I'm waiting to hear back from them. At first, she tried to say that because I can buy more fuel at a time than a van, it didn't apply. After some conversation she decided I was right and that I should get one every 50. She wasn't sure how to resolve it and sent an e-mail "upstairs". She's going to call when she knows more. I'm anxiously waiting by the phone and I'll keep you updated.
I just got a call from Carol at TA headquarters. For those of us in a straight truck, it's not a shower every 50. I bought 70 today and 92 yesterday and that's 2 showers. I told her that the program didn't read that way, but that's how it is. Looks like it's back to buying 50 at a time more often.