Actually I did this to put things in perspective,I know that I HP is equivalent to 746 watts.I did this to illustrate the largely ignored power of the Sun,When equipment becomes a little better and the storage too, then people will realize we dont have to be slaves to the oil Barons.
When it comes to power needed to climb hills on a bike, horsepower is indeed the more convenient unit because you already know your weight in pounds and most distances are measured in feet.
Calculating power needed to accelerate is where KW is easier, provided you know your mass in kilograms and your speed in meters per second, simply because the kilogram is a proper mass unit, not a weight unit.
The pound is a force or weight unit, not a unit of mass. Since weight is mass times gravity, you have to divide your weight by whatever the acceleration of gravity is on the planet where you weighed yourself to get your mass.
@B.L.E. The 2015 4 wd v6 Colorado crew cab short bed weighs in at about 4300 lbs. (officially 4329) As individual options make a difference. The weight of the crew cab v6 Tacoma is about 4200 lbs. and varies also depending upon options. So, if 100 lbs makes “that” much of a difference, the 70 extra HP still isn’t doing it’s job. I would say at 100lbs diff, , the weigjts are pretty equivalent.
Dag,its like a friend of mine,who showed His skeptical brother how good his little Toyota V6(BY TODAYS STANDARDS)would pull,there is more to it then top HP numbers,you have to allow for gearing,power band etc.I’ve seen huge engined vehicles that were practically worthless,because they were geared wrong
None of it makes a doggoned bit of difference. Horsepower is the measure of power that the world has standardized on for automobiles. Everyone is welcome to convert it to their measurement of preference, but anyone arguing that the standard is wrong and using theirs instead is simply refusing to accept the measurement that the rest of the world has deemed proper.
The world wins, 7 billion to one.
Europe, at least, uses kW instead of HP and N-m instead of lb-ft. Since mst of the world is metric, I imagine most of it uses the MKS designations.
^And Germany uses PS (German “horsepower”) that is so close in measurement to our HP that you wonder why they’d bother…
Europe, at least, uses kW instead of HP and N-m instead of lb-ft. Since mst of the world is metric, I imagine most of it uses the MKS designations.
The US uses the metric system for a lot of things, just not everything.
Also, the rest of the world is not as strictly metric as many of us think. Gold and other precious metals are still traded by troy ounces and pennyweights in most of the world, even the metric countries. The nautical mile is still the preferred unit of distance for navigation, since it is by definition exactly one arc minute of angle around the earth.
The USA is supposed to be on the metric system,but there are a lot of Holdouts,guess what metric part(or at least part of it )has been on American cars for over one hundred years.
I’m guessing ball bearings. A 6205 ball bearing has a 25 mm bore, a 6206 has a 30 mm bore, etc. BTW, the metric system is way over 100 years old. If you are reenacting the Revolutionary War and you are using a French Charleville musket, the screws in the lock should have metric threads in order to be historically accurate.
Americans have widely accepted metric medicine doses.
Metric electrical units.
Metric wine and whiskey bottle sizes.
Metric rifle and pistol calibers.
Metric foot race distances.
Metric engine displacement measurements.
On the other hand, “metric” countries make motorcycles with the rear wheel driven by #530 and #520 roller chains. The “5” in 530 is the pitch, 5/8 of an inch, and the “3” in 530 is the width, 3/8 of an inch. It’s a case of not re-inventing the wheel I suppose. Metric countries still make and use “12 gauge” shotguns, in fact, there is no metric spec shotgun that has any real popularity, although 18.5 X 70mm is an alternative term for “12 gauge”.
@ dagosa I feel that 60 to 80 acceleration times are a better indicator of passing power than 0 to 60 times.
I have noticed that on super sport motorcycles, the zero to 60 times for the liter bikes are not significantly lower than the zero to 60 times of the 600 cc sport bikes. Around 2.9 seconds. I believe the 600’s have already reached that saturation point where more power is just more wheelspin during a zero to 60 acceleration.
@BLE I agree. They should be much better with 70 more hp… In practical terms, toyota owns the off road market and with 90% of the torque at 2k, it should have an edge at lower speeds starting off, even with the 12 year old motor. The guys on the Tacoma forum are bonkers thinking their newer 3.5 on the 2016 Tacoma will loose the low end grunt and just become another “car motor” like the Colorado with lower torque numbers but higher HP.
They don’t like the idea of developing all their horsepower at 6000 plus rpm and being a better vehicle on the interstate but having to work so much in the high speed range. The Fastlane Gauntlet towing runs comparing the old 2015 Taco design to the newer 2015 Colorado showed just that. They floor these vehicles towing 5k all the way to the top. The Colorado is faster, but works well above 6200 rpm all the time. The Taco a little slower but never looses speed and works around 4000 rpm…
Truck guys like truck motors for lower rpm power and will easily sacrifice the high speed passing preferred in a car for low end grunt. Turbo charging on Fords give you both, but at the expense of complexity. It remains to be seen how the newer Atkinson cycle dual injection Taco will have for numbers…it certainly won’t have 305 hp as Toyota is not “big” on high horsepower in their Tacos…never had been. The 2.7 four will have just 160 hp vs 200hp in the Colorado…but both will have identical torque. Toyota used the same approach vs the last Colorado for the last ten years; lower hp, flatter torque and better off road grunt. ( and fewer problems) Taco nuts are hoping for LeSS hp and more torque in the lower range. Bottom line, high hp alone isn’t where it’s at for trucks.
Well according to my info,sparkplug threads have been metric for almost as long as they have been manufactured,dont know why,maybe it was some foreign manufacturer that made the first practical spark plugs.
Model T spark plugs…1/2" NPT.
Model A plugs…7/8"-18 UNS.
Good catch, most every other plug I have seen,has a metric thread(knew there had to be exceptions,never owned an early Ford,I imagine Henry would have deliberately have made everything standard American,He was a stand up Guy,for the farmers in particular,I imagine a lot of Farmers owned the threading sets for the metal pipe.
I know what NPT is,what is UNS?
Unified National Special.
It has a thread pitch that is unique to that application.
Back on subject.
Why can a vehicle with more horsepower not have significantly more acceleration than another vehicle that weighs the same?
One factor might be the engine’s rotational mass, or flywheel mass. The engine has to accelerate its own flywheel along with the vehicle. The energy needed to spin up the engine’s flywheel is proportional to the square of the rpm, i.e. a flywheel spinning 6000 rpm has four times the kinetic energy of the same flywheel spinning at 3000 rpm.
It’s entirely possible that the Colorado’s engine consumes a pretty good percentage of its 70 extra horsepower accelerating its own flywheel, alternator rotor, crankshaft, etc to 6000 rpm in each gear during the 0 to 60 acceleration test.
For top speed, the engine runs at a steady rpm so all its horsepower is available to turn the wheels.
Some of the Formula 1 cars used V-8 engines with flat cranks simply because that eliminated the need for counterweights on the crank thus minimizing crank inertia or so I hear. Every horsepower needed to spin up the engine’s own crank is a horsepower not available to accelerate the vehicle, and when you have engines that spin upwards to 18,000 rpm, the energy tied up in crank inertia is not trivial.
@BLE Agree again. There are tons of different reasons. But, they all make the point. Hp ratings are not the end all be all in the performance you may want. The take of those on the Tacoma forum who all own these and other trucks is simple. The taco has MORE torque and the same hp at lower speeds so the first thirty to 40 mph will usually have the Taco ahead and the distance made up with the higher HP at higher speeds. The Rev limit of the Taco is 1400 (5400) rpm less then the Colorado. (6800) pretty much coincides with the better high end too.
Now, if we are looking at engineering “problems” to assign to this difference in performance, perhaps you’re buying the wrong truck. In that case, you are stuck with a dog withh lots of horsepower whose advantage is only realized by a higher top speed. I give GM, more credit and think it’s just a trade off they make, a little torque down low for economy in a more modern engine. Of course, the final drive ratio is "another " factor.
So, the other day I am on my way home from playing indoor golf driving up 1A doing 50 mph in a 45 zone four car lengths behind anoher truck also behind a line of ten cars. A freek’n SUV with a NJ plate passes me on the right using the break down lane and weaves in front of me one car length away and stays there for the next 5 miles till I turn off.
There was an instance I wish I had 300 hp when he was beside me while passing. Probably good I didn’t.
@dagosa–The SUV with New Jersey plates that passed you on the right was probably Chris Christie trying to stay in the race.