copied from main post:-
"I-dsi:- I-dsi stands for Intelligence-dual and sequential ignation.In this type of engine,two spark plugs are employed for each cylinder.That makes 8 spark plugs instead of 4 plugs used by most cars.Adding of an additional plug assures complete burning and utilizing the last drop of fuel thrown into the cylinders which would provide you the best performace and better fuel consumption.Not all the times the 8 plugs are working,but when u push your car through high revs or speeds,all of them work simeltaneously and thats when ypu can feel the difference.But theres one drawback in it,this engine is equiped with 8 valves not 16.Hence it decreased the performance and city seems to be out of breath after 5000RPMs,but as this is basically a family car,performance is not the priority.The best thing about this was the fuel economy,about which,you can read the paragraph below. "
as for vario, it just refers to variable transmission type. basically there are infinite number of gears in vario ( CVT = contineously variable transmission"
instead of fixed gears of fixed sizes, the CVT (vario is the version of city idsi which uses CVT tranny) has a cone sort of thing inside it which changes its path contineously. this way, one NEVER feels any gears shifts and if u floor the car hard, the RPM would simply stick to the max range and the car will accelerate to its top speed without any shits... here are a few videos to explain...
see how the RPM does not falls at any point, i.e. no gear shifts
2009 Maxima 0-130mph - CVT - intake, grounding kit only - YouTube
different designs of CVT
Dodge CVT Animation - YouTube
Belt CVT animation - YouTube
CVT explained - YouTube