Only These Two States Still Have Gas Under $4 a GallonGas under $4 a gallon… weren't those the days? Well these days it's rare, to the point that only two states can offer it. Indiana is currently the cheapest place in the country to fill up, with regular averaging $3.88 a gallon, and Texas comes in just behind it at $3.92. Everywhere else in the country, drivers are paying more than four bucks a gallon, and in a lot of places, considerably more.As a whole, the national average has crept up to roughly $4.48 a gallon, which puts Indiana and Texas about 60 cents below where the rest of the country is sitting. For context on just how unusual sub-$4 gas has become, this past Labor Day was the first time in history the national average sat above $4 during that holiday weekend. Cheap gas isn't the norm anymore. It's the exception, and right now that exception sits in just two states.Why Indiana and Texas Are Winning at the PumpThe short answer is geography, and the longer answer is refineries. Okay, they're both pretty short answers, but let's get into this.Both states sit close to Gulf Coast and Midwest refining capacity, which cuts down on the transportation costs baked into every gallon sold elsewhere. States far from that infrastructure, or states that require special low-emission fuel blends, simply pay more before a single drop reaches the pump. Add in each state's own gas tax rate, and you get a pricing structure that varies plenty.Texas has leaned on this advantage for years, but Indiana's showing has been the real standout lately. Over the past twelve months, Indiana posted the smallest statewide price increase in the country at just 8.3%, while plenty of other states watched their averages climb far faster. That's not Indiana getting cheaper so much as it's Indiana getting hit less hard, which in this economy counts as a win.Compare either state to California, where regular gas is running about $6.35 a gallon, and the picture gets almost comic. That's a spread of roughly $2.45 a gallon between the cheapest state in the union and the most expensive one, driven largely by California's stricter fuel formulation rules and its limited pipeline access compared to the rest of the country. Hawaii and Washington aren't far behind California either, both sitting above $5.50.What This Means for Drivers Everywhere ElsePrices have shown the first sign of relief in two weeks, ticking down slightly after climbing on the back of renewed conflict in the Middle East pushing oil markets around. That dip is small comfort if you're not filling up in Indianapolis or Houston, but it does suggest the run-up hasn't fully locked in yet.For everyone outside those two states, refining location and state tax policy are doing more to determine your gas bill right now than anything else. If you want gas under $4 a gallon in America right now, you basically need a Texas or Indiana address.