My 2001 Maxima has 100k mile spark plugs and 8k OCI for any oil (and lab tests ok to 10k+), as did my 2004 Toyota Matrix. Actually, even a 1990 Ford Taurus 3.0L had platinum plugs good for 100k (with a distributor, doh!). So there is a lot of assumption in the copper spark plugs comment, just...