Mythbusters: Is a bike greener than a car?

[sendler]

Originally Posted by ProDarwin

Cool. I wonder what the effects would be following non-CA US laws? Bikes here can't legally lane-split, lane-share, etc. As far as the space they take up, not much different than a Smart car really.

Two motorcycles in one lane is legal everywhere and even when staggered by a bike length, they take up half the space of a car. Too bad the Smart car only gets 45 mpgUS.

[ProDarwin]

Originally Posted by sendler

Two motorcycles in one lane is legal everywhere and even when staggered by a bike length, they take up half the space of a car. Too bad the Smart car only gets 45 mpgUS.

Huh, you are mostly right.

Lane sharing is illegal here though (VA). Motorcycle Riding Laws by State

There does appear to be a gray area regarding "abreast". LIS > Code of Virginia > 46.2-857

Either way, our roads could never legally look like they do in that study.

[RiderofBikes]

Idk about you guys, but the talk about tyres is completely moot... As the "average person" buys tires that are cheapest and are usually not taken care of properly in the long run, result in premature wear or failure. WE, as in Eco nuts, do however take pride in our maintenence and upkeep.

Personally I choose not to rotate my tires, while the result of uneven wear accures, I also keep my tires evenly pressurised and aligned properly to prevent further wear.
My fronts as noted by other operators of their own vehicls wear faster(obviously) especially in FWD configurations. They are the ones that suffer the most abuse across their life span. Turning(wheel scrub), hard accelerations, braking, and higher friction by the vehicle unequal weight distribution. The rear of a RWD car can also have a similar outcome as bikes do, dew to the torque wearing down the tread faster from acceleration alone.

My OEM Kumho, since driving off the lot(15mi) now have roughly 35700mi, and the tread depth is still 7/32 frontleft, and 8/32 front right. While my rears are still ~27/32. I can Rotate/Balance along with an alignment be able to rack up another ~22,000mi with the better wheels up front. Then, I will NEED to replace my entire set of tyres. I have also acheived more than 40kmi+ with crappy Douglas tires on a boat of a car(becasue i didn't drive like an idiot). I used them within their manufactured capabilities.

I have also owned many bikes, Touring tires can and will go for a least 15-20kmi easy for most larger bikes. Some more $$$ can last for 40k. Even the cheapest tires for me have lasted no less than 10k mi before compromised handling in wet and aggresive riding occur... Even sticky bald race take-offs can last another 3-4k(summer use) for a marginal $20-40 per tire.

While bikes go through more routine maintenence, they also use(dependant of size) 1/2 the amount of engine oil, during a 2-4kmi period. use 2/3 less fuel or more(less?), go threw a given season of more tires(but equal to resources used to make common set of car tyres). Depending on Bike campared to Car, will cost less to insure.

I see it, regardless of Emissions, both are equal to a degree, pending your Practical Needs and how You take either vehicle and Incorporate it in your day-to-day life. Most have both to accomodate their needs... To each their own

[serialk11r]

I don't have personal experience with the ultra sticky type of tire but I know that Dunlop Star Specs seem to be a popular performance tire, and it seems that owners are happy to have them last anywhere near 20k on the street. Supposedly, this is considered pretty good tread life for a performance tire, some other popular tires are claimed to wear down much faster. My car is currently wearing high performance rubber, pretty fresh rubber all around...previous owner said the rear tires get chewed up pretty fast, we'll see what happens. I don't drive much.

By the way, the old CBR250 which hit 19000rpm and had carbs and distributor supposedly got 94mpg rolling along at 37mph, says Wikipedia. Not bad for a similar power to weight as an E46 BMW M3 with a light rider.

[cRiPpLe_rOoStEr]

Considering the lesser fuel consumption, lesser amount of materials required to make the vehicle, and lesser pressure over the soil (considering a trail/off-road environment), motorcycles seem to be "cleaner". The chain-drive in the cheapest ones can be considered a critical point for the motorcycles, but their overall running cost (which is what matters after all) is still lower due to the fuel-efficiency and lesser amount of other components to be replaced (tyres, spark plugs, brake pads, among others). Also, considering the increasing popularity of electronic fuel-injection even in some entry-level motorcycles is having a significative effect to meet tighter emissions standards.

Originally Posted by Frank Lee

Regardless of Mythbusters, even if a particular bike model and car model got identical fe, the bike used about 1/5 the materials to make, especially oil-based plastics. There's a lot of emissions in manufacture and disposal too.

I'll second that. Another point which is particularly critical where I live is the disposal of worn-out tyres, which often are left exposed to the weather, becoming an environmental hazard due to rain water accumulating inside them and then generating a favorable environment to the reproduction of the Aedes aegypti mosquito.

[sendler]

More motorcycles that are lane splitting save car drivers time too.
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Why commuting by motorcycle is good for everyone - Telegraph
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[IamIan]

Originally Posted by sendler

If you are getting 70 in your Insight, your average speed must be pretty slow.

Have you done a speed vs MPG chart yet for your bike? ... I didn't notice it on that thread ... I think it would be interesting... Link

From my own experience average speed does not have to be "pretty slow" for a Gen-1 Insight to get 70+ MPG ... bellow is the speed vs MPG chart MetroMPG did for a Gen-1 Insight.



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I expect YMMV applies ... There are too many variables to have one (car or bike) be a winner all the time , for all bikes , vs all cars, for all drivers, in all conditions.

Bikes have their pros and cons ... cars have their pros and cons ... whatever you like to drive ... have fun and be efficient with it.

[sendler]

Speed vs consumption charts are only possible with an onboard computer or a scan gauge. Neither of which works with most motorcycles.
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That and all you guys must have magic Insights. Those charts are fun to look at. I have an Insight. I have put 150,000 miles on it over 7 years. I know the car. My best two tanks were 69 mpgUS at 65 mph even with safe drafting of large trucks. More usually around 66 mpg summer and 58 in the winter slush. That chart is way high on the slow end. That is some brief optimum on a computer that is very optimistic. Highly modified plug in Insights can do 100mpgUS tanks (with unaccounted for wall power) at 30 mph which is stupendous, but fall right back to 70 mpgUS at 65mph on a long highway trip.

[IamIan]

Originally Posted by sendler

That and all you guys must have magic Insights. Those charts are fun to look at. I have an Insight. I have put 150,000 miles on it over 7 years. I know the car. My best two tanks were 69 mpgUS at 65 mph even with safe drafting of large trucks. More usually around 66 mpg summer and 58 in the winter slush. That chart is way high on the slow end. That is some brief optimum on a computer that is very optimistic. Highly modified plug in Insights can do 100mpgUS tanks (with unaccounted for wall power) at 30 mph which is stupendous, but fall right back to 70 mpgUS at 65mph on a long highway trip.

Mines not magic ... A 2000 I've had for ~10 Years ... I stay close to the posted speed limit ( +/- 5 MPH ) ... and other small tweaks ... and getting between 75 MPG to 80MPG is the norm for my current commute.... YMMV.

Without knowing more of your details I can't give you specific tips for improving ... but in general I would say the Gen-1 Insight is a car that will show significant differences from what would otherwise be small influences in other cars ... any vehicle benefits from a driver experienced with it ... but the Insight in particular I think benefits more than the norm.

I don't see how MetroMPG's chart can be optimistic when it is the data he collected ... nothing optimistic about documented results ... those are not estimates ... but reasonably controlled test results.

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Originally Posted by sendler

Speed vs consumption charts are only possible with an onboard computer or a scan gauge. Neither of which works with most motorcycles.

Then I have an idea for your next assume / fantastic project

Think of all the other bikes out there that would love to have it too.

You already have the speed and distance information via the vehicles on board vss signal ... can't have a speedometer without it.

The other missing piece ... you need to also log the vehicle's real time fuel consumption ... with known information about the ICE , fuel pressure , and fuel injector ms ... that real time fuel use can be calculated ... and if the bike is running with no idea of how much fuel it is injecting ... than you might have to get a flow rate sensor.

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The really low tech ... option... not quiet real time , but can give similar type of useful data about the vehicle fuel consumption at various average speeds.

Use Mile markers on road for distance ... stop watch for time ... and a finite known amount of fuel ... 1/10 gallon , etc ... Go some distance (ideally flat and level road) at some time ( this determines average speed ) ... and if you only had ___ Gallons in the tank that it used ... then you know how much fuel it used to cover that distance ... repeat with different average speeds to build up a chart.

The only part this method would loose would be the fuel used to accelerate up to speed ... but that itself could be quantified with various runs of small known amounts of fuel as one accelerates up to various speeds.

And with less mass ... a motorcycle should need fewer joules to accelerate up to any given speed.

[fidalgoman]

Craig Vetter does a motorcycle mileage race each year where the contestants have to maintain a typical highway speed on a road race track. Unlike most bikes that have little or no true aerodynamics these do. MPG at 60+ MPH is anywhere from 100 - as high as 470 MPG.

I have his CD where he stated that a typical motorcycle only needed 125 - 250 CC's and about 18 HP to be practical. Now think if you gave it 30 HP and a high efficiency engine on a truly streamlined shell what it would do on the street.

Remember stop and go is all about weight and cruise is about drag.