When you get your oil changed, what can you do to make sure you're getting the right stuff? A Kane In Your Corner investigation found some oil change establishments may be using substandard oil, or simply oil that's the wrong grade for your car. So News 12 New Jersey's Walt Kane spoke to everyone from experts to viewers themselves, to come up with tips that might help make the process a bit safer.

Experts and viewers alike agree the key is finding a mechanic you trust. "I've known my mechanic for 10 years," says Chris Henwood of Long Valley. "My car has 310,000 miles on it so I have to believe he's doing the right thing."

Experts say you should also know what oil your car requires. You can usually get a clue by looking at the oil cap, but more complete details can be found in the owner's manual. 

But it's equally important to find out what's actually being put in your car. Regulations passed in 2013 requiring New Jersey oil changers to provide receipts showing the brand name and viscosity of oil used have never been enforced, so experts say customers should not be afraid to ask.

"I would want them to document what they were putting in my car," says Tom Glenn, president of the Petroleum Quality Institute of America. If they won't, Glenn says, "I would drive through the bay and out the other way."

Some viewers offered more extreme steps to ensure the quality of the oil they receive. A few said they take their own oil to their mechanics. But if you try that approach, don't expect a big discount. Mechanics buy oil in bulk much more cheaply than consumers can purchase it by the bottle, so the oil change will likely cost full price, or close to it.

Finally, some viewers, like Jason DeLaCruz of Long Branch, say they change their own oil. "I know exactly what I'm putting in, how much I'm putting in and the service I'm getting," he says.

However, changing your own oil is not risk-free. A 2013 Kane In Your Corner investigation found some bottled oil for sale in New Jersey was unsafe for most cars; some appeared to be used oil that was simply being resold. Based on those reports, the state conducted its own tests and banned 19 brands of motor oil last year. If you do buy your own oil, experts advise to look for a brand that carries the seal of approval of the American Petroleum Institute.

Kane In Your Corner went undercover to seven garages and asked for oil changes. They also gave the garages sterile containers, which they requested be filled with the same oil being put in the car. Samples of the extra oil were sent to an independent lab for testing. 

One garage completely passed the test. Test results indicated the oil was 5W-30, the grade specified by the manufacturer. The PQIA says the oil also contained appropriate anti-wear additives.

Four garages gave oil that the tests indicated was not 5W-30 but otherwise contained the proper additives. Three had provided receipts saying they supplied 5W-30 oil, but lab tests indicate they actually did not. 

Two garages provided oil the PQIA deemed "not suitable" for most cars. Lab tests indicated these samples were low on anti-wear additives, which the PQIA said could potentially cause premature engine failure if used over time. These oils also had cold-crank viscosities that significantly exceeded 5W-30 by so much that the PQIA indicated that could also cause engine problems, especially in colder weather.