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Dale Investigates: Diesel Dilemma


Going to the gas tank is something most of us do all the time. We usually don’t think much about what we’re doing. But it pays to pay attention. If you accidentally start pumping diesel into your gasoline powered car, you’re in for some expensive repairs. And if you pump gasoline into a diesel engine, the damage could be even worse! Mixing up the two pumps may be easier than you’d think.

Diesel and gasoline at most gas stations used to be dispensed at completely separate pumps. There was almost no chance of mixing up the two. You would have to drive up to the wrong pump, which is pretty hard to do without noticing.

Recently, new pumps have been showing up that dispense diesel and gasoline from a single unit. To get diesel or gasoline you just have to hit the button for the type of fuel you want and pick up the right nozzle. But if you’re not paying attention, you can select the wrong fuel and nozzle without noticing it.

To make it harder to mistake the two fuels, most gas stations have taken a few safety measures. First, gasoline nozzles are a standard black color, while diesel nozzles are usually bright green. Second, most diesel nozzles won’t even fit into a gasoline tank, making it almost impossible to start pumping diesel into your gasoline car.

Unfortunately for one consumer, an Exxon station in southwest Atlanta was lacking those safety measures. The diesel and gasoline dispensers had nearly identical nozzles. Both were covered with black rubber and both were exactly the same shape and size.

This unfortunate consumer pumped a full tank of diesel into her gasoline powered car and suffered the consequences: a broken down car and a $500 trip to the mechanic.

What Happens When You Mix Up Diesel and Gasoline?

Putting diesel into your gasoline powered car is bad news. And once you’ve done it, there’s really nothing you can do to save the situation. A gasoline powered car may seem to work for a bit with a tank full of diesel, but that’s really just the car burning off the last of the gasoline still left in the gas lines. As soon as that diesel hits the gasoline engine, the car will stop working.

Repairs for this kind of mistake are not cheap. They an run anywhere from $500 to $1,000. All of the diesel needs to be removed from the vehicle. That means removing the gas tank to empty it and clean out any diesel residue. It may also mean removing and cleaning the gas injectors if they can’t be cleaned by flushing them with gasoline.

If you’ve accidentally put gasoline into a diesel engine, the damage could be even worse. That’s because in a diesel engine the diesel acts not just as fuel but also a lubricant. The gasoline will very quickly strip out all the lubricant and without it the diesel engine will seize up, completely destroying the engine.

Making it Right

TrustDALE reached out to Exxonmobil and to the gas station to try to resolve this issue. 

It turns out, there are no regulations that cover how side by side diesel and gasoline dispensers should be marked. In fact, there are no official standards, though at most gas stations there is a visible difference.

In this case, the gas station and their fuel distributor did the right thing. The gas station quickly replaced the tricky black diesel nozzles with the more usual green covers. As for the damage to the consumer’s car, Clipper Petroleum, the fuel distributor that sells fuel to this gas station, made it right and paid for the repairs.

According to Bo Bearden of Clipper Petroleum, this problem is thankfully not too common. But there are steps that can be taken by gas stations to help prevent it, and in this case those protections were missing.

If you have a consumer issue that isn’t being resolved, you can contact