Looking to buy my first duramax

According to GM you don't have to use additives. Personally, I use stanadyne on every tank. I think it costs around $20 for 1/2 gallon and it treats up to 240 gallons. The only time that it is recommended to use the additive, is when the temp drops below zero....even then, the local places should already blend the fuel so it doesn't gell. Also, in the winter time your mileage goes down because of this. From what I have read, the new engines will be running on ultra low sulfur diesel. I guess that means the rest of us will be running additives more often. You end up having to change your fuel filter more often on a diesel because the fuel is so dirty. I believe the recommendation from GM is every 15,000 miles. I feel this is too long....I have changed my filter at 8500 miles and it was almost all the way black. Their filters run about $45 from a parts store all the way down to about $20 a piece. Also, if you get the Allison, plan on changing the external filter often too to protect it from damage. The change intervals are 10,000 miles. Although, Mike L. will tell you it is too long...he feels every 5000 miles is more needed. He is very knowledgeable with the Allison, so I am trying to keep to that and no more than every oil change between filter changes on my allison.