Deferred interest doesn't mean that they will wait and if you happen to miss your last payment they will put interest on the last part that you owe for the last couple of weeks until you pay it. What it means is that if you miss that last payment, that payment is hit with the interest in a retroactive way. You will be taxed on that last payment as if it has been late for the last six months. With that being said, you really don't want to miss payments. The unfortunate thing is that life happens to all of us. Sometimes there will be circumstances that would otherwise cause you to have to miss a payment on something in order to pay something else. Even in this case, just prepare yourself that if you miss that payment for any reason during that six month period you will be regretting it for probably the next six months or more.
If you will be able to successfully use your Firestone Credit Card and make your payments no matter what, then you should have no problems at all. So really, when you use the Firestone Credit Card to buy some new tires, it seems that that will really be the only set of tires you may want to put on the card. Unless perhaps you just feel like taking the chance and replacing tires on a few vehicles all at one. If that's the case, then by all means, go for it. We just want to leave you with the serious warning that should you miss paying your Firestone Credit Card even once, you may surely regret it.