^@cutlassvillager: Yes, in fact...why not a 6 month interval max? If you went over by probably twice the time frame the previous interval should have gone, it's best IMO to run a couple short intervals. SynPower isn't great at TBN retention in the first place, I know the miles are 'meh', but over 2 years? I wouldn't run SynPower for more than a year, ever. Based on their typical performance.