Range Extender can be turned off / disabled via menu setting screen

[colinnwn]

So my curiosity got the better of me and I decided to try to estimate the generator sizing requirements based on the different scenarios. I looked up what the Rivian pickup uses for power per 100 mi and it is 47kw. I rounded that to 50. This is what was seen by Edmunds over an evaluation period. It was mixed city/highway, not towing, and probably mostly flat ground. Changes to that mix can change the actual usage a good bit. These calculations aren't perfect but are an order of magnitude correct.

The battery to get 150 miles is likely 75 kw.
To go 500 mi you need a total of 250 kw.
The generator has to produce 175 kw minimum before you get to 500 miles
If you assume up to 75 mph on the highway, that takes 6.6 hours to travel 500 miles.
The generator output must be at least 26 kw per hour to be basically "dead" at 500 miles.
If you want to be able to fuel up and continue with average energy consumption you need a 38 kw generator.

If you have a bad headwind or it is winter and it has resistive heat (no heat pump or engine heat harvesting) it can take a bit more power than that. If you are driving in mountains and unable to regen most of the energy going down that you expended going up you need a bit more. This is particularly relevant because smaller batteries can't accept the charge back at the rate needed. I couldn't quickly figure out how to do that calculation, but elsewhere I've seen someone calculate the battery needs to have about 200 mile range to effectively accept most energy back when towing and regen braking. And if you are towing anything of decent weight and frontal area, you can about double these energy requirements.

I don't think the generator is going to be anything like a generator you'd buy at the store. It's probably going to be one of the smaller displacement VW TSI vehicle engines coupled to a generator unit, and I would have it set to operate at two speeds, a 'most efficient' and full power for when the computer can tell the battery is depleting too fast.

Storm generators can actually be pretty quiet if you put a small car muffler on them. What they come with is junk. And of course they are not carefully balanced like a good car engine.

 

[Rouse]

A four cylinder (2.0L to 2.5L) gas engine set up as a generator should be able to produce somewhere in the 25 to 35 kWh range based on what I’m seeing. If someone is more familiar with higher output gasoline generators feel free to correct me.

 

[Rouse]

The way I see the range extender is a series hybrid similar to the GM Volt but without mechanical connection between the engine and the drive wheels through a (planetary) gearset. The Volt could drive entirely on the gas engine/generator and recharge the battery along with powering the electric drivetrain without performance loss.

The Volt could also be switched to EV mode without the engine starting or switched to gas mode. This is helpful if in the future, American cities being charging a carbon emissions tax for gas vehicles operating within city limits. Numerous European cities do this already, London is one such city.

I am hoping Scout makes the Harverster option a true series hybrid. IMO it is the ideal configuration for the American driving use case.

The performance demands (energy usage) of either of the Scout models is significantly higher than an economy car like the Volt. As an example it would probably take a half dozen or more Volts to tow 8,000 to 10,000 pounds. Or as another example, the Scout models will be a little less than twice the weight of the Volt while having quicker acceleration. Adding a gas engine that produces enough energy to equal the energy usage of either Scout would require at least a robust turbocharged six cylinder and there just isn’t going to be enough room to fit that type of an engine (without giving up the frunk, cabin/bed space, departure angle; which they’ve said they’re not doing).