Indeed. Whenever I take my car in for a tune-up, I make sure to tell them what pressure I want the tires at. I do see a meaningful mileage increase from just a couple PSI difference.
One thing I didn't see any politician bring up that would make a bigger difference than tire pressure or regular tune-ups: driving habits. I've always been a cautious, conservative driver compared to many people on the road. This summer, while not going overboard, I've taken that to a different level and noticed a 10-15% improvement in my mileage. I now get 20-40% better gas mileage than people who drive the same vehicle in similar weather and traffic conditions. I actually get better mileage than my vehicle's EPA estimated highway mileage while driving in primarily city traffic. Just imagine how much oil and pollution we could save if people didn't constantly perform jackrabbit starts and stops and stayed within 5 mph of the posted speed limit, much less not exceed the speed limit at all.
Sure, I get tailgated at times but I'm generally safer and I'm saving a lot of money by making fewer trips to the gas station.