Top MPG on website - does % above EPA make more sense?

[larrydag]

I like the top MPG rankings on the website. But that is obviously skewed toward super efficient vehicles. I would love to see a ranking of % above EPA rating. I bet we would be surprised to see who would be in the Top 10 on that list. I guess that is more of a Hypermiler rating than anything but none of the less would be neat to see.

[PaleMelanesian]

Would it be difficult to just make the %epa column sortable, just like the others?

[Daox]

What happens if your vehicle isn't EPA rated?

I don't really care either way, but I'll throw it out there.

[PaleMelanesian]

True. It's not ideal. But the column is there, so why not use it as it is?

[MetroMPG]

Larrydag: good points. The intention is to develop the garage much more extensively, with multiple lists (people love lists) by vehicle type, absolute & % over EPA values. There are a few more ideas bubbling away on top of those.

PM: the reason it's not sortable by % over EPA is because it's calculated dynamically as the page is spat out. I'd need to make that a db column, or do the EPA calc during the query - and ultimately one of those is the goal.

But before I do that, the next thing I was going to add is for the many cyclists on the forum: a 'cycle log' for calculating distance traveled in the current year as % driven vs. % ridden, that generates a sig image with a "progress bar" in it.

After that, more time developing the garage. There's a lot of neat stuff that can be done in there.

[PaleMelanesian]

It's all good. You're a busy man, I'm sure.

[Peakster]

Originally Posted by MetroMPG

But before I do that, the next thing I was going to add is for the many cyclists on the forum: a 'cycle log' for calculating distance traveled in the current year as % driven vs. % ridden, that generates a sig image with a "progress bar" in it.

Woo! Finally

[Nerys]

I am curious just how efficient cycling is. Clearly its far more efficient than a car even an EV but HOW efficient? IE could the average not in the greatest shape person pedal to 45mph say if they had an aeroshell? I can sustain 25mph on my mountain bike for a few minutes before wearing out a bit but I also reach the limit of my gearing IE I can not pedal any faster but I know I have more go juice left.

I know a trained athlete can do it but what about average joe who puts some effort into it. I am thinking a small EV motor to boost up hills but I could not carry enough power for sustained EV usage so it would have to be for hills only.

Going to work would not work but it might be neat for getting around locally!!

[Lazarus]

Originally Posted by Nerys

I
Going to work would not work but it might be neat for getting around locally!!

Why?

[Andyman]

I have an old Bicycling magazine that has a graph showing power vs speed for a 10 speed bike. The name of the article was "What Effects Bicycle Speed?". If the author had used good grammer he would have used the word "Affects". The graph shows that you need about 0.16 HP to go 15 MPH and 0.25 HP to go 20 MPH. I think that 30 MPH required about 0.9 HP. A physically fit person can make 0.25 horsepower for several hours. One horsepower is about the limit a person can do for a quick burst of speed for 10 seconds or so. A one horsepower motor would really speed up hill climbing.

Lets say we have a hill with a grade of 10% and a bicycle and rider weighing 200 lb. The grade is the tangent of the hill angle (rise/run). The sine of the angle determines the force to be overcome by the motor and this is almost the same as the tangent for small grades so the force is about 200 lb * 10% = 20 lb.

V=375*P/F

so if F=20 lb. and P=1 HP

V=375*1/20
V=18.75 MPH

You could climb the hill at 18.75 MPH if there were no other drag forces.

If you had a gasoline engine with reasonable efficiency (0.5 lb/HP*Hr) connected to the bike using 0.25 HP and going 20 MPH on level ground, we can calculate the MPG.

MPG=D*V/(BSFC*P)

The density (D) of gasoline is around 6.25 lb./gal

MPG=6.25 LB/GAL * 20 MPH / (0.5 lb/HP*hr * 0.25 HP)
MPG=125/0.125
MPG=1000

So we can get 1000 MPG on a motorized bicycle if the speed is limited to 20 MPH and gear ratio and displacement are correct. A 12 cc engine running at 2500 RPM would be about right. Even better economy can be achieved with some aerodynamic improvements to the bike.