Zeitronix - Your Ultimate Tuning Partner

Award Winning Zeitronix Ethanol Content Analyzer

Best New Racing and Performance Product - Runner Up - SEMA 2009 and SEMA 2012


  • Real time display of fuel ethanol content from 0% to 100%
  • Displays fuel temperature in Fahrenheit and Celsius ranging from -40 to 125 F (-40 to 52 C)
  • Error indication in event of signal absence from Flex Fuel Sensor
  • Two analog outputs: Ethanol % and Fuel Temperature for use with datalogging or engine management systems
  • Surface mountable sleek aluminum enclosure with bright LED display visible even in direct sunlight
  • A flex fuel sensor is required.  The ECA is compatible with standard OEM sensors used in most vehicles with the flex fuel insignia or which run on E85
  • Dimensions: 2.8 x 1.8 x 0.75 inches (71 x 46 x 19 mm)

  • Made in the USA!
ECA Installation Instructions ECA YouTube Video Order Now

Note: A flex fuel sensor is not included with purchase of the ECA.  Sensors are standard components of many flex fuel vehicles and may be purchased separately at GM dealerships (GM part number 12568450 or 12570260) or directly from our order page.


We offer new Flow Through Flex Fuel Sensor as a part of ECA Kit, which includes the Ethanol Content Analyzer, Flow Through Flex Fuel Sensor and ECA Harness with a correct connector. ECA Kit can be purchased directly from our order page.
Note than connectors for Flow Through Flex Fuel Sensor and 12570260 Flex Fuel Sensor are different. We offer both styles.

What's your ethanol percentage?
The ethanol content of E85 fuel can vary from 60% to 92% ethanol. A fill up with E85 can drastically change the mix of fuel in your vehicle.  For performance drivers determining actual ethanol content of E85 is essential to maximizing an engine tune and horsepower.

Why know your ethanol percentage?
E85 has the equivalent octane rating of 105 octane gasoline.  Higher octane fuel is more resistant to knock allowing for more aggressive ignition timing, higher compression and increased engine power over gasoline itself.  The Zeitronix Ethanol Content Analyzer helps you get the most out of your engine and fuel.

Which vehicles have the flex fuel sensors?

A partial listing of vehicles with flex fuel sensors is listed below.  Newer
vehicles with the capability for using E85 also use flex fuel sensors.  Check for sensors with the following part numbers: 12568450 or 12570260.  A picture of the sensor is given to the right and dimensions of the sensor are also given below.

What are the sizes of the flex fuel sensor inflow and outflow lines?
Zeitronix Flow Through Flex Fuel Sensor both tubes are 0.37" and 0.5" at the flange.

12570260 flex fuel sensor tube sizes are as follows:
     Larger (outflow) tube:   0.37" and 0.5" at the flange.
     Smaller (inflow) tube:   0.31" and 0.44" at the flange.

The usual mounting location for the sensor is the return fuel line.
Always check for fuel leaks.

ECA Analog Outputs
Ethanol content and temperature analog outputs are available as part of the ECA.  The flex fuel sensor does not provide these outputs.  We have created the ECA to provide these outputs making use of E-85 easier with after market engine control modules and data logging systems.

Analog Outputs  Signal Range
Ethanol Percentage 0-5 Volts 0% to 100%
Fuel Temperature 0-5 Volts -40 to 125 C (-40 to 257 F) 

Ethanol % = 20 * Voltage  Fahrenheit Temp. = -40 + 59.4 * Voltage Celsius Temp. = -40 + 33 * Voltage

12570260 Flex fuel Sensor Technical Specification:

Measuring range: 0100% Alcohol (ethanol) in fuel mixtures 
Sensor Accuracy: 5% of the mixture ratio 
Output characteristic:  Linear
Operating temperature: Environment -40C +125C, Fuel -40C +90C 
Maximum fuel pressure:  10 bar, (145 psi)
Maximum pressure drop:  0.1 bar, (1.45 psi) 
Maximum flow:   200 l/h 
Supply voltage:  618 Volts DC
Sensor Temperature error:  < 1.5% 
Response time:   < 250 ms after power on at any temperature
Design:  Suitable for the installation in motor vehicles, independent of position.  Housing is waterproof.   Flex fuel sensor Dimensions are given below.

Vehicles with GM 12570260  flex fuel sensors compatible with the Zeitronix Ethanol Content Analyzer:

Trucks with an E85 Flex-Fuel Option:

2000-2002 GM 2.2L Chevy S-10 2WD pickups
2000-2002 GMC 2.2L Sonoma 2WD pickups
2000-2002 ISUZU 2.2L Hombre pickup
2000-2005 GMC 5.3L V-8 Sierra half-ton pickups 2WD & 4WD
2000-2005 GMC 5.3L V-8 Silverado pickups
2003 Chevrolet 5.3L Avalanche 4-door pickups
2004-2005 Dodge 4.7L Ram 1500 series
2005 GMC 5.3L (Vortec) Avalanche
2005 Nissan 5.6L V8 DOHC
Minivans with an E85 Flex-Fuel Option:
1998-2003 Chrysler 3.3L Town & Country minivans
1998-2003 Plymouth/Chrysler Voyager minivans, 3.3L
1998-2005 Dodge 3.3L Caravan & Grand Caravan SE minivans
2003 Dodge 3.3L Cargo minivans (all)
Passenger Cars with an E85 Flex-Fuel Option:
2003-2004 Chrysler 2.7L Stratus sedans (all)
2003-2005 Chrysler 2.7L Sebring sedans (all)
2003-2005 Mercedes 3.2L C320 sport sedan and wagon
2005 Mercedes 2.6L C240 sedan and wagon (all)
Sports Utility Vehicles with an E85 Flex-Fuel Option:
2002-2005 GM 5.3L (vortec) Suburban SUVs (all)
2002-2005 GM 5.3L (vortec) Tahoe SUVs (all)
Fleet 2005 GM 5.3L (vortec) Tahoe police package
2002 GM 5.3L (vortec) Denalis (all)
2002-2005 GM 5.3L (vortec) Yukon & Yukon XL SUVs (all)

Where is the sensor located?
The sensor is mounted as part of the fuel line.  Below is a partial list of vehicles and locations to find the sensor.
2000 - 2002 Chevy S-10 2.2L Passenger side, front frame rail, behind wheel well
2000 - 2002 GMC Sonoma 2.2L Passenger side, front frame rail, behind wheel well
2003 Chevy S-10 2.2L Passenger side, front frame rail, behind wheel well
2003 GMC Sonoma 2.2L Passenger side, front frame rail, behind wheel well
2002 - 2005 Chevy (Trucks, Suburban, Tahoe) 5.3L Mounted to frame directly under drivers feet
2002 - 2005 GMC (Trucks, Yukon, Tahoe) 5.3L Mounted to frame directly under drivers feet

What are the sensor dimensions?
Units are in millimeters.