Balance is not affected what so ever!!! On the cylinders you kill, you need to keep the valves closed. Yes, the engine will use power to over come compression on the dead cylinders, but that built up compression now push the piston back down. Making the pumping loses almost a wash. Now you have to deal with ECM. You're on your own for that one!

Balance may or may not depending on the cylinders. but smoothness most certainly will. An engine with X cylinders minus any IS off balance from factory. The crank counterweights, balance shaft (if present) etc all are based on all cylinders present and working. if you any cylinders you WILL feel it. Especially on an I4

I would like to see anybodies balancing formula that says anything about the number of plugs or compression or anything other than weights. Yes the engine might shake from uneven cumbustion, but that's not the same as balance.

You obviously know what everyone's talking about so quit being an anal retentive troll and move on.

Summary of entire thread: Removing bits to disable cylinders will make the engine shake. how much it shakes depends on the engine type and which/how many cylinders you mess with.

while taking mechanics of materials(also known as strength of materials) in college we learned about the angle of twist. i do believe you will throw that angle off if you disable one or more of the plugs, you're losing a force on crankshaft that it was designed to have.

i don't understand how you can keep the valves closed, i thought the lobes on the camshaft opened & closed them? edit:-->though i could be and probably am wrong about the valves.

I think if you remove the whole engine it wouldn't consume any fuel. :p

But seriously, it won't save fuel because you still have to power that cylinder, it will just turn it into a badly running engine and severely hurt your mpg.

Just give up on this stupid idea... if the engine wasn't built that way don't mess with it!

GM has been doing this since the early 80s.

Yes, and it worked so well that people were lining up at mechanics to have the system disabled! and their engine WAS designed around doing it. there are quite a few things GM does that I wouldn't.