Craig Vetter Quote...

[PeterS]

Drag reduction ands gearing are the key to high fuel efficiency .Riding technique can help but nothing like not pushing vast amounts of air around .

Put any set of specs in here check then halve the cD and look again .
Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com

[dcb]

Originally Posted by PeterS

Drag reduction ands gearing are the key to high fuel efficiency

That is a highway only perspective, that isn't how we all drive, at least not predominantly. In the city (where most of us spend much of our lives) it is mostly about technique (accelerate efficiently, don't overdo it so you have to brake, don't use your engine if you don't have to), and weight, especially from a "make the most of what you have" perspective.

the AERO HP in that calculator at 25mph is 1.7, at 70mph it is 18.57, over 10 times more. Where rolling resistance went from .98 to 2.73. The benefits of aero are a function of speed, and can make parallel parking a b$tch.

This isn't THAT complicated. I'm not saying Craig should change the contest, just the rhetoric.

[Frank Lee]

Perhaps Craig isn't condemning hypermiling tactics IN GENERAL; he just doesn't want them in his competition which makes sense because many hypermiling techniques are not ever going to become mainstream i.e. widely adopted. He's been down the "fringe element" road many more times already than anyone else here.

[jkv357]

A question for Craig -

How did you pick 70 MPH as a requirement?

Seems like the speed limit couldn't be that high on the stretch of road where the challenge was held. I would think cruising at 55 MPH, especially in those conditions (strong headwinds), would be an adequate and realistic test.

If a person is looking to maximize mileage, the last thing they would want to do is travel faster than is required - or legal.


Jay

[pletby]

Originally Posted by jkv357

A question for Craig -

How did you pick 70 MPH as a requirement?

Seems like the speed limit couldn't be that high on the stretch of road where the challenge was held. I would think cruising at 55 MPH, especially in those conditions (strong headwinds), would be an adequate and realistic test.

If a person is looking to maximize mileage, the last thing they would want to do is travel faster than is required - or legal.


Jay

Hey Jay, how goes? Seems when I pass through your State every 3 months it's the one with the slowest speed limit (65 if I remember?) I encounter. 70 to 75 being the norm. Guess what? When I'm doing that speed limit in other faster States I'm the slow one. I think it's pretty darn realistic for the average American Interstate.

The average American (or Canadian for that matter) will not be looking to maximize mileage until things get much worse than they are. They'll be most concerned with how long it'll take them to get home after work, and how comfortable they are. They'll fill their blue box for recycling and pat themselves on the back for how eco friendly they are. I hope I'm wrong.

[cvetter]

I think I see the problem here.

We seem to have different goals.

As a nation, we in the USA are importing 3 out of every 4 gallons of petroleum that we consume in transportation. My goal as a designer is to help us to live better on less energy. How much less energy? Why, 75% less energy, of course. My particular interest is in 2-wheelers, which typically get less than 40 mpg in published road tests. My goal then is to help us ride better and get 120 mpg.

For me living better means 120 mpg any time, all the time. It means riding in even more comfort. It is being able to carry a more useful load. It means developing a vehicle that is so attractive that we will really want to use it. It means a stronger USA because we are living within our budget of energy.

I don’t want to change my driving style to accomplish these goals. I want change my design. To do both simultaneously introduces too many variables.

I will leave the driving techniques to you.

If I cannot do this with innovative designs, I will look to you hypermodders to complete the job. Until then, I like going the posted speed limit which is 70 on freeways in California. I like out-accelerating most cars. I like the kind of machine I am developing. It is really my first choice.

Craig

[user removed]

Why should it be a problem? I have driven a car in traffic here at 65 MPH and 84 MPG.
Heavy congested Interstate traffic from Williamsburg to Hampton Va. The posted speed limit on that route started at 65 MPH and as you get closer to Hampton it drops to 6o, then 55. At the Hampton Roads bridge Tunnel 94,000 cars enter the two lane tunnel in each direction every day. Not much more congestion anywhere in the USA. That's an average of a car less than two seconds apart 24-7.

P&G there and your life expectancy just dropped, period.

I am not against hypermiling, and many here may curse me for saying this, but I truly believe that there is a better solution here right now. Aero is certainly a part of it, in fact a major part, but of equal importance it to maintain the engine operating at best BSFC regardless of vehicle speed, with speeds consistent with traffic flow.

If your situation permits and your overwhelming desire is to minimise fuel use then drive at an average speed of 15-25 MPH. Most cars can get 80 MPG at that speed. The first car I actively hypermiled, a 91 Civic Hatch would do close to 100, as would my 2002 Insight.

Now if you tried that on I64, you would probably be pulled over and cited or assaulted with various objects in very short order.

Hypermiling has made me a much better driver and more efficient, but I share Craig's feelings, which happen to mirror those of Basjoos that I want to drive roads at the speed limit they were designed on which to be driven.

When I picked up my 2011 Honda CBR250R, I drove 860 miles in 18 hours total time, stopped to fill the tank several times, to eat several times, and to buy, load up and haul the bike 430 miles back home. From 11:15AM Wednesday to 5:45 AM Thursday I was on the road, without rest and averaged 70 MPH 90% of the time and 20 MPG, in a 19 year old truck that was originally rated at 19 on the highway on E10 fuel.

When Eisenhower came back from Germany in 1945, he was impressed with the Autobahns and their strategic usefulness. The Interstates were engineered for 70 MPH speeds, when cars were deathtraps.

regards
Mech

[redyaris]

On my way to the Vetter Challenge in Carmel Ca. next year I will be hypermiling all the way. In doing so I will be the 1 in 100,000 motorists who is doing that. I will probably be getting close to 100mpg hypermiling. While running the Vetter Challenge I wil probably be getting 80mpg, without hypermiling, which is 20% below what hypermilling would get. We all know that driving style is worth 20% - 25% in fuel economy.
I can find no reason to take offence at what Craig has said, its his rules for his challange... I will at some other time go to an all out hypermiling event to see what I can achieve. For those interested in other contest please see Events & Meet Ups.

[jkv357]

So the challenge is run on open highways with a 70 MPH speed limit then?

Seriously, is that the case? Because it didn't appear that way to me.


Jay

[PeterS]

Originally Posted by dcb

That is a highway only perspective, that isn't how we all drive, at least not predominantly. In the city (where most of us spend much of our lives) it is mostly about technique (accelerate efficiently, don't overdo it so you have to brake, don't use your engine if you don't have to), and weight, especially from a "make the most of what you have" perspective.

the AERO HP in that calculator at 25mph is 1.7, at 70mph it is 18.57, over 10 times more. Where rolling resistance went from .98 to 2.73. The benefits of aero are a function of speed, and can make parallel parking a b$tch.

This isn't THAT complicated. I'm not saying Craig should change the contest, just the rhetoric.

Well ,seeing the thread is about Craig's challenge I can only repeat that if 70mph and 120 mpg are the goals very good aerofairings are the only way .Big engines give the 70mph easily but at 70 mph a bike with a cD of .75 is using 20hp and getting 45mpg .
Lower the cD to .35 with the same fA and the same bike gets 90mpg and uses 7hp to stay there .That leaves a lot left over for acceleration and climbing hills .

Aero drag is everything !