Why dont motorcycles get better MPG?

[sunruh]

tomcat you must be on a [censored] bike!

my honda cbr600f2 averaged 52.5 day in day out. for 10 years.
sure i could get as low as 50.+ if i was sitting in traffic or hammering the right hand. i also could get over 54 if i really wanted to pinch it.

 

[Zedhed]

Originally Posted By: JHZR2
everything has to be "performance oriented" and "sporty".


Yeah, ain't it cool? Who wants some wimpy, no-performance motorcycle?

"I don't need no stinking gas-saving motorcycle..."

This is a man's hobby, dweebs need not apply...

 

[boraticus]

I'd say a number of factors contribute to less than stellar mileage in bikes.

First and foremost is aerodynamics. Most cars have an aerodynamically slippery shape compared to an un-faired bike.

Next is engine design. Attaining higher specific h.p. requires performance attributes that result in the use of more fuel to make the higher numbers. However, these engines can and will deliver very good mileage if kept out of the power band.

Slippery bikes with fairings should provide better fuel consumption. The problem is that most people riding this type of bike like to go fast. Going fast requires exponentially more power thus more fuel being burned.

Generally speaking, if you drive your bike like you drive your car, in most cases, your mileage will improve. But hey! Where's the fun in that?

 

[Zedhed]

Originally Posted By: Silk
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.


Yeah, you weren't limited by the size of the gas tank on those bikes, just the ability of your arms to hold on the handlebars when they were numb from vibration.

Norton Domi was the worst vibrator ever made -- shake your eyeballs from your head. 360 degree vertical-twin? Oh, please....

 

[OilNerd]

My XJ550 gets around 50 mpg highway, riding solo. Less with takeoffs - mostly due to hard driving.

 

[Silk]

Originally Posted By: Zedhed

Yeah, you weren't limited by the size of the gas tank on those bikes, just the ability of your arms to hold on the handlebars when they were numb from vibration.

Norton Domi was the worst vibrator ever made -- shake your eyeballs from your head. 360 degree vertical-twin? Oh, please....


My 1987 R65 is roughly the same weight and size as say a 650 BSA,it has a 22 litre tank,it has 48hp...a BSA Lightning had about the same.

SO - why does the the BMW give the same performance as the BSA (with less vibration of course) but half the fuel economy?

 

[Robenstein]

My Virago 250 averages 90mpg with the lowest being 78mpg (riding hard in a bad headwind at 55mph) and the high at 98mpg with a nice tailwind.

My fathers CB750 DOHC gets 65mpg, not bad for a 79. Some HD sportsters are advertised as getting around 60mpg, not bad for a twin.

 

[jef1ge]

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.


The best I have gotten with my 06 Ninja 250 back and forth to work is 68.52 mpg at 55 MPH and not winding it up on the up shifting. But this route has alot of stops and slowdown places....If one were to ride steady 55, then I could see getting it over 70 mpg pretty easy.

Jeff

 

[eljefino]

Pretty steady 50-52 MPG from my Virago. Shaft drive precludes regearing; it's pretty short, can putter along at 25 in 5th.

Have noticed there is no way for the ignition module to detect load; if it were a car engine some more spark advance under cruise would be good for MPG. Being aircooled may not be the curse one thinks; still get cylinder head temps around 205'F on a moderate day. Nearly perfect in my book. Can wean it off choke in a mile or so.

I literally got it "to save gas" on my commute; my work is I show up and press buttons, don't need to drag four empty seats back and forth all the time.

 

[grampi]

My Corolla weighs roughly 3000 lbs and it's 1.8 liter engine gets as high as 41 MPG, but averages about 37-38 MPG. My 1.8 liter motorcycle weighs 800 lbs and gets 42 MPG. What's wrong with this picture?

 

[dwendt44]

Four wheels move the body.
Two wheels move the soul.

 

[XS650]

Originally Posted By: grampi
My Corolla weighs roughly 3000 lbs and it's 1.8 liter engine gets as high as 41 MPG, but averages about 37-38 MPG. My 1.8 liter motorcycle weighs 800 lbs and gets 42 MPG. What's wrong with this picture?


1. You didn't consider air resistance which is more important than weight on the highway.

2. You might be operating the Virago a bit more sportingly than the Corolla.

 

[OtisBlkR1]

Originally Posted By: Hermann
aerodynamics,plus what they say.


+1 aerodynamics is a VERY big part of it.

 

[grampi]

Originally Posted By: XS650
Originally Posted By: grampi
My Corolla weighs roughly 3000 lbs and it's 1.8 liter engine gets as high as 41 MPG, but averages about 37-38 MPG. My 1.8 liter motorcycle weighs 800 lbs and gets 42 MPG. What's wrong with this picture?


1. You didn't consider air resistance which is more important than weight on the highway.

2. You might be operating the Virago a bit more sportingly than the Corolla.


Whose got a Virago? Not me.

 

[Hermann]

Originally Posted By: Silk

My 1987 R65 is roughly the same weight and size as say a 650 BSA,it has a 22 litre tank,it has 48hp...a BSA Lightning had about the same.

SO - why does the the BMW give the same performance as the BSA (with less vibration of course) but half the fuel economy?


BMW's flat twins have never given stellar mileage results, I average 40-42 MPG with my R100. Although on the open road it will inch up to 45-48 MPG. If driven at 55-60 in high gear with minimal headwind it has returned 60 MPG, but I rarely drive that way. The last generation of BMW airhead twins(88-95) ran so lean to meet emissions standards, it takes them 20 miles to be fully warmed up, and to carbarate properly.

 

[wantin150]

50-53 on mine.

 

[warchildindy]

50 mpg on a 2004 HD Sportster(carb. v twin) driving like a maniac,and the same on a 2008 Triumph Sprint ST(fuel injected triple).

Who knows if I drove sensible. Aerodynamics and the power band we like, hurts us big time.

 

[whitesands]

Why don't motorcycles get better mpg ?

I've always thought that motorcycles got pretty good mpg...Maybe not to the extent that one may think given the engine size and such....But most bikes easily get (not all but most) anywhere from 40 to 60 mpg on the highway riding normal...Now consider that many of these bikes can also do 0-60 in less than 4 seconds (some less than 3 seconds) and still get well over 40 mpg...Real impressive.