My 1996 Accord EX's v-tec kicks in at 3800 rpm. driving at 100 mph in overdrive puts me just above that, and my gas mileage NOSEDIVES. (it is already pretty bad at 100 anyways, of course I can't really measure it accurately, though, so i can't say by how much or anything. But yeah, the difference between 95 mph and 100mph is huge because v-tec kicks in between those speeds. (My job requires some long-distance freeway driving. can you tell?)