Strange decrease in mpg with VX when driving 65 mph instead of 72

[McPatrick]

I had this hapen once where I seemed to be getting a higher mpg going faster. This only happened once though (would have been too good) and I think it probably had to do with wind directions and such; who knows. Fact is though that if you drive more often with lower speeds you will definitely find out that the slower you go the better your mpg will be. I only wish it would be the other way around