Some engines are made that run on 6 or 8 cylinders when needed,
but generally chug along on 4 after getting up to speed. Is this mainly
a computer thingy or do the engines have to engineered from scratch for
this? If the first, are there kits available to make the conversion?
This seems the more logical, easier, and probably cheaper approach if
available.

--
"Even I realized that money was to politicians what the ecalyptus tree is to koala bears: food, water, shelter and something to crap on."
---PJ O'Rourke