Trenchers are the best all around tire that I've run, the Dirt Hawgs are second. The dirt Hawgs seemed to wear a little fast for me, at the time most of my runs were on concrete, the 2.2 Dirt Hawgs seemed pretty soft and I haven't run the 2.8 version. I've never run beadlocks but I've read about them adding a good bit of weight, you add that to the added weight of 2.8" off road tires and your .15 may be struggling to turn them. The added weight could be countered by changing the gearing but that can only do so much before the top end is affected and it may cause you to not enjoy your car as much. If you're sticking to at least most of you're driving on dirt, just grab a set of 2.2 Dirt Hawgs. After you're engine either dies or you decide to go bigger look into the 2.8 Trenchers or Dirt Hawgs.