Think it was Scooby Pete that measured the boost in the different modes, i-mode gives you 0.5 bar, Sport gives you 1.0 bar S# gives you 1.5 bar - its in a post on a similar discussion somewhere on here so you will def feel a difference. Also Salsa initially found running in sport mode gave 2-4mpg difference - I found the same on mine, sport mode should really be the default mode