Subaru’s Octane Coverup: How a Major Automaker Failed to Fix a Systemic Engine Problem

In 2019, I purchased a Subaru Impreza advertised as taking 87-octane gasoline. The owner’s manual explicitly stated that 87-octane fuel should be used. Yet within months of ownership I had noticed that during low-RPM acceleration events the engine sometimes produced an unmistakable pinging sound: like the metallic rattling of a shopping cart rolling over rough asphalt.

To understand what I was experiencing it is necessary to understand the mechanics. Pinging, also called engine knock or detonation, occurs when the fuel-air mixture in a cylinder ignites prematurely or unevenly, rather than burning in a controlled manner from the spark plug. This happens when fuel auto-ignites from compression and heat before the spark plug fires, creating two simultaneous combustion events in the same cylinder. Critically, Subaru’s own owner’s manual acknowledges this: it states that owners “should not be concerned if your vehicle sometimes knocks lightly” but explicitly instructs drivers to “contact your Subaru dealer if you use a fuel with the specified octane rating and your vehicle knocks heavily or persistently.” My vehicle was doing the latter, on the specified fuel.

The Runaround Begins

I took my Impreza to multiple dealerships, but the timing worked against me. The COVID-19 plandemic meant technicians could excuse themselves from a ride along to experience the issue firsthand and they were unable to reproduce it. Undeterred, I persevered until I could demonstrate the problem to Subaru of Walnut Creek. Their initial solution was to apply Technical Service Bulletin 09-74-21R, which failed to resolve the issue. When that didn’t work they filled my car with 91 octane and told me to use 91 octane.

Let me be clear about what this means. The manufacturer advertised the vehicle for 87-octane fuel. The owner’s manual specified 87-octane fuel. Yet when that fuel caused the exact problem the manual warned about, Subaru’s solution was to tell me to use fuel with higher octane rating, fuel that costs more and contradicts their own specifications.

Subaru’s Advocacy Failure

Parallel to these dealership visits, I opened cases with Subaru of America. My customer advocate, Christen Weaver, asked me to get a second opinion. Then she ghosted me and never followed up. When I called the Subaru of America hotline from my main phone number, I either couldn’t reach an agent or they would hang up on me. This didn’t happen from my alternate phone number, a pattern that suggests systemic communication failure or deliberate obstruction.

I opened a second case using a different phone number and took my vehicle to another dealership for an independent assessment. The service manager rode along, confirmed the issue, but was honest about his limitations: there was no verified fix. That should have been the wake-up call for Subaru, but it wasn’t.

What happened next was insulting. Derek Klorig, who positioned himself as my advocate, claimed that “in reviewing with the Retailer, I have been advised your vehicle is operating as designed.” This statement was demonstrably false. The retailer had never told Subaru it was normal.

The Pattern of Deception

At this point, my frustration deepened when I considered Subaru’s track record with truth. The company is on record falsifying fuel economy and emissions test data at two Japanese factories, specifically at facilities that produce the Impreza, Crosstrek, WRX, and BRZ models sold in the U.S. The 2018 scandal revealed that Subaru had manipulated testing data going back to at least 2012, with evidence suggesting the practice may have dated back to 2002. Given that the company was willing to systematically cheat regulators, could I really expect them to be honest with customers?

The False Hope

My story took another turn when I received unsolicited spam from a newly opened dealership in the area. I took a chance and replied, asking if they would investigate. To my surprise, they did, and they went far beyond what Subaru’s other dealerships had done. They thoroughly disassembled my engine, walnut-blasted the intake, and installed new spark plugs, all under warranty. For a moment, I thought I’d finally found a solution.

This was no solution. They drained my full tank of 87-octane fuel, added just two gallons of 91-octane, and sent me on my way. The reality hit me as soon as I had filled up with a top-tier 87-octane gasoline: the pinging resumed immediately as I pulled out of the gas station. The expensive Tequila I’d given the technician as thanks suddenly felt like a waste, not because of their effort, but because their solution was merely a temporary workaround that proved nothing had been fixed.

Justice, Sort Of

Having exhausted every reasonable avenue, dealerships, service managers, Subaru of America representatives, and independent shops, I made the decision to pursue legal action. I sued Subaru of America for false advertisement. We settled for $4,500.

Four thousand five hundred dollars to make a systemic design flaw go away quietly. Subaru likely considered this cheaper than issuing a recall or actually fixing the problem.

The Broader Issue

During my research, I discovered I wasn’t alone. Many other Subaru owners report identical issues with 87-octane fuel, and I’ve heard this telltale pinging from other Subarus on the street. However, most drivers never notice it. The issue requires a specific combination of factors: low RPM acceleration, light throttle input, windows down, no music playing, and the awareness to recognize something is wrong. Most people simply turn up the radio and ignore it.

But Subaru knew. They had to have known, they have technical service bulletins about it, service managers confirming it, and data from multiple customer complaints. The company chose silence and deflection over accountability.