" Aerodynamics doesn't begin to have an effect until 60 MPH "

[bandit86]

Originally Posted by vadimr4

When I hear people say that aero doesn't come into play until 30 or 40 mph haven't ridden a bicycle recently. On a bike, even 10 to 15 mph you can feel a difference if you are tucked in or sitting straight up.

I think what they mean to say is that as far as total energy input to distance gained or traveled, aerodynamics don't play as in significant as higher speed. Your car could get 200 miles per gallon if you're traveling 8 miles an hour but it is not really reasonable

[racprops]

Originally Posted by bandit86

I think what they mean to say is that as far as total energy input to distance gained or traveled, aerodynamics don't play as in significant as higher speed. Your car could get 200 miles per gallon if you're traveling 8 miles an hour but it is not really reasonable

There is this:
The Shell Oil 1973 Test Car
376 miles per Gallon

0,625 liter/100 Km 1 liter/160 Km

You can read about it here: Shell Opel

As you said "200 miles per gallon if you're traveling 8 miles an hour but it is not really reasonable"

This was a extreme test, the car was highly modified to go just about 30MPH ONLY, and it took a bit of time to get to that speed with a over heated engine rigged to run off a small lawn mower/ or small motor cycle carb.

And this test was a flying start, that is it hit the traps running at speed and only for a short mile or two miles for the test and I think some nypermileing or coursing was involved.


I am surprised they did not find a high hill and let it idle as it roller downhill.


It was a totally undriveable car in any real world.


BUT THIS one was a real world stock cars and they were driven on real roads test:

An English TV show Top Gear Series 12 Ep. 4 Summary: This week's challenge is to drive from Basel in Switzerland, to the north west coast of England. This must be done on just one tank of petrol - no splashing and dashing in France, just one tank. The first to arrive - if any do - gets the honor of switching on Blackpool's illuminations. Some 740 Miles. Air Date: November 23, 2008

So one car is a Volkswagen Polo Blue Motion, a Diesel 3 cylinder that is rated at 75MPG!!!!! and has a 10 Gal. tank driven by Richard Hammond. The second car driven by James May was a Subaru Legacy diesel rated at 50MPG and has a larger tank lastly. Jeremy Clarkson shows up with a Jaguar XJ diesel, this is a full sized car with four doors etc. His plan was to run out of gas near London and thus go home, it was rated at 35MPG.

What happened?? First ALL three cars made the 740 Mile trip!!! What is even more insane was at the end of this show Jeremy Clarkson whom did NOT drive sanely until he had passed London was very surprised the Jag made it but wait there is more, he reported the shows engineers checked how much gas was left in the tank and reported that the Jag could have gone 260 Miles MORE that meant the Jag had a range of 1000 MILE per tank.

Point of Order: The UK Gallon is not the same as the US Gallon, so a little calculation shows that would ONLY be around 850 MILES per a tank in US Gallons of gasoline.

By the way none of these cars had any areo done to them.

From what I have read right here on this very site AREO is only worth a few MPG even in the extreme, as in removing side mirrors, windshield wipers, door handles, rain gutters, roof racks, then adding under belly pan, rear wheel fender skirts, if possible front fender skirts if not then large disk like wheel covers, and lastly insane Boat Tails.

And after all that you might gain 5 MPG.

So check out the current Big Rigs, ground effects, a curved air defectors on the cars to push air up over the boxes and the boxes with some under belly deflectors.

That is it. Truckers will fight to gain even .05% more MPG.

And that is as far as they have gone.

Rich

[freebeard]

All that was proven was that 'one tankful' is not a standard for measurement.

From what I have read right here on this very site AREO is only worth a few MPG even in the extreme, as in ....stuff.

I'm hoping someone refutes this, I'm being driven from my home by lack of groceries.

Maybe start with Aerocivic, and the rule of thumb first order approximation that 0.1 delta in Cd is worth some number of MPG.

[racprops]

Well watch this thread: OK Bottom line, what real MPG can you get??

https://ecomodder.com/forum/showthre...tml#post661848

I was kind of disappointed when I learned how little all that stuff could do.

Rich

[Piwoslaw]

Originally Posted by racprops

From what I have read right here on this very site AREO is only worth a few MPG even in the extreme, as in [...]

And after all that you might gain 5 MPG.

Is this statement in general, or for that specific Top Gear scenerio?

Because all that Top Gear proved was that less efficient cars have larger tanks, so that different cars have similar ranges. Or actually, it just proved that 3 people, driving 3 cars, were able to drive between 2 cities without refuelling.

In general, aero is very important, even in city driving. My results with short Kammback (not a long boattail) gave ~7% improvement. Measured not with a butt-o-meter, but by A-B-A testing in the best controlled conditions as possible. I used a mere fraction of the fuel the Top Gear team used (wasted - if you count in the cost of transporting the cars before/after the test, the vehicles of the camera teams, etc.) but received more tangible results.

But the bare numbers of aero only do not show the whole picture. Again, from my experience - Hypermiling alone would give me maybe 20%, aero alone 7-8%, but together I saw around 40% improvement. Why? Because the improved aero allowed me to not only get more out of the hypermiling tricks I already used with the car before aero, but also allowed to use certain tricks which were not worth while in the stock car.

And a lot of this was in city driving, with traffic and speeds rarely exceeding 50 km/h. The very first benefits I observed with the new Kammback was not on the highway, but was the extended coasting between intersections. This really surprised me and showed me the importance of aero at low speeds.

[freebeard]

You can only get so far with half-measures.

[racprops]

First Nice car.

Second:

My problem is a areo, hypermiling tenchniques, a lean burn Engine, and I bet a few other MPG tricks.

So it does not answer my main question: With Aerodynamics alone in a normally driven car with no hypermiling tenchniques or any other MPG Tricks what will you get??

I want to take long road trips and do NOT want to use hypermiling tenchniques, I want to just set cruse control and go.

Rich

[freebeard]

How about this?

So it does not answer my main question: With Aerodynamics alone in a normally driven car with no hypermiling tenchniques or any other MPG Tricks what will you get??

I want to take long road trips and do NOT want to use hypermiling tenchniques, I want to just set cruse control and go.

Your Mileage May Vary. Standard disclaimer.



http://www.explainxkcd.com/wiki/inde...ding_Variables

The other thread suggests you know what it would take to answer the question. I might ask what effect aero aids would have on driver fatigue over long distances.

[Isaac Zachary]

Originally Posted by racprops

First Nice car.

Second:

My problem is a areo, hypermiling tenchniques, a lean burn Engine, and I bet a few other MPG tricks.

So it does not answer my main question: With Aerodynamics alone in a normally driven car with no hypermiling tenchniques or any other MPG Tricks what will you get??

I want to take long road trips and do NOT want to use hypermiling tenchniques, I want to just set cruse control and go.

Rich

You will get better fuel mileage, but only to a certain degree.

Your engine will need to produce less power, so will use less fuel. But it will be less efficient at making the power it does produce, so it's not like if you half your total drag you'll double your fuel economy.

[aerohead]

Originally Posted by racprops

There is this:
The Shell Oil 1973 Test Car
376 miles per Gallon

0,625 liter/100 Km 1 liter/160 Km

You can read about it here: Shell Opel

As you said "200 miles per gallon if you're traveling 8 miles an hour but it is not really reasonable"

This was a extreme test, the car was highly modified to go just about 30MPH ONLY, and it took a bit of time to get to that speed with a over heated engine rigged to run off a small lawn mower/ or small motor cycle carb.

And this test was a flying start, that is it hit the traps running at speed and only for a short mile or two miles for the test and I think some nypermileing or coursing was involved.


I am surprised they did not find a high hill and let it idle as it roller downhill.


It was a totally undriveable car in any real world.


BUT THIS one was a real world stock cars and they were driven on real roads test:

An English TV show Top Gear Series 12 Ep. 4 Summary: This week's challenge is to drive from Basel in Switzerland, to the north west coast of England. This must be done on just one tank of petrol - no splashing and dashing in France, just one tank. The first to arrive - if any do - gets the honor of switching on Blackpool's illuminations. Some 740 Miles. Air Date: November 23, 2008

So one car is a Volkswagen Polo Blue Motion, a Diesel 3 cylinder that is rated at 75MPG!!!!! and has a 10 Gal. tank driven by Richard Hammond. The second car driven by James May was a Subaru Legacy diesel rated at 50MPG and has a larger tank lastly. Jeremy Clarkson shows up with a Jaguar XJ diesel, this is a full sized car with four doors etc. His plan was to run out of gas near London and thus go home, it was rated at 35MPG.

What happened?? First ALL three cars made the 740 Mile trip!!! What is even more insane was at the end of this show Jeremy Clarkson whom did NOT drive sanely until he had passed London was very surprised the Jag made it but wait there is more, he reported the shows engineers checked how much gas was left in the tank and reported that the Jag could have gone 260 Miles MORE that meant the Jag had a range of 1000 MILE per tank.

Point of Order: The UK Gallon is not the same as the US Gallon, so a little calculation shows that would ONLY be around 850 MILES per a tank in US Gallons of gasoline.

By the way none of these cars had any areo done to them.

From what I have read right here on this very site AREO is only worth a few MPG even in the extreme, as in removing side mirrors, windshield wipers, door handles, rain gutters, roof racks, then adding under belly pan, rear wheel fender skirts, if possible front fender skirts if not then large disk like wheel covers, and lastly insane Boat Tails.

And after all that you might gain 5 MPG.

So check out the current Big Rigs, ground effects, a curved air defectors on the cars to push air up over the boxes and the boxes with some under belly deflectors.

That is it. Truckers will fight to gain even .05% more MPG.

And that is as far as they have gone.

Rich

On three road trips Spirit has returned just under 40-mpg, on a truck which originally saw 26.4 mpg at the same velocity. Only the shape was modified.