I guess you gotta pay to play. Every Audi I've owned has called for 91 octane, so I'm used to those prices. But it will hurt more in a truck that gets about half the fuel economy with a tank that's twice the size LOL.So far everything that I have been able to get my hands on shows the I6, and specifically the HO version to be a fairly good powertrain, the only downside to the HO is when identically equipped with a like vehicle, except with the SO, the SO has a higher towing and load carrying capacity. Also, Mother MOPAR is saying that in order to get the full outputs of 540/521 on the HO you should be running 91 Octane.