Goodness gracious...all you wanted to know was how to maximize your fuel economy! I manage to get 31 miles per gallon city/hwy in my Hyundai Tucson (4-cylinder SUV) my son can't do better than 26mpg in the same vehicle.
What's my secret? 1st) No jumping the gun. I never jackrabbit-start from a stopped position. I accelerate slowly & evenly til I get to my desired speed.
2nd) Even-Steven: I set the cruise control (which works at speeds over 25mph) & continue on my way. Cruise not only saves fuel it helps you avoid speeding tickets cuz you weren't paying attention.
3rd) Ease on down the road: If I see the light ahead is red...or turning red or I notice the pedestrian walk lights are blinking & I won't have time to make it through the light I take my foot off the gas & coast to the light accelerating as little as possible. I don't care if somebody wants to run around me and cut in front… they're gonna to have to stop for that light & I'll be right behind them [waving]. In our neck of the woods run the light & there's a cop sitting at every intersection 24/7
4th) Chillin' out. A/C is used on hot days & the highway & only leave it on long enough to cool down the car (who says it has to be on the whole trip?). Windows need to be up as soon as you're going over 50mpg or the drag cuts into your efficiency. Make sure you have at least some fresh air coming into the car [use your fresh air vent settings] or you can get sleepy from CO2 buildup.
5th) Speed matters. I try to travel 60 mph on freeways/highways since I found I get the best mileage at that speed. You can figure out which highway speed is best for you by filling up your gas tank, taking it out for a nice drive on the freeway at one speed for ~ a quarter of a tank then refilling. Repeat the experiment 5 miles higher/lower speed. Repeat this one more time going the opposite i.e. start at 65, then do 60 & the third time try 55. Don't bother going higher than 65 since fuel efficiency drops like a rock over that. I found one really great advantage besides fuel efficiency to driving 60mph...other cars are going faster leaving me a nice, clear path so I rarely have to do any braking. Since braking frequently really affects gas mileage this helps me save $$$. I laugh at the other drivers thinking of them b*tching while handing their hard-earned money to the oil companies 'cause they wanted to get where they're going 2 - 4 minutes faster 'n me.
6th) I keep my car in peak driving condition. I change the oil & filter between 3 & 5000 miles depending on the type of driving I'm doing -stop 'n go vs highway. I used platinum spark plug wires for maximum performance & check the resistance on them every 10,000 miles after they reach 25,000 miles usage. Spark plugs are the best I can buy & I check them every time I change the oil. If they're dirty, I clean 'em & check their gap to make sure it's correct as well as the functioning. My air cleaner's changed religiously. Belts are inspected for tautness & adjusted/changed as needed. (It's stupid to let them wear down to where they break while you're on the road) I keep the last old belt in the trunk in case one snaps while I'm out & about. [yeah, I keep basic tools w/me all the time.]
7th) Lighten up! If you don't need it, don't travel with it. Carrying heavy items wastes gas. Every 100# extra weight loses you 10% efficiency. Oh, and clean up your act. (LOL) A clean car's more fuel efficient than a dirty one. (Thank you Mythbusters for proving this one, too). The dirtier the car, the worse the mileage. I bought a high-pressure attachment for my hose ($8) & it washes the car beautifully without detergents to dull the finish. Frequent washing in the winter makes your car last much, much longer. Oh, the body may look good but salt eats your fuel lines, brake lines, gas tank etc. All pretty expensive to replace what with the cost of copper.
8th) Tire pressure is checked every time I fill up the car. While the fuel's going in my tire pressure gauge's coming out. I put new caps on that let me measure air pressure w/o unscrewing the little buggers. I bought a portable inflator ($23.95) which connects to my cigarette lighter so I can correct low pressures on the spot & not have to pay 75 cents for 2 min. air. (Too freakin' annoying running in & asking the kid to switch the air on so I can do the other 3 tires - not to mention I dislike paying for air.) It's also really handy if it's dark, or a not-so-great neighborhood & I come out to a flat tire or have a slow leak...a couple of times it's gotten me home where I can change the tire indoors & then take the bad tire to the station & pay a couple bucks to have it fixed. Believe it or not, it's cheaper if the tire's off the car - you're not taking up a bay & they know you're not in a big hurry [I am, but they don't know that] so I pay less.
Tire pressure that's off by just 3 pounds will cost you 5% fuel economy! When you get up [or is it down?] to five or 6 pounds low pressure fuel economy drops by as much as 10% not to mention driving a car w/under-pressured tires causes the sidewalls to break & invalidates your tire warranty. [and yes, they CAN tell] I found that one the hard way when I had a tire with a slow leak & I put off getting it fixed because I was super busy. Cost me a set of tires (you can't have mismatched tires on axle). Now you know why tire companies change tread patterns etc every year - so you can't buy just one tire to replace what's on your car! I buy two extra tires when I buy my car or when I replace a full set so I don't have to buy more later. I get a great price (made it part of the deal to buy my last car) - & usually at least 2 tires are free of the 6.
Something you should NEVER do to help your fuel economy along is riding the slipstream of a semi or other large truck or bus. Oh, you will save fuel but if that truck or bus slams on its brakes you're history. Rule-of-thumb is, if you can't see the mirrors on both sides of the truck you're waaaay to close. (Many experts say it should take 3 full seconds from where the vehicle ahead's back bumper was to how long it takes you to get to that spot & double that on wet/icy roads.) I've spent 30 years as a nurse; a lot of it in the ED & I've seen what the back end of a semi can do to the front end of a car & its driver. If the driver and/or passenger isn't seat belted they're catapulted into the windshield. Windshields don't break easy (like in movies) & when heads hit the windscreen the impact crushes skulls & the glass shards that are melded to the plastic coating slash the person as they're forced through a tight hole. THEN you have that big rear end to deal with.
I could scream when I hear people say "Oh, I know someone who was in an accident & cop said if they'd been wearing a seat belt they would have died." BULL. I always ask the person to tell me the name of that police officer if they can't get me that give me the name of that friend. Somehow they can never remember who it was. I've known a lot of cops [my sister was Chief for 26 years & is now 'relaxing' as Chief of Detectives] and I've yet to meet a cop that'd ever advocate not wearing seat belt. Then there's the idiots who say "my car has an airbag so I don't need a seatbelt." OMG...WRONG! An airbag that deploys without a seatbelt is a quick way to a broken neck. Hell, they're dangerous enough with the seatbelt...you bet they save your life but most people end up with at least a broken nose. Trust me: I'll take that over dead any day.
So, there you go. Easy ways to save lots of $$$ on gas & staying alive while you do.