Learning any language is a worthwhile valuable skill and worth a mention on an application. Swedish isn't one of the more common 'business use' languages I come across and I doubt it is of huge advantage for engineering, other than it could facilitate working in Sweden. Mind you everyone there probably speaks English. The only other benefit I can think off would be the advantage of being able to impress and chat up Swedish folk in their native language - they're a good looking Nation in my experience, particularly the women. In short I would go for it..