I didn't know either but if you look at the maintenance schedule it says to change non-plat every 30k and all plugs at 60k. That is also echoed in the maint section on this site.
http://www.4x4wire.com/toyota/maintenance/tacoma_4runner_30k/maintenancep3.html#plugsThe only thing I can figure is that the plugs under the coil packs get a slightly better spark so perhaps they figure they could get away with non-plat on that bank?
Are you sure that you had 3 platinum and 3 non-platinum? Or did you just have the different brands (NGK/Denso)?
The maintence schedule is a generic version for all Toyotas of that year, that is why they list both Platinum and non-Platinum plug change schedules. And the link only seems to mention the non-platinum that the trucks use.
I think a lot of their cars had the platinum and their trucks had the non-platinum.
hupptoy
You're right, I'm not sure. Just noticed different part #'s. However, it was obvious that only 1 bank was changed at 60k miles. That's the only service I ever had done and I bought the vehicle new.
By the way, I also noticed that the ground wire from the battery negative terminal to the body broke. I apologize for getting on my soap box but it really drives me nuts how battery manufacturers insist on ignoring the original battery dimensions thus allowing the replacement battery to shift around in the tray. I mean sure I can put a piece of plywood in the tray but how many people are going to do this? God forbid the battery hit the fan and spray acid all over!
