"They don't like me," Robinson says. "They make life very difficult for us."
America's official testing agency for gas-saving devices is the Environmental Protection Agency. It has tested 109 so-called gas savers.
"The devices and the additives that we have tested just don't work," says Margo Oge, director of the EPA's office of transportation and air quality. "We have been doing it for 35 years, and we have seen pretty much everything that you can imagine."
This is not to say there's nothing you can do to save on gas.
Some NASCAR fans told us they use upper-grade gas because they say it gives them a little bit better mileage, more power and a cleaner engine.
But that's a myth, one of many debunked in "20/20's" new book, "Myths, Lies and Downright Stupidity."
Lots of people are fooled. Just this week, cops arrested eight men for allegedly passing off regular gas as premium at New York gas stations. They were caught only because investigators wiretapped the suspects -- the customers never noticed enough to complain.
Some older cars need higher octane. And cars with high-compression, high-revving engines need higher octane gas to run smoothly. But most don't.
Check your owner's manual -- 90 percent of today's new cars have low-compression engines. They don't need high-octane gas, and you're wasting your money if you buy it.
Now once you've figured out which octane to buy, does the brand matter? No. All the gas, brand name and no name, comes from the same refineries.
Even NASCAR driver Jimmie Johnson knows the truth. "It's a myth, you don't need the name-brand stuff."
And, whatever gas you use, here are some tips from Consumer Reports:
Make sure your tires are properly inflated. One that's low on air uses more energy to push the car down the road.
Roll the windows down -- turn off the air conditioner. Some people believe that at highway speeds, there's so much drag from an open window that you'd save gas by putting the windows up and using the air conditioner. But that's a myth. Consumer Reports ran tests and found that at any speed, using the air conditioner burns more gas.
Slow down. Don't accelerate suddenly. You save the most gas by driving smoothly.