100 mph & 32 mpg

[jamesqf]

Originally Posted by Xist

Is that MPH or MPG?

MPH. MPG of course is infinite when I'm coasting (at least in warmish weather), since the engine is in DFCO.

I once hit 100 MPH coasting as I drove to my parents' house. Now I engine brake to sixty-five, and the idea of hitting a hundred through a canyon appalls me.

I understand. There are quite a few places where I could probably top 85 mph, maybe 100, while coasting, if it wasn't for the curves - and things like deer, possible lurking cops, etc.

[Xist]

Originally Posted by jamesqf

MPH. MPG of course is infinite when I'm coasting (at least in warmish weather), since the engine is in DFCO.

I wish that mine did that! According to the Forester forums, that is supposed to happen somewhere around 2,000 RPM, which I think is absurd. Except for canyon driving, I never maintain that speed without my foot on the accelerator!

I have seen momentary MPG of a few hundred many times. Coasting downhill in-gear, I have great MPG, but I have never seen the legendary series of nines, and it always shows a positive GPM. I am pretty sure that it actually increases if I downshift downhill.

I understand. There are quite a few places where I could probably top 85 mph, maybe 100, while coasting, if it wasn't for the curves - and things like deer, possible lurking cops, etc.

All of my good hills have curves, I hit an elk, and I have been pulled over multiple times.

After years of driving one way to my parents' house, for some reason I drove the other, and realized that it was shorter and faster. That canyon was even crazier, my GPS showed dozens of switchbacks! The speed limit was 35 MPH, too, compared to 55+ the other way, but it was still faster.

I asked my dad why he did not drive that way and he said that he kept getting pulled over.

[arcosine]

My saturn would get about 32 mpg at 100 mpg, since it gets 50 mpg at 65 mph.

[101Volts]

Originally Posted by arcosine

My saturn would get about 32 mpg at 100 mpg, since it gets 50 mpg at 65 mph.

What do you mean?

[8307c4]

These articles assume the reader is stupid and thus fails to realize that if a car that is doing 100 mph can in fact get 32 mpg's that said car would most likely top 50-60 mpg's at a more reasonable speed.

But you want to kill yourself, that's entirely your choice, please keep yourself and your vehicles off my highways so long you are a danger to yourself, my life, my safety, and the lives and safety of others.

Originally Posted by arcosine

My saturn would get about 32 mpg at 100 mpg, since it gets 50 mpg at 65 mph.

Case in point.

[Xist]

Originally Posted by 8307c4

These articles assume the reader is stupid and thus fails to realize that if a car that is doing 100 mph can in fact get 32 mpg's that said car would most likely top 50-60 mpg's at a more reasonable speed.

But you want to kill yourself, that's entirely your choice, please keep yourself and your vehicles off my highways so long you are a danger to yourself, my life, my safety, and the lives and safety of others.

People care more about texting at 100 MPH than getting 32 MPG.

[ERTW]

Originally Posted by aerohead

For the 55 mph numbers I just used what Honda had published for their 'conventional' car,and taking the R-R power directly off the curve and calculating the aerodynamic road load HP for the new CdA,I got the new 55 mph road load.Then using the Honda's 0.448 lbs per brake horsepower-hour BSFC and a simplified 6-lbs/gallon,it spit out 111 mpg allowing for the Chrysler/Gino Sovran/Wolf Hucho gear-matching.

my thinking is: you run a car at a certain speed, a certain rpm, and load (which determines bsfc). reducing aero load simply gives the same load at a higher speed - with the same rpm and load on the engine (with appropriate gearing). so your 32 mpg at 100 mph is not the issue.

mechanical friction increases with the square of the speed. Reduced wind drag means mechanical friction is the significant loss to accordingly higher speeds. Wind drag increases with the cube of the speed, so there is a definite benefit to higher speed/lower drag.

I'm interested in seeing those SAE standards. I was under the impression that the fuel economy curve is an inverted bathtub...so at best l'd expect the plateau to extend higher...not climb drastically as you state.

Now you'll have to police drivers without appropriate licenses - and more importantly, the necessary skill to handle the car. how many new licenses will it take before the state drops millions of dollars to build a special lane? How do you police drivers from out of state? Driver training would have to be raised in the entire north america (way too low a standard). Germany's standards seem appropriate - 18+, $3000, graduated licensing, yearly car inspections, regular recert, know how to change your oil, etc).

[Xist]

When I lived in D.C., people would go there from other states when they could not pass their driver's license test; you would need higher standards everywhere, but you would need for them to be consistent.

[Frank Lee]

Originally Posted by Vekke
Do you people who like to drive slow put any value to your free time or are you just trying to save the planet by saving fuel (less co2) and its OK sacrifice to spend some 20-81% more time in your car?

I rarely drive at all in my daily routine, so my driving is largely limited to longer x-country trips thus I spend A LOT less time in cars than the average bear. Those long trips are really the only sort of trip that benefits from higher speeds but I plod along because it saves fuel and it saves money. I don't mind the slight time penalty as I plan my departure time and pace such that arriving on time is easily assured, even when I make stops along the way for fun.

I'm going to argue that those who are always driving- no matter the speed- are the ones that don't value their time because for whatever reason they arranged their lives around the notion of tearing all over the place.

[320touring]

The real question should be more fundamental

"Why does modern life need us to be this fast?"

tele commuting would allow better communities (more folks able to use local services/shops as they're about when they are open) with a reduction in fuel consumption, and a corresponding drop in traffic density.

32us MPG at 100mph is a noble goal, but opens more issues than it solves (e.g. acceptance of radical aero designed cars (needed for the Cd's refered to in the blog) and also the issues surrounding energy transference at that sort of speed, should the worst happen)

good on you for getting the thinking going though- some good ideas in the blog and on this thread