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Originally Posted by sheepdog 44
Also, a typical belt CVT takes about a 3-5% efficiency hit compared to a manual transmission. On top of that, the 1:1 gear ratio of a manual transmission is the most efficient than any other gear ratio at around 98% efficient (going from memory).
Remember where talking range extended EV's, not range extended Serial and Parallel hybrids (Chevy Volt / Plugin Prius). A pusher or a genset is something that you ideally would rarely use on an EV, so what costs the least is likely the best option.
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Agreed; cost of the system should be a factor... however, we haven't addressed that yet.
Quote:
Originally Posted by sheepdog 44
A genset is cheapest and far lighter cause it excludes drive components, and added rolling resistance. It also has the ability to be removable. A genset that cannot provide 100% of the power needed at all times is a better option. Like the 600cc iBMW range extender that doubles the 100mile EV range to 200miles before it needs to be plugged in. The smaller your engine, the cheaper, the lighter, the easier to make removable from the EV. Otherwise you have a heavy Volt that always needs to carry the dead weight. If you had to build a business model on a pusher trailer or a carry on/ towable generator, The generator would win hands down.
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Not necessarily true... a 21kW genset (that's sized to offset the 65mph steady state consumption of a Nissan Leaf) on a trailer already weighs 1675 lbs and costs $11k... compared to an example 1100 lb pusher for $1k. I agree we can downsize the genset, but as mentioned before, now we're falling outside the stated goal of unlimited range. And again, it's also possible to downsize the pusher, also for limited range. And then we start getting into what-ifs, etc.
Quote:
Originally Posted by sheepdog 44
Another point is that the pusher needs to be scaled large enough for peak horsepower (for trailer and vehicle), unlike a smaller genset which only needs to provide average power over a period of time. And with traffic included, that average can be lower still. Generally an engine that must provide peak power has a larger displacement, and thus is less efficient at a low power cruise.
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Not sure why the pusher needs to be scaled for peak hp... why couldn't the EV help? Now, the pusher I've been talking about is already sized for peak horsepower, but it doesn't have to be. Just like downsizing the genset, it'd be possible to downsize the pusher, and the EV can help wherever the pusher falls short. Again, that falls outside our scenario, but it's certainly possible... and we still don't know which (of the downsized components) would be more efficient from a fuel consumption per mile perspective.