Bosch plugs arent all they are cracked up to be from what I have seen over the years. Over the last how many years, when it gets cold outside(like under 10-20 degrees or colder), quite a few of the no starts I see are due to the bosch plugs that were put in. Platinum plugs are harder to produce spark over a conventional style plug and when it gets cold outside it really shows. I refuse to install Bosch plugs in anything because they dont seem to last and dont live up to their claims. Maybe they work fine in a above 30 or 40+ degree enviroment just fine but here in Michigan when it can get pretty cold sometimes below zero they just dont work very well.