100 mph & 32 mpg

[sheepdog 44]

Originally Posted by aerohead

That's really the point of the blog,to stimulate thinking and conversation.
We wouldn't be altering automotive technology,just how people think about it.

I think it would be best to do this using railroad wheels and tracks. Less than a tenth the rolling resistance, very minimal elevation change to facilitate a full length boat tail. It would be much safer as well (for them and everyone else), and it could be fenced in to eliminate potentially hitting an animal at 100mph.

Well, some would say it then it isn't a car, really, with the freedom of the open road. But then you could raise the limit to 150-200mph. Imagine cross country at super car speeds every second of the way.

[RedDevil]

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?

Sorry to come back on this again, but in my first post I missed the elephant in the room.

I like my car.
I really like my car.
It is the best car I've ever had - by a wide margin.
When I arrive home I sometimes just sit there, unwilling to get out. The wife and kids are good to me, don't blame them. But I hate to let go of my car.

Should I now rush to get where I'm going and spend as little time as possible in it?

I see all the other cars rush by at the motorway and think: Yeah, if someone forced me to drive that I'd hurry to get out too!

[aerohead]

Originally Posted by Xist

I was comparing 55 MPH and 100.

Okay,gotcha!
Yeah,we want to believe that linear thought,deductive reasoning,and perspicacity hasn't been completely bred out of N.America.
If you read between the streamlines you realize the potential gains from 'normal' operations from such a vehicle class.
'Economy' cars constituted less than 2% of total automotive sales and automakers must have thought 'well to --ll with them!'
Speed seems to remain sexy enough to garner attention.Vin Diesel is making a career out of it.
It's possible that 'performance' might be a carrot with which to establish the form in the market,then 'wannabe's' will want the 'form.'

[aerohead]

Originally Posted by sheepdog 44

I think it would be best to do this using railroad wheels and tracks. Less than a tenth the rolling resistance, very minimal elevation change to facilitate a full length boat tail. It would be much safer as well (for them and everyone else), and it could be fenced in to eliminate potentially hitting an animal at 100mph.

Well, some would say it then it isn't a car, really, with the freedom of the open road. But then you could raise the limit to 150-200mph. Imagine cross country at super car speeds every second of the way.

That's a whole 'nuther blog.And given time we'll take that on.( I do have some data on such things).
We have little confidence that folks can maintain attention if we bombard them with too many themes at once.So we're trying to stay on point.One blog at a time.

[robchalmers]

I'd actually like to try that in my Megane. I sit my car at 120kph (@only 2krpm) most days and I'm getting more than 48.... bone stock.

obviously the sq law rule will take its toll but If I got it across to germany I'd ben willing to give it a stab!

[ERTW]

a point to consider is that operating a gasoline engine closer to peak torque rpm at certain loads improves bsfc. l question the mpg predictions. 111 mpg at 55 mph seems optimistic.

better aero, along with good door seals, eliminates wind noise. lrr tires make less noise. and a large enough muffler quiets the ice. the high number of ratios in new transmissions are actually meant to keep engine rpm low for low noise and vibration - not much to do with fuel economy. running at peak torque - for best efficiency - negates the extra gears. engine noise will dominate at 100 mph. unless you get a torquey diesel that operates at 1300 rpm.

the 112 bhp opel eco speedster got 113 mpg at 140 mph!

[jamesqf]

Originally Posted by Vekke

Do you people who like to drive slow put any value to your free time...

I value my free time, it's just that I don't save a great deal of time by e.g. going 85 rather than 65 on the freeway. Back in my commuting days, I'd have saved far more time by having a reserved parking spot right outside the lab, or having all the traffic signals on my route synchronized.

PS: Granted that it takes a bit of a tailwind to get the Insight up to 100 mph, but IIRC I was getting about 30 mpg at that speed. And there are a couple of places locally where I can hit about 85 while coasting :-)

[101Volts]

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?

It depends on the trip but I do value my Father having a low car insurance rate since I'm 22 years old at this time; I also don't like the thought of going between 60 and 65 where people ganged up on me in a pack, I'd rather go between 55 and 60 so other cars will not be around the vehicle I drive much (Most people passed if I was doing that)

[Xist]

Originally Posted by jamesqf

PS: Granted that it takes a bit of a tailwind to get the Insight up to 100 mph, but IIRC I was getting about 30 mpg at that speed. And there are a couple of places locally where I can hit about 85 while coasting :-)

Is that MPH or MPG?

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.

However, it was enough for me to coast back up the other side.

[aerohead]

Originally Posted by ERTW

a point to consider is that operating a gasoline engine closer to peak torque rpm at certain loads improves bsfc. l question the mpg predictions. 111 mpg at 55 mph seems optimistic.

better aero, along with good door seals, eliminates wind noise. lrr tires make less noise. and a large enough muffler quiets the ice. the high number of ratios in new transmissions are actually meant to keep engine rpm low for low noise and vibration - not much to do with fuel economy. running at peak torque - for best efficiency - negates the extra gears. engine noise will dominate at 100 mph. unless you get a torquey diesel that operates at 1300 rpm.

the 112 bhp opel eco speedster got 113 mpg at 140 mph!

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.
When the 3-Musketeers streamlined the DeSoto Airflow,they used a constant BSFC to dial in the gearing to maximize mpg.
The 1977 VW 'Safety' Rabbit @ Cd 0.125 would have seen 93+ mpg at 56 mph,up from 68 mpg.
I think that the Cd 0.195,1978 M-B C-111 III attained 17 mpg at 225 mph.
The 1982 VW ARVW got 39 mpg at 155 mph.
I would certainly like to verify the claims,but until then must rely on SAE prediction tools.
PS I ran the numbers for the 2013 VW XL1.With the 1996 Honda gasoline technology,the VW would see about 46 mpg at 100 mph.
If it were increased in frontal area from 1.5m-sq (16.14 sq-ft) to accommodate 4-5 passengers it would require more horsepower to sustain 100 mph.