posted March 16, 2011 On the subject of fuel.....I found this about tips of the trade TIPS ON PUMPING GAS I don't know what you guys are paying for gasoline.... but here in California we are paying up to $3.75 to $4.10 per gallon. My line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every gallon: Here at the Kinder Morgan Pipeline where I work in San Jose, CA we deliver about 4 million gallons in a 24-hour period thru the pipeline.. One day is diesel the next day is jet fuel, and gasoline, regular and premium grades. We have 34-storage tanks here with a total capacity of 16,800,000 gallons. Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role. A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps. When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money. One of the most important tips is to fill up when your gas tank is HALF FULL. The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount. Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom. To have an impact, we need to reach literally millions of gas buyers. It's really simple to do. Interesting tips there ! God help the fella waiting behind me to fill up,,,,,,,,,,,,,,,he will be waiting a long time as i DRIBBLE my fuel tank up to the full mark,,,,,,,at say 4am Link to comment Share on other sites More sharing options...
neversaydie Posted March 17, 2011 Share Posted March 17, 2011 Don't you find it gauling that as motorcyclists we are being shafted by the manufacturers over the awful fuel economy of our bikes? My current steed is a 650cc twin, it weighs 215Kg and is capable of transporting 2 adults and a small amount of luggage. Fuel economy = 40-45mpg. My last bike was a XJ900S Diversion, 900cc transverse inline 4 cylinder which weighed 239Kg and is capable of transporting 2 adults and a small amount of luggage. Fuel economy = 45-50mpg. Whereas, my Ford Focus is a 1600cc transverse inline 4 cylinder which weighs 1200Kg, is capable of transporting 5 adults and a not inconsiderable amount of luggage. Fuel economy = 37-40mpg. (as a point of reference, the new BMW 1600cc bike is reportedly only getting 22-30mpg) How can a slip of a thing such as a bike, not be attaining fuel figures far in excess of those acheived by a heavy lump of a car? Motorcycle manufacturers have fallen so far behind their 4 wheel counterparts, that we as their customers really ought to be outraged at the dinosaur like machines we are being asked to accept. Hmmmmm. So why do you ride a bike then Surely the advancements of technology which make bikes go, and stop so well should be aimed at making them go a bit further on a gallon of 4 star? Link to comment Share on other sites More sharing options...
Leatherat Posted March 17, 2011 Author Share Posted March 17, 2011 Neversay die wrote.......Hmmmmm. So why do you ride a bike then Stupid fuckin' question! I eat junk food, but would like it to be better for me..........Idiot! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 17, 2011 Moderator Share Posted March 17, 2011 Its simple really, performance sells bikes. The works Yamaha teams promote sales for fast bikes, the motocross promote sales of dirt bikes. The sensible fuel efficient version is promoted by, er, er, nope. The small capasity 250ish commuter stuff sells its self to discerning punters who want 70-80 MPG. The rest of the time as far as Yamaha are concerned with increacing MPG, is more Motorcycles Per Garage. Its the punters fault, the mainstay of motorcycles are glorified toys. You must know somebody who can throw money at his/her bike for the latest fashion. Those people couldn't give a monkeys about fuel, they want BHP. The extra 3mph over the green one they had last year is all they care about. I agree fuel economy on bikes is shite, my TDR can stretch to maybe 60mpg ridden efficiently, and that doesent mean slow. But that bike dates back to when bikes were all round items. Now they have been designed to fit a certain group. The common point in that group is the same thing we see on here week in week out. Want to go faster. If our motorcycle engines were tuned to the same level as cars they would be better on fuel. To use the focus angle here: That 1600 motor cranks out 113hp, or 70bhp/litre My TDR250 gives 50hp, thats 200bhp/litre (the 50 is due to the pv changing the engine dynamics when its open your getting 30mpg or less when its shut you have maybe 20hp so 80bhp/litre and so economy) Even the 90bhp divvy is making 100bhp/litre No mater how these engines are made and by whom bhp increaces come from burning fuel, If any of the big four churned out a spanking new bike at say 600cc giving maybe 35hp that it was designed to for economy not gutted to 33bhp by a 'kit' would give good gas milage. Cant see there being many takers though. Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted March 17, 2011 Moderator Share Posted March 17, 2011 My SV (650 V twin) carb model does 61 to the gallon in "not hanging about" mode. How do I know? I use miles travelled divided by fuel to refill the tank. I know how it is ridden and the types of roads It is ridden on. My car does 38MPG for the same journeys. I know because the computer tells me. I guess I could get a better MPG out of the SV but it would not be as much fun. Link to comment Share on other sites More sharing options...
oldtimer Posted March 17, 2011 Share Posted March 17, 2011 my triumph tt600 does 36.62mpg mostly short journeys but on a long run rises to the dizzy heights of 38.93mpg and as i dont own a car cant really compare it but if i used my old mans free bus pass would save a fortune but not have as much fun. as for all the physics in previous replies pass way over my head. Link to comment Share on other sites More sharing options...
2 Wheels Posted March 17, 2011 Share Posted March 17, 2011 Nevermind this fuel economy crap ! ! ! Get out there on your bike and burn a big hole in the atmosphere ! Especially if ya have a 2stroke ! Either the world will end in one of these natural disasters or you will eventually die anyway ! Then when ya draw your last breath,,,,,,,,at least you can say,,,,,,,,,,,,, I Lived My Life regardless of everything ! Now off ya go,,,,,,,,,,full throttle everywhere Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 17, 2011 Moderator Share Posted March 17, 2011 Funny how the people who have chipped in on this thread are year round riders........ Makes you think eh... Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted March 17, 2011 Moderator Share Posted March 17, 2011 ..................... I thought I'd given up Physics when my daughter opted for Law & Chemistry rather than good old engineering topics! I do have a newsletter from our local IAM group that explains the turning forces though - if you are interested! Dont forget coefficient friction. Link to comment Share on other sites More sharing options...
neversaydie Posted March 18, 2011 Share Posted March 18, 2011 Neversay die wrote.......Hmmmmm. So why do you ride a bike then Stupid fuckin' question! I eat junk food, but would like it to be better for me..........Idiot! Yep, so am I Link to comment Share on other sites More sharing options...
Recommended Posts