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The Garage Professor finds out what people think about oil change intervals and provides a brief introduction.

Note: Improvements in performance depend on the vehicle, it’s condition and how it’s used. This video is not intended to imply that all users will experience the same performance gain by upgrading to Royal Purple.


Announcer: Beginning in Chicago and winding its way to LA, Route 66 ends at the Santa Monica Pier in Los Angeles, and the Garage Professor is there to talk to you about the slippery slope of oil change intervals.

Sandy: Welcome back to the garage. Today we hit the sleek streets to see what you think about oil change intervals and learn that everybody has their own idea as to what they think it's right. Let's hear what folks have to say before we flush this out.

Sandy: Do you change your oil every 3,000 miles?

Male 1: No.

Sandy: Who changes their motor oil every 3,000 miles?

Female 1: I do.

Male 2: We're supposed to.

Female 2: No.

Sandy: Do you change your motor oil every 3,000 miles?

Female 3: I do. I try to actually every two months because I drive a lot.

Sandy: Do you change your oil every 3,000 miles?

Male 3: I do.

Sandy: 5,000 miles?

Male 4: No.

Male 5: No. We just don't.

Sandy: You guys are non-oil changers.

Male 6: I go around 4,000 miles, 4,500.

Sandy: Most professionals agree 3,000 is too frequent of an oil change interval. They say 5,000 to 7,000 is more realistic. And if you see those two guys broken down on Route 66 you'll know what happened to their engine. Let's take a look at the next question.

Sandy: Your son just turned 16 years old. You find out that he's watched every "Fast and Furious" movie that they ever made and by that time there's probably "Fast and Furious 30", who knows. He just watched every "Fast and Furious" movie that you had on DVD. He crawled under your bed, found your hidden stash of "Fast and Furious" stuff.

For the story, let's go "Fast and Furious". He then goes, "Hey mom, let me borrow the keys to your sports car. You toss him the keys. He comes back eight hours later, sweaty-like and nervous. When he gives you the keys back, do you run and get your motor oil changed or do you just say it's probably fine?

Male 7: He'd get in trouble. I would look at my tires. I would be more worried about my tires than I would be about my oil.

Sandy: Four bald tires?

Male 7: Yes, yes. See if he's doing some drifting, whatever.

Sandy: Now, since you borrowed her car and did who knows what, would you change your mom's oil?

Male 8: No. I would just make sure the car is in one piece.

Sandy: And clean.

Male 8: Clean, definitely. I'm OCD so I'm always clean.

Sandy: If you lent your car to someone who just watched every "Fast and Furious" movie, you know they were red lining, running nitrous, burning rubber. Get your oil changed. On to the next question.

Your car has a computer system that tells you when to change your oil. Do you believe it's accurate?

Male 7: I don't think so, no. I know the car can handle going farther.

Sandy: Okay. All right.

Male 9: No.

Male 10: I would say yeah.

Sandy: Man, it's like Laurel and Hardy here. All right. So what you're saying is you believe that the computer is always right, and you have some distrust in the machine.

Male 9: Always distrust the machine.

Male 10: Right on.

Sandy: Do you believe that it's accurate in telling you to change it at the right time, or is it just a best guess?

Female 4: No, I think it's a best guess, just estimating around where you should be changing your oil but you should know your car a little bit more to change it. Yeah.

Male 8: I think it's close to accurate, at least.

Sandy: At least close.

Engine oil monitoring systems use software derived estimates and they're generally a good starting point, but they can't know the condition or type of oil in your engine. They're merely doing a best guess based upon many preset software parameters. Now let's hit the next question.

Sandy: Which do you change more often, your motor oil, your computer password, or your bed sheets?

Male 11: Probably more often bed sheets.

Sandy: That's correct. And your wife thanks you.

Male 11: Yes, she does. She actually does it, and we both help.

Male 7: Bed sheets.

Sandy: You are correct.

Male 9: Bed sheets.

Sandy: Okay. Let's hear your opinion.

Male 10: Computer password.

Sandy: Computer password?

Male 10: Yeah.

Male 9: Bed sheets.

Sandy: Which do you change more often your computer password, your motor oil or your bed sheets?

Female 5: Your bed sheets and motor oil.

Sandy: I don't know where that's going but as long as the bed sheets are your priority, we're okay.

Female 5: Okay, yes, they are.

Sandy: While the number of miles on your bed sheets may vary, the number of miles allowed between oil changes will depend upon your vehicle, its condition, the way you drive, and the oxidation stability of the motor oil.

Oxidation stability can be measured by the ASTM's rigorous thin film oxidation update test, the TFOUT test. This test is so severe, it lasts 1,300 minutes. Conventional motor oils typically last less than 300 minutes. Ordinary synthetic motor oils last less than 500 minutes. And Royal Purple's HPS Motor Oil has been shown to outlast the entire duration of the test.

If you have any questions about your specific oil change situation, hit up the oil manufacturer, engine builder, or your online automotive community. And be sure to read your service manual. They can all help keep things running smoothly. That's our brief introduction to oil change intervals. Be sure to catch us next time in the garage with the Garage Professor.

Announcer: And for more information go to