Does cruise control save gas. and running the air condition use ?

Using the cruise control can help – it depends on what kind of a driver you are, vs. the cruise. The AC definitely uses gas, it’s another load the engine is trying to pull.

Instead of running at 60mph, try leaving five minutes earlier and drive 55 (with the cruise on, if you have a tendency to creep up) – you’ll be amazed what a difference just 5mph can make.

Also:

Check your tires. Inflate them to the maximum printed on the tire sidewall.

Take the roofrack off, if you have one. If you never carry anything up there, you’ll never miss it, but the difference in your mileage is as if your tank suddenly got one gallon bigger. Really.

Look far ahead. If the traffic light you can see a quarter-mile ahead is red, then get off the gas now. There’s no point in hurrying up to stop, and just maybe you can coast long enough that by the time you get there, it’s green again: double bonus. Not having to accelerate back up from a stop is a big savings.

Go to Ecomodder.com and CleanMPG.com for more hypermiling ideas and suggestions.

Using cruise control is the best way to save gas at any speed. I have an Audi and Vag-Com tool that will graph throttle open %. When I try to drive smoothly my foot was automatically opening and closing the throttle. But using the cruise control the computer was making smooth and tiny adjustments.

Just as a reference, yesterday I drove back from Boston to NYC (202 miles) all on cruise control (middle of the night). The cruise control was punched in at 72 MPH. And I calculated the gas used and the mileage. It turns out my Civic (2nd car) did 41 MPG even at 72 mph. WOW !

I don’t think i could have done near that amount using my foot.
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As for AC, it is supposed to save gas when driving on the HWY. On the street speed (low speed / stop and go) open window is better.

Good Luck.

P.S. I heard yesterday on morning show that every 5 MPH above 55, it is like paying extra $0.30 per gallon of gas.

Using the cruise control saves gas and give you better gas mileage unless you are traveling over hilly terrain. The air conditioner does cause your engine to work harder and so does use gas in a sense. On the other hand it burns more gas to ride with the windows open because it causes aerodynamic drag and makes your car less efficient. Using the A/C is more cost effective in modern cars. It’s been proved that going 5 mph less (or 50MPH) can save more gas than you would have guessed. On the highway a constant speed of 50 offers a reduction in wind resistance which your car is pushing against.
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using cruise control helps gas mileage but air conditioners make the engine work harder wich uses more fuel.