But why use this technology only for efficiency reasons? (chloerutzerveld.com)
This also applies to many all wheel drive cars these days: for fuel efficiency reasons, many are front wheel drive normally and the rear wheel drive is connected only when necessary. (mechanics.stackexchange.com)
For efficiency reasons, robot vehicles will inevitably tend towards being as small as possible, to the extent that they may become little bigger than the objects they are transporting. (gigaom.com)