"CAR_IS_MI" (car-is-mi)
11/07/2013 at 17:19 • Filed to: Horsepower, rant
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"CAR_IS_MI" (car-is-mi)
11/07/2013 at 17:19 • Filed to: Horsepower, rant | 2
| 20 |
What is Horsepower, and why do I care?
Horsepower is a term used to describe an output of force where one horsepower equals 746 watts, or, in mechanical equivalents, one horsepower = 550 ft/lbs per second.
The term was originally created to compare the output of a steam engine to that of horses (as if to say, this steam engine can plow your field in the same manner as two horses, or, this steam engine has a two horse power output.)
At the time of the invention of steam, and later, gas powered horseless carriages, this number became of value. A carriage drawn by four horses had the ability to move more weight, more efficiently than a single horse carriage. In the same thought, a four horsepower engine can move more weight, more efficiently than a one horsepower engine.
To better understand horsepower we have to go back to the fact that 1 horsepower (in mechanical terms) is equal to 550 foot - pounds per second. This is not to be confused with torque, which is read as pound-feet. Foot-pounds (ft/lbs) is a measurement of the energy that is transferred when one pound-force is applied through a displacement of one foot.
Did I lose you there?
In other words, one horsepower is a force exertion of 550 ft/lbs per second on an object with a mass of one pound at the earths surface being moved one foot.
Okay, so now that all the technical mumbo-jumbo that still has you scratching your head is out of the way; Why does horsepower no longer matter?
Well, it still matters, however, modern engines have been able to produce more than ample horsepower required to move the weight of cars and that of your 'average' American family since the mid 1970's.
Can a car still 'feel' under-powered? Yes, and here is why.
Vehicles built prior to 1972 (and sold in North America) were sold and measured using the SAE correction to Brake HorsePower (BHP). This is the output of an engine at the crankshaft, before any losses are incurred via the alternator, water pump, or any other accessories driven off the crank. This means that your engine advertised at 100 bhp, once in the car, would experience a loss of power due to driven accessories. Now it has an output of (hypothetically) 90 horsepower. Next, we connect this engine to a transmission filled with rotational parts witch require energy (horsepower) to move. By the time the power gets to the wheels, we now have a horsepower output of 65 hp.
In 1972, this standard was changed. While horsepower is still measured at the engines crank, it is now measured with all of the driven accessories attached, this leaves the only losses to be found from the gearbox back. Now, your advertised 100 hp engine after losses puts out 88 hp to the wheels.
With advances in modern technologies, drivetrain losses are minimal percentages, add into the fact that ultra-light composites are more readily available and its simple to see that the amount of horsepower required to move a car is well exceeded.
The fact that your average soccer mom van is approaching the 300 hp mark is absurd, you can buy a street legal Mustang with 850 hp for under $100,000, and there are a handful of cars available (presuming you have the coin) with over 1,000 hp which can be driven on the roads. Legally.
Yet still, everyone wants to know "How much horsepower does it have?"
And every review reads "The new Ostentatious Family Cruiser has 450 horsepower!!!"
I don't care about horsepower anymore, and neither should you. Sure, it is a good marker, but in a normal daily driver, I know I will always have enough to get where I'm going. And in a performance car, I'd rather read about how the engineers spent countless hours making the suspension better, or the aerodynamics, as these now play more into the overall performance that that one number does.
The horsepower game is dead, over, we beat it. And no point in beating a dead horse...
Soon we will be at the point (if we are not already there) where the power outputs are too much. Lets shift the focus to things that actually make a difference now.
Someone Else's Projects
> CAR_IS_MI
11/07/2013 at 17:21 |
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Wait, wha? "Adjective"?
Nibby
> CAR_IS_MI
11/07/2013 at 17:24 |
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Pro-tip: Add stickers to your car for more horsepower!!!111oneoneoneleven
RamblinRover Luxury-Yacht
> CAR_IS_MI
11/07/2013 at 17:26 |
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Frequently, me likey torque > ultimate horsies.
Casper
> CAR_IS_MI
11/07/2013 at 17:30 |
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Sorry, you lost me when you asked me if I was "loose" or not yet. I need a few more drinks first.
You could also try just posting the equation so people understand the relation between torque and horsepower: HP=(RPM * T) / 5252.
Lumpy44, Proprietor Of Fine Gif
> CAR_IS_MI
11/07/2013 at 17:30 |
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I have always like HP compared to weight more than just HP alone. I feel it tells way more about the car.
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CAR_IS_MI
> Casper
11/07/2013 at 17:36 |
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Thanks boss man, never drink and type. Not that I'm drinking, I'm actually 'working', but same thing...
Also, then I would have to explain torque...
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CAR_IS_MI
> Lumpy44, Proprietor Of Fine Gif
11/07/2013 at 17:37 |
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Definitely a better comparison than straight HP.
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CAR_IS_MI
> Someone Else's Projects
11/07/2013 at 17:38 |
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Is an adjective not a descriptive word????
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Casper
> Lumpy44, Proprietor Of Fine Gif
11/07/2013 at 17:41 |
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Yep. For instance an old car in the 70s may only have had 150HP, but also only weighed in the mid 2000 lb range. Modern cars now weigh over 3000lbs on average. That means they need 30% - 50% more brakes, more power, and much more advanced suspensions to do the same work of an older car. At the end of the day, they will still be at a permanent deficit due to the weight.
The most important statistic is weight as it impacts every other statistical requirement.
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CAR_IS_MI
> Someone Else's Projects
11/07/2013 at 17:41 |
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"Words that describe people, places and things are called adjectives."
Horsepower is a thing, a non-tangible thing, but a thing...
(also, I'm not an English major, I actually am the exact opposite, an English flunkie)
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Casper
> CAR_IS_MI
11/07/2013 at 17:42 |
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I couldn't pass up the opportunity to jab you about that one ;)
Velocity- Peuguette Connoisseur
> Casper
11/07/2013 at 17:46 |
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unless you're driving a merican boat of a car from the 70s, then you have something that has a 8.3 liter v8 making 150hp trying to move a car that weighs 6000lbs
KillerRaccoon - Group J's Sébastien Loeb
> Someone Else's Projects
11/07/2013 at 17:46 |
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Horsepower is a unit of measurement and thus a noun, just like a meter or a second.
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Someone Else's Projects
> CAR_IS_MI
11/07/2013 at 17:46 |
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Words that define (as opposed to describe) things, even intangible things, are nouns. If you'd said "high horsepower", then "high" is the adjective. I'm no English major either, just a recovering grammar fascist.
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CAR_IS_MI
> Someone Else's Projects
11/07/2013 at 17:50 |
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because horsepower is the thing..
I get it (until I forget again).
Thanks former Grammar Nazi!
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Casper
> Velocity- Peuguette Connoisseur
11/07/2013 at 17:51 |
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True. I was more thinking of the performance cars that might be comparable to cars today. There were a whole run of American v8's that produced amazingly little power for the size... but that goes back to torque in relation to HP. Most of the time it was due to the low number of revs, not a low amount of torque. That's why they could still move small houses with such low HP... they just didn't move in a hurry.
911e46z06
> CAR_IS_MI
11/07/2013 at 18:14 |
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Horsepower = Top Speed
Torque = Acceleration
That's all I know about it, and it's probably wrong
Bruno Martini
> CAR_IS_MI
11/08/2013 at 12:46 |
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My car makes 307kw... Is that better? Personally I like knowing what the expected output of a particular engine is. The fact of the matter a famaily sedan has around 300hp means squat as it now weighs in at 4500lb. Having ample power is relative, I am sure I could get by with about 60hp day in and out, but I pay premium to have that 400+ hp engine under my hood. At the end of the day, its what you get used to. Talk to a typical trucker, they think a 100hp engine is overpowered for comuting, they are right. However not one of them has given up the change to have more of it. HP war is not over, not by a long shot. I expect to see 1000+ hp cars under 100K equivalent due to inflation over the next few years. 500hp will become standard fare soon enough for cars between 35-50k...
xx45xx
> CAR_IS_MI
11/13/2013 at 14:54 |
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the horsepower wars are back in full swing in the USA, we dont have "too much power" whats gonna happen is the EPA is gonna mandate higher and higher mpgs and lower emissions until these outputs are no longer feasible.
HugePanic
> 911e46z06
11/13/2013 at 16:32 |
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My car is the exact opposite of that. No torque due to 1.8l 4L engine, but "good" acceleration....
For the topspead you have to take the frontal area plus the drag coefficient into account.
For acceleration you have to respect the given weight....