what engine is more reliable with less repairs. the 4 cyl or the 6 cyl?

Typically a 4 cylinder is less costly to maintain, in that there are less parts, the T-belt job costs less etc. As to which is more reliable, that is very, very dependent on the owner, in that if you use fully synthetic oil and change it every 4k, flush your cooling system every 2 years with factory coolant, fix ALL oil leaks in a timely manner, make sure that your plugs and wires are factory quality and no more than 30k old ( the 60-80K time frame is too long ) etc.