difference

Nothing... they are generally both worth nothing .

You are at the mercy of the supplier unless you can afford the time and money to go through the courts.

Cynical old Del

In my professional experience I never used the word guarantee, only warrantee.

I lacked the Omnipotence to "guarantee" that something absolutely would or would not happen, due to the trivial, yet possible chance of some random occurrence negating whatever it was i was 'guaranteeing.' stray cosmic rays, sky lab falling on it whatever.

In a warrantee situation, I was 'warranting' that it was in fact exactly as i described and so could be expected to perform as befits its commercial desciption.

The test reports were a record that I used to warrant the analysis; A product warrant submission to an auto company as part of a level 3 PPAP would warrant the material, its description, properties, processing, attributes, origin , test methods etc. See the part submission warrant here: http://www.keysafetyinc.com/supplier_info/quality/PPAP/index.htm

I hate to be the one to lapse into theology here, but thats how I explained it to my subordinates when I instructed them never to use the word "guarantee:" "Unless you are a god with divine powers, you cannot guarantee anything. You lack the power. You lack the ability to be everywhere to "make it so." You can only do your best.You can however warrant, that the product is as we describe and will perform as expected. We warrant the product of our process, we donot guarantee anything."

So if your name is Zeus and you can make lightning strike to make sure something bad doesn't happen, thenby all means make a guarantee. For the rest of us mortals, we will warrant the true facts of our product/process.

my approach.

milo

I believe a warranty is limited in coverage, either in time or specific conditions, or both. When I sold auto parts, the company had a presentation by the battery company manager. He pointed out that most factory defects on most products will show up within 90 days, and that's why the company offered free replacement within that time, and prorated the replacement cost over the rest of the term of the warranty. Some of the lines we carried offered 1 year or lifetime warranties to give them an advantage in sales.

A guarantee is more open-ended.

That's all I can tell without consulting Wikipedia.