My vehicle is using a lot of oil, what could be the problem?

leaking

or

worn out engine parts like piston rings/cylinder bores or valve guides

not much else it can be

if you're using the wrong sae grade of oil, or using semi or synthetic oil where conventional should be used, you will have a problem, typical example ford fiesta hcs engine (push rod) will eat semi or synthetic oil, but behaves itself on 20 40 or 20 50, as it's not designed to run on the former, if it blows smoke after an overrun down a long hill, when you accelerate at the bottom it's rings, do a compression test, follow this up with a cylinder leakage test, then compare the results!!!

Poor / old piston rings is my bet. Go to the mechanic, he will install new rings.

Will be expensive, but will save you money in oil.

Check for leaks also.

To even guess an answer we need to know:

What make and model?

What year of manufacture?

What mileage on the clock?

Is vehicle regularly serviced?

You either have a leak (check where you park) or its burning oil.

i have the same problem on my car almost every other week i have to put in two quarts and there is no leaks at all. what should i do?

If it is that bad it will need a rebore and new pistons

in simple layman's terms its knacked

bad rings and lifters