Transportation emissions are a big part- in Oregon the biggest part- of our climate changing emissions. One way to make a huge difference- at a large initial cost- is to switch mobility needs from petroleum driven to electrically driven.
And fuel cost per mile is much lower. 85% of the energy in each gallon of gasoline burned goes out the tailpipe or the radiator as excess heat. 85% of the energy in a battery powered car is used to move the vehicle. Even with line and charging losses, the electric vehicle is far more efficient. Yes, there are problems with battery production- solvable problems. Our electricity is hydro produced so we kill salmon instead of generating carbon dioxide. The petroleum problem is well documented.
But while you are still driving an internal combustion vehicle, doing it better is the right thing to do, and will save you money. Question one- what's the rush?
All autos get better mileage at slower speeds. And a 5 mile trip at 55-miles-per-hour takes less than a minute longer than the same trip at 65. On a long trip, speed saves real time. A minute a day is really nothing- you can't save them up.
Drive like there's an egg between your foot and the gas, AND your foot and the brake. Rushing away from the green light and braking hard at the upcoming red light wastes fuel and wears out brakes. I drive this way, and after 200,000 miles, I am still on the original brakes in the 17-year-old vehicle.
Get your errands plotted out, and make the trip efficiently- or do without something for a day or until you will be in the neighborhood.
Of course the bus is better. Organize a carpool. Biking and walking have health benefits too. Electric and fuel cell vehicles are near zero emission, but until you can make the switch, drive like you care.