For diesel I wanna throw in my vote for TDS/EFS card. While the truck stops "list" price is always high, from what I have seen I save .10 to .30 / gallon compared to stations on Gasbuddy in the vicinity. That plus the easy in/out of the truck lanes and being able to fill both the truck and the transfer tank (opposite sides) from a single transaction make it MORE than worth it to me.
Heck, when on the road I used to use the truckstops for those conveniences even without the discount!
-Chak
Oh, there is a referral program as well - the referrer can get $25 credit after the new user pumps 100 gallons.....I'm not looking for that from you all, didn't provide the info, just letting ya know.