There are numerous cars (not hybrids) that get 40mpg. so... why cant we get much better MPG with a bike? many mid-sized bikes barely get more than low 40's for mpg.
Why dont motorcycles get better MPG?
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Gearing and rich mix...?
The efficency at 12,000 rpm @ 175 mph is probably close to 100% on some of those machines.
JHZR2
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everything has to be "performance oriented" and "sporty".
Hermann
Site Donor 2023
aerodynamics,plus what they say.
A lot of it is rider.
Short shift and ride at the same performance level as a 40mpg economy car and you will get better mileage.
Part of it is that motorcycles sold for use in the US tend to be performance oriented with highly tuned engines. An exception is Harley which gets surprisingly good mileage if driven like a little old lady.
Hermann also made a good point, MC aerodynamics are pretty bad. The difference in power to move a motorcycle at freeway spped and move a motorcycle at highway speeds is no where as big as you would guess from their sizes and weights.
Short shift and ride at the same performance level as a 40mpg economy car and you will get better mileage.
Part of it is that motorcycles sold for use in the US tend to be performance oriented with highly tuned engines. An exception is Harley which gets surprisingly good mileage if driven like a little old lady.
Hermann also made a good point, MC aerodynamics are pretty bad. The difference in power to move a motorcycle at freeway spped and move a motorcycle at highway speeds is no where as big as you would guess from their sizes and weights.
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Originally Posted By: willix
The efficency at 12,000 rpm @ 175 mph is probably close to 100% on some of those machines.
They are called the "Laws of Thermodynamics" and not the "Suggestions of Thermodynamics" for good reasons.
The efficency at 12,000 rpm @ 175 mph is probably close to 100% on some of those machines.
They are called the "Laws of Thermodynamics" and not the "Suggestions of Thermodynamics" for good reasons.
My 77 Kz1000 gets around 35 mpg. considering the fact that it is set up for power, and a 4 cyl, and it's from the 70s, I'd say it does alright. Those I know with 2 cyl 400s, or ninja 250s that get 50ish mpg. I imagine a small displacement EFI bike would do better on mileage than my gas guzzling monster from the 70s.
The old British bikes got very good mileage - My Triton with pre unit 650 with all the fruit used to get 100mpg,my Norton 600 domi SS used to get 95mpg,my wife's '51 T100 used to get 95mpg too.
Today I still ride a 650cc pushrod 2 valve twin - and it gets 48mpg.So what happened?
These are Imperial gallons.
Today I still ride a 650cc pushrod 2 valve twin - and it gets 48mpg.So what happened?
These are Imperial gallons.
Interesting, I would say my dads bike is midsize and he gets 55-60 miles to the gallon
At some point, you don't gain any more efficiency by making an engine smaller.
Maybe the ratio of internal surface area (friction) to internal volume (power) is higher?
I do know the really fuel efficient cars have specifically tuned exhausts to keep EGTs and exhaust gas velocity high. Maybe motorcycle pipes are too short to make that happen. I'm also pretty sure no one would want a bike with tiny pipes...
Maybe the ratio of internal surface area (friction) to internal volume (power) is higher?
I do know the really fuel efficient cars have specifically tuned exhausts to keep EGTs and exhaust gas velocity high. Maybe motorcycle pipes are too short to make that happen. I'm also pretty sure no one would want a bike with tiny pipes...
Originally Posted By: u3b3rg33k
My 77 Kz1000 gets around 35 mpg. considering the fact that it is set up for power, and a 4 cyl, and it's from the 70s, I'd say it does alright. Those I know with 2 cyl 400s, or ninja 250s that get 50ish mpg. I imagine a small displacement EFI bike would do better on mileage than my gas guzzling monster from the 70s.
My 1997 Suzuki GSF1200 (Bandit) would get 55 mpg if I rode the speed limit and short shifted. I didn't ride the speed limit very often but did sometimes when riding with conservative riders. Any kind of riding I usually got about 10 mpg better than people riding identical bikes because I was usually 1 or 2 gears higher than they were.
My 77 Kz1000 gets around 35 mpg. considering the fact that it is set up for power, and a 4 cyl, and it's from the 70s, I'd say it does alright. Those I know with 2 cyl 400s, or ninja 250s that get 50ish mpg. I imagine a small displacement EFI bike would do better on mileage than my gas guzzling monster from the 70s.
My 1997 Suzuki GSF1200 (Bandit) would get 55 mpg if I rode the speed limit and short shifted. I didn't ride the speed limit very often but did sometimes when riding with conservative riders. Any kind of riding I usually got about 10 mpg better than people riding identical bikes because I was usually 1 or 2 gears higher than they were.
Yes - that's one of the reasons my bikes always perform better than others,and get better fuel economy I guess.Why spend so much money on improving performance,when you could save money by eating less...and go faster.
I always cruise in 5th on mine once I'm up to speed.
So long as the engine is turning fast enough to ensure proper operation (it is an old ITB bike, remember, you can't drive it at car like operating speeds), I am in the highest gear I can be in. It's got enough displacement to provide enough acceleration in any gear.
So long as the engine is turning fast enough to ensure proper operation (it is an old ITB bike, remember, you can't drive it at car like operating speeds), I am in the highest gear I can be in. It's got enough displacement to provide enough acceleration in any gear.
Originally Posted By: willix
The efficiency at 12,000 rpm @ 175 mph is probably close to 100% on some of those machines.
Sorry guys, but gasoline engine efficiency is rather small, typically 25% only. That means that much of the energy from burning the fuel is lost (usually in the form of heat), and not used for moving the vehicle.
See http://en.wikipedia.org/wiki/Engine_efficiency
The efficiency at 12,000 rpm @ 175 mph is probably close to 100% on some of those machines.
Sorry guys, but gasoline engine efficiency is rather small, typically 25% only. That means that much of the energy from burning the fuel is lost (usually in the form of heat), and not used for moving the vehicle.
See http://en.wikipedia.org/wiki/Engine_efficiency
My 2007 FZ6 will get mid 50's on the highway, as long as I stay below 80 mph. Around town I get 41-44 mpg, and if I am running it hard on the back roads I have gotten as low as 32 mpg. Motorcycle aerodynamics are not that great, especially with a rider sitting in the path of the wind. If you put my FZ6 powertrain in a aerodynamic 400 lb vehicle, you could probably get pretty good fuel mileage. As it stands, I have no complaints with my bike, for a 600 cc four with 100 hp and a 14,000 rpm redline, the fuel economy is actually pretty good.
I have gotten 36.5 mpg with my 1998 Corvette on trips (level road). With 345 HP, that is some economy car. Note: Road and Track has listed Corvettes as an economy car !
As mentioned, aerodynamics are a key. Not sure, but I think a Corvette is equivalent to about 2 square feet aerodynamically. GM worked hard on getting the Corvette's low (they even put smaller tires on the front than the older Corvettes, although the back end also has a lot to do with it). That and a 6-speed with 2 overdrive gears, heck I'm only turning about 1100 rpms in 6th at 55 mph, gives incredible mileage.
As mentioned, aerodynamics are a key. Not sure, but I think a Corvette is equivalent to about 2 square feet aerodynamically. GM worked hard on getting the Corvette's low (they even put smaller tires on the front than the older Corvettes, although the back end also has a lot to do with it). That and a 6-speed with 2 overdrive gears, heck I'm only turning about 1100 rpms in 6th at 55 mph, gives incredible mileage.
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