How to know if petrol pump is dispensing highly adulterated or phase separated petrol?

Below are the suggestions given by AI, but other than this, if you have any other tips on how to detect adulterated or phase separated petrol, please share in this thread.

AI suggestions

Because ethanol binds with water and drops out of the petrol mix, it fundamentally changes the weight and behavior of the liquid. This changes what appears on the digital screen in very specific ways.

1. The Fluctuating Density Number (The Biggest Red Flag)

Modern fuel dispensers continuously recalculate and display the live density of the liquid flowing through the pipe.

The Normal Behavior: When the pump starts dispensing, the density value should lock onto a steady number within 2 to 3 seconds (e.g., 742.5) and stay flat.

The Red Flag: If you see the density reading constantly fluctuating, jumping wildly, or drifting down by more than 3–5 units while the fuel is flowing, stop the refueling. This happens when the nozzle draws a chaotic, unstable mix of pure petrol and pockets of water-ethanol phase sludge from the bottom of the underground tank.

2. Check for an "Implausible" Density Value

Pure petrol has a specific weight range, but water is much heavier, and pure ethanol has a different density.

The Normal Range: In India, E20 petrol must read between 720.0 and 775.0 kg/m³.

The Red Flag: If the electronic screen displays a density above 780 kg/m³, it is electronically tracking a high concentration of water. If it reads below 715 kg/m³, it indicates potential phase separation where the heavier ethanol-water mix has settled to the bottom, leaving an unnaturally light, low-octane top layer of petrol.

3. Stuttering or Jerking of the Digital Litres Counter

Automated fuel dispensers use an electronic pulser linked to a physical flow meter. Petrol flows smoothly, but water and separated chemical layers have a different viscosity.

The Normal Behavior: The digital numbers counting the total litres and total price must advance in a smooth, continuous, blazing-fast blur.

The Red Flag: If the flow of digits looks stuttery, flickers, or physically pauses/slows down for a fraction of a second before rushing forward again (while the attendant is holding the nozzle trigger wide open), the flow meter is hitting dense water-sludge pockets.

4. Look for the "Preset Error" or "Flow Timeout" Message

If an underground tank accumulates a significant layer of water at the bottom, it triggers an emergency alarm on the station's indoor console (the Automatic Tank Gauge system). This system usually attempts to cut off the outdoor dispensers.

The Red Flag: If you pull up and the small auxiliary text line on the dispenser screen reads "ERR", "COMM FAULT", or "FLOW TIMEOUT", it means the pump's computer is fighting an automated safety lock triggered by tank contamination. If the attendant clears the error manually or restarts the machine to proceed, refuse the fuel.

5. Water Accumulation Over Underground Tank Caps

Before pulling up to a nozzle, glance at the driveway ground where the heavy metal, circular underground tank lids are located.

The Normal Condition: The ground surrounding the metal tank access plates should be completely dry, clean, and well-graded to allow rainwater to run off.

The Red Flag: If you spot standing water, deep muddy puddles, or a steady trickle of water pooling directly over or leaking into those underground access plates, moisture has almost certainly breached the rubber seals and contaminated the fuel below.

6. Tanker Truck Actively Unloading Fuel

Look around the station property for a massive fuel delivery truck connected to the underground fill points.

The Normal Condition: Refueling should only be done when no delivery trucks are present, or at least 20 minutes after a delivery truck has completely finished unloading.

The Red Flag: If a water tank truck or fuel tanker is actively dumping thousands of litres of fresh fuel, the high-pressure flow violently stirs up any dormant water pockets, condensation, or debris resting at the absolute bottom of the station's tanks, pushing it straight into your vehicle's nozzle.

7. Fresh Digging or Unpaved Mud Near the Property

Scan the outer perimeter and corners of the station grounds where the underground reservoirs are buried.

The Normal Condition: The entire station layout should be paved with concrete or asphalt blocks to prevent soil erosion and water logging.

The Red Flag: If there is active construction, unpaved muddy paths, or fresh digging directly adjacent to the fuel tanks, heavy rainwater or rising groundwater can easily seep through cracked subterranean bricking and flood the fuel supply.

8. Total Absence of Customer Volume

Observe the general activity and traffic flowing through the station lanes.

The Normal Condition: High-turnover stations keep a constant stream of vehicles moving through, ensuring the fuel in the tanks is refreshed daily.

The Red Flag: If a station looks completely deserted, features rusty equipment, or sits empty for hours, the fuel is stagnant. Stagnant E20 fuel is a prime candidate for phase separation, as it has ample time to absorb ambient atmospheric moisture from the underground tanks.