Gasoline prices have reached their second-highest peak in Iowa history and many of us are having to re-learn gas conservation lessons from the 1970s. Despite gas averaging a dollar-75 a gallon in Iowa, the number of motorists on the road for Memorial Day weekend is expected to go up. Triple-A Motor Club of Iowa spokesman Daron Van Helden says before taking off, make sure your vehicle is in good operating condition.He says you should check your tire pressure, air filters and spark plugs to insure the car’s getting the best mileage possible. There’s also driving style: don’t accelerate rapidly or make sudden stops, keep a constant speed and don’t use the air conditioning if you can stand the heat. Van Helden says shopping around for the best pump prices is also wise.Van Helden recommends simply watching gas station signs for who has the lowest price, though he says it’s nuts to drive miles out of your way just to save a penny a gallon. An Iowa D-N-R survey finds the statewide average is now a dollar-75 a gallon, up 16 cents from last month. That’s 31-cents higher than a year ago. This is the second-highest monthly average in Iowa history. The record was set in June of 2000 with a dollar-77 a gallon.