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Comment by derekp7 | Hacker News Reader

If another company came up with a dual-powered version of the Tesla, then I would definitely buy that. The current round of plugin hybrids don't offer enough battery-only range for me. I'd like to see about 100 mile battery only (in case I forget to plug it in), plus a small engine and 10-gallon tank. I wouldn't think the gas engine would have to be that large, especially if it were designed to use the battery as a buffer (i.e., it would only need to have enough HP to maintain highway speed, and acceleration could be handled by the battery).

Which brings up a question -- how much horse power is needed just to keep a car cruising, without accounting for acceleration? Edit: just looked up on Wikipedia, the Model S gets 100 miles per 35kWh. So that works out to (assuming 65 mph) about 23 kilowatts average continuous output, or 30 HP. Considering that many car engines are 300 HP, I don't see a 30 HP engine being that extreme.

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The problem is that it's not just the engine. If you want an engine then you need a fuel tank, emissions controls, either a transmission or a separate electric generator attached to the engine, etc. All of that stuff adds weight and cost, or reduces the space, weight and cost budget you have for batteries and electric motors. By the time you've paid for it you might as well forget about the 30HP engine and put in a 100HP engine, at which point you have a Prius.

>I'd like to see about 100 mile battery only

electric/batteries works great for start/stops. For highway cruising, which 100 miles range would probably include a lot, internal combustion engine isn't that bad. I'd expect that there isn't much practical difference efficiency-wise between 20-30 miles battery range hybrid and a 100-miles range one, especially considering that the latter would be carrying additional at least 200kg of batteries.

I think we will start to see cars' internal combustion engines which are specifically targeted to work only as generators, i.e. highest efficiency only for specific rpm value - current ICEs available are "wide rpm and load range" designed to be a primary engine of a car. Volt (and Karma) as far as i understand have such generic engine, not a "generator" one. Dropping a lot of old requirements and having the ability to match generator to the engine, we may see very different engine types coming in which would match new requirements much better.

Depends a lot on speed, the shape of the car, and other factors, but on the order of 10-30 HP for something like the Model S at 70mph I think.

I still really want a hybrid truck, running diesel, with the ability to seat 2 people, secure cargo space (like a custom bed with lockboxes), 4wd, and the ability to run the engine for a week or two in place as a generator (e.g. at a remote comms site). Run the engine during the day to keep the batteries charged, operate at night off battery.

VIA Motors is the closest thing to this that I know of: http://www.viamotors.com/

Sadly gasoline/petrol vs. diesel. I really want diesel so I can store/transport reasonable amounts of fuel; I avoid messing with gas.

I wonder how it would deal with towing. That I6 would be inadequate for peak towing, so it would depend how often a truck going up grades, offroad, etc. and towing would need battery augmentation.

If what you want is a fast luxury hybrid, there are already high-end Lexuses (Lexii?), but I suspect you'd not like the range as much. Porche are also pushing hybrids, but again for performance, they're using the petrol.

The WEC is pushing supercapacitors into the hybrid drivetrains as a superior method of scavenging (but not storing) energy.

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