Mustang3GT07

+1 lol

batmobile2005

actually the amount of work is constant for any reaction, so time is the variable. in either motor trend or road and track they did this and said that they actually do get better gas milage so thats why i found this interesting considering that everyone else, including the instruction manual tells you to feather the gas. so wierd

drbobvs

Your theory is true for full hybrid vehicles, such as a Toyota Prius. The reason is electric motors operate at their peak efficiency at full throttle.Gas engines operate at peak efficiency at part throttle and cruise. It has been the practice of hybrid owners to do exactly as you say, go hard from the line up to cruise speed then let off. Since the electric motor operates from a stand still, and the gas enginekicks in at highway speeds. Therefore, you have already let the electric motor do most ofthe work, accelerating the vehicle.

This has been proven time and time again in these types of vehicles only. Sorry, but in your car, you'd be using more gas, not less.

Toad

There are way more variables involved than just accelerating the mass of the car. Consider how much power it takes to run your engine...ie how much power is used by the engine to run itself. A typical reciprocating engine uses more than half of its' own power output to run itself, meaning this is power you cannot use. If your engine puts out 300 Shaft horsepower, say, then it REALLY makes more than 600, but a little more than half of that is used to compress the intake mixture, move the valves, turn the crankshaft assembly, spin the water pump, etc. Picture try to turn your engine over at 6,000 rpm with an electric motor...it would take a HUGE motor.

So, the higher your RPMs, the more power is being created, but also the more power is being consumed by the engine itself.

There is also power loss due to heat conversion. The more heat that your engine puts out, the more fuel that is being wasted.

The most efficient algorythm for acceleration to cruise also must take into consideration the distance to be cruised. For example, if you're only going one city block, the most efficient speed will be very very slow. But if you're to travel 50 miles, and can cruise without stopping, you obviously need to reach a higher speed. Also remember that air resistance is squared every time speed is doubled. So the faster you reach cruising speed, the more air resistance you are overcoming. And at speeds above about 25 mph air resistance is the greatest usurper of power.

If you're using the onboard computer to determine your gas mileage in the comparisons, you'll need to use the entire leg and not just the acceleration part. I find it hard to believe that people say they see better mileage with "Jackrabbit" accelerations. But I really didn't buy my mustang for its' fuel economy.

Orion_240

oh, so all those warnings about how we should avoid jack-rabbit starts in order to save gas are incorrect???
For decades they've been telling us that, with plenty of statistics to back it up.
But somehow, you think you're going to stop when you hit the speedlimit! LOL!

brayson

+1 drbobvs and Toad.
to the op: basically the easiest way to think about it is that you need to get your car to a final speed of 60mph, and at this speed, your car has a kinetic energy given by
KE=.5*m*v^2 m= the mass of the car v= velocity.
Acceleration doesn't come into play. So basically, we need to add this amount of energy to the car to get to sixty, and it doesn't matter if we do it over 5 seconds or 50, it requires the same input. One poster said this.
It is true EXCEPT for the fact that our engines don't operate at the same efficiency at any given RPM, the amount that you waste increases. Ever notice how if you run your car very hard, you can feel the heat coming off of it? This heat doesn't come for free. Also you do all kinds of extra work by introducing weight transfers by lifting up the front end and squatting the rear when you hammer the throttle.
Basically, in this car, there is absolutely NO way to get good economy the way you are talking about.

[align=left] [/align]

Bmr4life

From first hand experience, it is better to slowly get to 60mph.

Try this test.

Reset the MPG meter and Trip Odometer.

First Test. Floor it to 60mph and cruise until trip ODO says 1 mile. Record MPG.

Reset the MPG meter and Trip Odometer again.

Second test. Cruise to 60mph and continue at 60mph until trip ODO says 1 mile. Compare MPG.

howarmat

no data = BS......... IMO

Bmr4life

I don't believe that either. If a Pruis floors it to 60mph, the gas motor will kick in immediately. If it cruises to 60mph, the gas motor won't kick in until 35mph or later. I have riden in my coworkers Prius and they can get around at 35mph without the gas motor turning on.

batmobile2005

oh absolutely, i agree. im sorry, i didnt mean for it to say that the only car variable is distance. solely in the physics equation for work, which is force times displacement (or distance), distance is the variable in this case, thats why physics should back it up. but physics never takes place in a single variable environment, so thats why other factors definitely take precedence over it. its an interesting notion, theoretically, and itd be hilarious if it worked, but under the conditions that i tested it in and even after hearing the reports, im still skeptical, like most everyone else here haha