I think my friend did this and I believe her car broke down. We were driving in her car and shortly after she stopped to fuel up the car broke down and she said that was the reason. But given everyone else's responses that was probably her case only. So maybe dont worry, but that's what happened to my friend.

What year is the car? For newer cars they just recommend premium. You might get lower HP output. Older cars like my 2004 Acura rsx require 91 or else it will knock.

Anonymous wrote:I had to put regular gas in my car today because I was on E and there was nothing else left

How bad is this? And what next steps should I take

Did you fill it all the way up?

If it's only part way filled, then the next time use the really high octane stuff and they'll mix together and average out.

Or not, this is just a guess. I drive cheap cars that are fine with regular.

Anonymous wrote:

Anonymous wrote:Unless your car has a diesel engine, I would not worry about it.

Ha! My ex-stepmother put diesel in her regular car and it took $thousands to fix.

An attendant did that to my car in Europe. It cost $70 to get it all cleaned. Car still runs after 15 years, and was bought used. Go Mitshu!
By the way, the nozzle was too big for the opening (for a reason), but a gentleman helped her poor it from the air. I was inside buying something and didn't notice til next day when the gas had run out and it was time for diesel to hit it.

If your car doesn't knock it's fine.

I had an Acura TL where the owner manual said to use only premium gas. I never used premium, only regular. Car lasted 18 years with no engine or transmission problems; it died only when someone rear-ended it.

Regular gas should be just fine. No need to do anything, IMHO.

I'm glad I drive a 10 year old Chevy with 200,000 miles on it, it could care less what octane I use!

One tank isn’t cause for concern. You might notice knocking or diminished performance in engines that require premium, but one tank won’t do any real harm.

Don’t make a habit of it though- because that WILL do harm over time. Knocking (pre-detonation of fuel in high compression engines) will cause valve seal erosion and loss of engine compression. You’ll ruin the motor if you do it all the time.

Anonymous wrote:Just add an octane booster, you get it for approx $10 from local auto store

This is what we did for our car.

OR... 87 will be fine for one tank. you don't need the octane booster

Anonymous wrote:Just add an octane booster, you get it for approx $10 from local auto store

This. Lots of gas stations sell it too. One time at a we serve station the guy gave me regular by mistake, the solution was just pouring in a bottle of booster.

Just add an octane booster, you get it for approx $10 from local auto store

Yes, mine too! OMG! My Elantra is like, yuck this caviar!, where is my stale bread!

As long as you use some grade of gasoline, you will be fine. I don't think there's a car made in the last 25 years that wouldn't automatically adjust when using a lower octane gas. Perhaps lower performance or slightly lower fuel economy until the next fill up and my guess is that you will not even notice.

https://www.thedrive.com/cars-101/36538/what-happens-when-you-put-regular-gas-in-a-premium-car

I will dispose of it for you. Let me know where I can pick up the keys.