What if I accidentally put regular gas in my Mercedes?

Even the birds in the trees know that Mercedes vehicles run on premium fuel. Here’s another truth: most folks are no strangers to accidents of this or that sort. Anyway, let’s say you’re “sporting” a Mercedes and you’ve put regular gas inside it. What happens next?

Since you’re reading this, we guess that you’re no stranger to accidents, too. If the above scenario happened to you, don’t worry. We’ve got nothing but comforting information for you. In other words, today, we’ll talk about what happens if you accidentally put regular gas in a Mercedes. Stick around for some useful pieces of info!

You’ll be happy to know that nothing will happen if you put regular gas in your Mercedes. If we’re talking about an “accident”, that is. Anyway, you might notice a slight decrease in performance but that’s it. No damage to the engine. Just don’t make a habit of sipping regular gas inside a premium vehicle. 

What happens if you (accidentally) only read the snippet? Whether it’s an accident or not – you’ll miss out on some valuable stuff. Therefore, read the whole thing!

Table of Contents

What kind of gas does a Mercedes take?

Before we get to the main section, let’s consider some basics first. That being said, it’s only natural that we ask what kind of gas a Mercedes takes. So, shall we hear the answer?

Here’s the thing: Mercedes-Benz vehicles only run on high-octane or premium gasoline.

Usually, premium gas has an octane rating between 91-94. The higher the octane rating, the slower gasoline will burn. Therefore, you should only sip premium gasoline inside a Mercedes. Fuel with a lower octane rating will cause your pistons to fire too quickly. That will eventually result in sometimes irreparable damage to your engine.

But, we’re getting ahead of ourselves here. Let’s check if there are other “basics” we’d like to tackle.

Do all luxury SUVs require premium gas?

Of course, not all Mercedes-Benz vehicles are SUVs. However, nothing stops us from tackling this question nevertheless. The simplest answer reads: NOPE, not all luxury SUV vehicles require premium. Still, the majority of them – do.

Many folks immediately think that a luxury car demands you use premium fuel. This is what people call a common misconception. Also, many people will buy premium just because they have a luxury car. Not because they’ve read the owner’s manual, no. That’s a mistake.

All in all: check out your vehicle’s owner manual. If it suggests you use premium, use premium. Otherwise, don’t spend some good money buying premium. That’s because you’d be gaining nothing instead. Sipping premium inside a regular car is a waste of money.

If you’re curious to know a bit more about the subject, we’ve written about it. Click on this link to read up on the benefits of using premium gas. Oh, it seems we’ve got another one here!

Why do luxury cars take premium?

We’ll try to be quick here. The reason why most luxury vehicles require premium lies in the following:

  • Premium vehicles are made to function with premium gasoline. It helps the function at higher fuel efficiency. Also, it maximizes their speed and overall performance. In other words, it helps them reach their full potential.

To repeat: only use premium gas if your owner’s manual says so. Now that we’ve considered “the basics”, let’s dive deeper. Shall we answer the main question: what if I accidentally put regular gas in my Mercedes? We’ll find out together!

A Mercedes car, inside which regular gas was put.

What if I accidentally put regular gas in my Mercedes?

Okay, so we kinda implied earlier that you’ve got nothing to worry about. Of course, such a statement requires some elaboration. So, shall we finally see what’s it all about?

Anyway, putting regular (octane 87) gasoline won’t damage your Mercedes-Benz. If it’s a one-time thing, that is. Well, nothing would happen if you do it a couple of times more. However, keep in mind that you shouldn’t make a tradition out of it. Long-term usage of regular gas with a premium vehicle isn’t recommended.

So, what happens if you accidentally put regular gas inside a Mercedes? Nothing much. You’ll probably notice a slight decrease in performance. Also, you’ll probably witness a drop in fuel economy. Once you refill your gas tank with high-octane fuel, the whole thing should go back to normal. If you’re too sensitive about it, just top the fuel tank off with premium after a little usage.

What if you fill an empty Mercedes fuel tank with regular gas?

Good question! If your gas tank was empty, you might experience certain issues. Once again, don’t worry, as it’s not that bad. The thing is that you’ll probably “enjoy” some engine knocking on acceleration. Now, the system will modify ignition timing to minimize it.

Let’s consider what would happen if it was the other way around. So, we can say that your tank was more than 1/2 full with premium. You top it off with regular, octane rating 87 gasoline. What happens? Almost nothing (you’ll notice no issues concerning drivability).

So, shall we give something of a conclusion here? As you could’ve read, nothing bad will happen if you sip a little regular gas inside a Mercedes. Now, if you were to make a tradition out of it, as we suggested you don’t… Yeah, let’s see what will happen!

The effects of long-term regular gas usage in a premium vehicle

Here we’ll consider what will happen if you “make a tradition out of it”. First things first, you should know that such an activity will harm your warranty. It might leave you without insurance if something was to go awry. However, let’s talk about something that’s more serious!

If you get used to sipping regular gasoline in a premium vehicle, here’s what can happen:

  • It might cause frequent engine knocking.
  • It can damage the pistons. 
  • It can damage the valves. 
  • It can damage the spark plugs. 

Now, there’s a good chance that you won’t hear the knocking. That’s because of the knock sensors’ ability to retard the spark timing. Still, that doesn’t make the other three issues look less frightening. Okay, that might be too much of a word. But, you get the point, right?

So, shall we see what happens if it was the other way around?

The effects of long-term premium gas usage in a regular vehicle

Here’s the simplest answer: this will do more damage to your wallet than your vehicle. That’s right, using premium gasoline won’t damage your engine at all. However, you should know that it won’t boost your vehicle’s performance either. You’ll be paying more for no reason.

Since we’re talking about money and everything, here’s a suggestion. Maybe you can try driving a Tesla and save some gas money? Just a suggestion, no need to get mad.

Wait, do some folks clean their engines with premium gas?

Even though some people speculate this, it just doesn’t work. Octane rating has absolutely nothing to do with engine cleaning. If you want to prolong the life of your engine, there’s other stuff you can do. For instance, you can regularly change your oil. Or, you can schedule service appointments every once in a while. Speaking of a vehicle oil change, here’s an article you’ll want to read.

How can you tell if it’s time for an oil change?

So, we’ve mentioned that changing your oil every now and then can preserve your engine. Therefore, it might be good to show you the signs that might inspire you to do so. Here they are!

Let’s say you’ve smelled oil inside your car. If so, there’s a chance that your vehicle’s experiencing an oil leak. Or, you might notice that your car smells of gas. If that were to happen, don’t hesitate to schedule maintenance immediately.

Here’s another sign that you need an oil change. It’s when you’ve driven your vehicle for 3000 miles without an oil change. Almost all experts will tell you the same. We’re talking about the following sentence: change your oil every 3000 miles.

Also, is your “Check Engine” or “Oil Change” light flickering, by any chance? Yup, the latter’s much too obvious. However, both lights can indicate that your car needs an immediate oil change.

Now, here’s the last sign your vehicle’s in desperate need of an oil change. You’re hearing some engine noise and frequent knocking. This might mean that your engine parts are lacking lubrication. The oil acts as a protective layer between your engine’s parts.

PS. Maybe you’re running your car on bad gasoline? That might also cause the engine noise and knocking. To learn how to test for bad gasoline, follow that link.

Final words

Alright, dear folks, that’s about all there’s to say about today’s subject. We’ve talked about what happens if you accidentally put regular gas in my Mercedes. Now you know you’ve got nothing to worry about. Just don’t make a habit out of it. It’s for your vehicle’s good.

If you’re on the lookout for more tips on various gasoline-related topics, click here. Until next time!