Do you expect marketing to understand torque? Engineers & physicists aren't exactly their largest target audience.

Just guessing, but there's probably 2 motors/trans-axles for F & R. That's the direction every FWD/AWD unibody is going & I can't see running full transmission/diff & driveshaft the full length vs running a wire to the back. cutting weight is king.

quote:

Originally posted by BigSwede:
Haters gonna hate

Physics gonna physics.

quote:

Originally posted by snidera:
Do you expect marketing to understand torque? Engineers & physicists aren't exactly their largest target audience.

Just guessing, but there's probably 2 motors/trans-axles for F & R. That's the direction every FWD/AWD unibody is going & I can't see running full transmission/diff & driveshaft the full length vs running a wire to the back. cutting weight is king.

I'd expect that as well. It's a good balance between cost, complexity, serviceability, and weight management.

I don't expect marketing to understand physics but reporting torque and horsepower numbers has been established by the industry since the 70s. That was the whole net vs. gross horsepower debate back in the muscle car era.

For those of you not familiar, muscle car horsepower used to be reported as a bare engine without exhausts, air cleaners, etc. using a measure called "gross horsepower." In the early 70s (and to this day) the industry shifted to providing net horsepower which was measuring the output of the motor as if it were in the car. It was not uncommon for those motors to lose 50 to 70 hp going from gross to net hp.

Put it another way, every car maker for the last ~50 years has reported torque and horsepower identically. For GM to all of the sudden come out with their own measure that includes gearing in order to produce a "big number" is about as close as you can get to flat out lying.

It’s not just GM doing this. The articles I have read said electric is measured at the wheel. BMW just had a vehicle that was rated at 11,000ft lbs and was quoted as being around 800ft lbs if measured in traditional ways.

That means the Hummer will still have over 1000ft lbs if measured in the traditional way.


Typically torque output is the rotating force delivered by the engine's crankshaft to the transmission and, subsequently, to the drive wheels.

The problem with measuring electric is that torques rotating force is not delivered to the crankshaft and then the driveshaft it goes straight to the wheels.

The industry could normalize things if they wanted to. Just put the cars on the dyno and how the power is transmitted to the rollers is of no consequence. It will show the power that is getting to the ground which is all that really matters anyhow.

quote:

Originally posted by 1s1k:
It’s not just GM doing this. The articles I have read said electric is measured at the wheel. BMW just had a vehicle that was rated at 11,000ft lbs and was quoted as being around 800ft lbs if measured in traditional ways.

That means the Hummer will still have over 1000ft lbs if measured in the traditional way.

In that case, I have a 25,000 ft. lbs. bicycle that I'll sell ya...

quote:

Originally posted by caneau:

In that case, I have a 25,000 ft. lbs. bicycle that I'll sell ya...

Not sure what that has to do with why electric is typically measured in a different way.

If they don't stick to the accepted standard of measuring power the numbers become meaninglessness. Every manufacturer could come up with their own way to get impressive numbers to advertise. No one wants to look for small print for a disclaimer that says " horsepower and torque ratings are for entertainment purposes only".

quote:

Originally posted by 1s1k:

quote:

Originally posted by caneau:

In that case, I have a 25,000 ft. lbs. bicycle that I'll sell ya...

Not sure what that has to do with why electric is typically measured in a different way.

Because with sufficient gearing even a bicycle can put out ridiculous amounts of torque. Of course your front chainring would be tiny, your rear chainring would be absurdly huge, and the bicycle would never travel fast enough to stabilize. But it would be possible on paper!

How long will the battery charge last?

flashguy

A whole three seconds huh?!

That's pretty good....

....for how long it takes a GM product to wind up in the shop.

quote:

Originally posted by caneau:

quote:

Originally posted by 1s1k:

quote:

Originally posted by caneau:

In that case, I have a 25,000 ft. lbs. bicycle that I'll sell ya...

Not sure what that has to do with why electric is typically measured in a different way.

Because with sufficient gearing even a bicycle can put out ridiculous amounts of torque. Of course your front chainring would be tiny, your rear chainring would be absurdly huge, and the bicycle would never travel fast enough to stabilize. But it would be possible on paper!

The point is there is no gearing so they are measured differently than IC engines but the same amongst themselves.

I say put everything on a dyno so we know what power is hitting the pavement. That’s the only thing that matters anyhow.

quote:

Originally posted by 1s1k:

quote:

Originally posted by caneau:

quote:

Originally posted by 1s1k:

quote:

Originally posted by caneau:

In that case, I have a 25,000 ft. lbs. bicycle that I'll sell ya...

Not sure what that has to do with why electric is typically measured in a different way.

Because with sufficient gearing even a bicycle can put out ridiculous amounts of torque. Of course your front chainring would be tiny, your rear chainring would be absurdly huge, and the bicycle would never travel fast enough to stabilize. But it would be possible on paper!

The point is there is no gearing so they are measured differently than IC engines but the same amongst themselves.

I say put everything on a dyno so we know what power is hitting the pavement. That’s the only thing that matters anyhow.

Yes, there is gearing in electric cars. It's just a single gear ratio. Tesla's is like 10:1. There has to be gearing -- motors spin at thousands of RPMs. Tires spin at hundreds of RPMs. And a 10:1 ratio is a pretty good, mid-range sweet spot for gearing in a car. It's like 2nd gear in a 6 speed transmission (taking into account the differential gearing as well).

The difference with electrical motors is that 100% of your torque is available at 0 RPM while any gas or diesel engine has an RPM range "sweet spot" where it is producing maximum output. With diesels it's somewhere between 800 to 1500 RPM, with gas motors it's often closer to 4000 or 5000 RPM. Your transmission allows you to take a finite amount of total power output (horsepower or kilowatts) and convert it to some combination of force (newton-meters or ft. lbs.) and RPM. Lower gears have more wheel-torque and lower RPMs, higher gears have greater RPM and lower wheel torque.

Dynos have to account for this to give accurate, gearing-adjusted torque readings. That's why you run a dyno in a single gear and enter in your gearing information (although I believe modern ones auto-calibrate using ECU data).