Have her FILL the tank and write down the mileage. The next time she gets gas have her FILL it again and write down the mileage. Then divide the miles traveled by the gas used to see what the gas mileage is. Do this several times. The type of driving city or highway will make a big difference. Also if she has a lead foot the mileage will suffer. The gas mileage can suffer for many reasons. It canbe as simple as a dirty air filter or much more complicated. All vehicles will decrease in fuel mileage if they are not properly maintained (tune ups etc.)

If you can't get a service history from the previous owner you need to find an honest mechanic to check it over and decide what it needs at this time if anything. If you have the owners manual it tells when services are due such as spark plugs, air filter etc. Keep a log of what is done to the vehicle and then you will know when it is due for maintenance in the future.

Most auto stores like Advance, Auto Zone, & OReilly can test the battery and alternator for you if you take the vehicle there.

 

I agree with one of the postings, sell it; as much as she loves it, as I do my blazer, she won't be able to afford all it's problem's down the line( I do my own work, so that's my excuse for keeping mine...for now)....sell it!!!