what are good ways to save on gas mileage. My car only gets 9 miles per gallon. It is a big old junky car?

Yes,the more weight you have in your car the more gas it will use.good luck.

empty trunk and car of any excess weight remove roof racks if fitted dont speed up and slow down all the time

Make sure your tire pressure is at 35psi. Make sure you have a clean air filter. Take that $hit out of the trunk. put a bottle of “slick 50″ into your oil pan. DO NOT speed around.

Yes, increased weight load will hurt gas mileage. Whether it will significantly reduce it is another story, but the engine has to do more work (lb/ft) to move extra weight. It depends on whether youre talking about a couple hundred pounds of extra stuff or just a 25 pounds. A free fix that might help increase mileage would be to keep the tires properly inflated and check them daily or every other day.

Empty your car of EVERYTHING you don’t use – Seats, door trims, any non structural metal, exterior trims, badging etc.
Remove 33% of your spark plus and leads and block exhaust and fuel inlet ports to those cylinders.
Next advance your timing 14 degrees and open your points gap so that you can run your car on kerosene. you will need to add a valve lubricant also – washing detergent works fine.

Just kidding. Everyone else seems to have good advice.

Get rid of all the weight your carrying, Tune up the Engine- proper inflation on the tires- those old cars only get about 13 mpg, highway with luck 16 or 18 – if it has a Carburetor adjust that also it probably needs it. No fast starts-no flooring the gas pedal-

It sound like you have what I call “A Boat” usually 8 cylinders. If it a “Sled” it not worth much and you can modify your engine. IF, you know what Cylinders to “Drop” you can make it run on 4-6 cylinders instead of 8. Remove the Valve cover and Disconnect the Appropriate Valves so they not open and remove the spark plug wires. You can remove the Plugs, but, that can get noisy. What you doing is similar to the old Cadillac 4-6-8 Engine, which was a flop, but, good collector car. It would start with 8 cylinders running and as it got up speed it would shut down cylinders until it only ran on 4. This just a thought and offered as educational purposes and I not take responsibility for whatever. LOL. Hope this helps and Happy Sputtering.

Do not try dropping cylinders this is not a good idea. I have a friend who I would stack up against any mechanic around. He did this to a 65 Plymouth Fury with a 273 cu.in. engine. It got about 18 mpg before he started. The mileage dropped and the power dropped off significantly.
About the best advice I can give is Tune it up. New plugs,wires, rotor and distributor cap. Points and condenser if its that old. Time it to specs. Keep your tires inflated to factory specs. 32 to 35 lbs. Change the oil regularly. I change every 2000 miles. Empty the trunk of everything except the spare, jack and lug wrench.
Keep the transmission oil up to level. Might not even hurt to change the fluid and filter in that if its never been done. Make sure you use the proper fluid. Also check the level in the differential if it is rear wheel drive. Also grease the u-joints and steering components. Make sure your anti-freeze is 50/50.It also keeps an engine from boiling over. No jack rabbit starts and you use alot less gas at 65 mph. You use ALOT less gas at 55. If that old boat is from the era of the 55 mph speed limit that’s where they were designed to get their best mileage. I hope this helps you out. good luck!