Just so you know how to read a chassis dyno sheet -
If it takes 30 hp to roll two tires with 1700lb of downforce on them at 30 mph, it takes pretty close to 50 hp to roll them at 50 mph, and 70hp at 70mph. We are talking rolling losses. It's why a static HP output on a chassis dyno will slope down linearly. The motor is not losing power, it is accumulating losses.
Speed limiters aren't cutoff switches. They curve down or you'd 'stutter' like a racing rev limiter.
Chassis dyno pulls don't start at zero mph. Not enough traction and not safe. Even a Spark has enough initial thrust to hurt people.
So what do we see? A lot of smoothing and some interpolation was used to make the graph.
That pull started at either 3 mph (unlikely), 30 mph, or 42 mph.
Why the HP curve flattened at 75 mph is a mystery, since that means the HP actually climbed. A horizontal line on a chassis dyno means motor output is increasing at the same rate as the rolling drag.
The ramp down from 85-90 is what it looks like when you approach the speed limiter.
Another puzzle is why if there are 35HP losses at 42mph that there is 50HP losses at 80mph, but we really don't know what HP a Spark EV puts out. It's badged at 140HP. The curve COULD be correct. It's just very unlikely. Especially that flat at 75mph, not buying that. Most likely GIGO kicked in.
From the earlier Volt graph, you are showing over 50% rolling losses. That's wrong. A G1 Volt puts out about 162-165 whp to the rollers, or just over 120kW. All Volts are advertised at 111kW SAE at the motor. I haven't seen a G2 on the rollers yet but they more powerful than the G1's even though both are badged 111kW. There is no massive boost in power when running the ICE engine. I race both ways and don't see a difference. Some report there is a difference, but I doubt it. It's unlikely we got 3 'unique' cars. Peak output is controlled with software, think of it like a cruise control. Only the ELR increases output significantly when running both ICE and battery. That feature is not on the Volts even though the motors are the same.
The comedy hour is the Prius graph. That proves the Prius is quicker than Volt. The PiP is about 600lb lighter, so it should walk away. Trust me, if there is a driver in the Volt, that's not happening. It's not just the power to weight, the Prius is a freakin' SLUG from a stoplight. You want to open the door and push with your foot.
