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eFlexFuel E85 flex fuel conversion kits


Starting at $61.50 / month with Affirm logo

Truspilot consumer rating SKU: U-EF-PLUS Availability: In stock
  • Free shipping
  • Delivery time 2-5 days
  • 5 year warranty with registration
Fully Automatic Flex FuelAlways Optimized Fully Automatic Flex Fuel
Cooler & Cleaner EngineCooler & Cleaner Engine
No Tuning NeededComplete System, No Tuning Needed
Increase PerformanceUp to 10% Increase in Performance
Flex Fuel System VerifiedYour Fuel System Verified

+ Why to use E85?

  • Bioethanol E85 is the lowest cost fuel available in the market. You can save up to 50% on your fuel costs.
  • You are driving with locally produced renewable fuel. Your carbon footprint goes down by up to 80%.
  • You can increase your vehicle’s horse power up to 20%.

+ How do you know my vehicle is compatible?

We always ensure that your vehicle is compatible with the eFlexFuel system. In addition, we check that the vehicle's components, such as the fuel pump, injectors and fuel lines, are resistant to E85.

+ Where the more power and torque comes from?

  • Automatic engine tune adjustment optimizes the engine in real-time to match the fuel blend.
  • E85 has 100+ octanes that supports higher compression ratios and greater ignition advance.
  • E85 contains a great deal of oxygen for burning: the fuel burns more completely producing more power, less harmful emissions and a cooler engine.
  • eFlexPro with its fully customizable fuel maps enables precision engine tuning on E85 resulting in up to 20% horsepower gains.

DIY Virtual Load Sensor Tuning

Easily & safely create custom ethanol fuel maps based on your own vehicle's performance & modifications, without tapping into external load sensors - all from your laptop. Now you can augment your Ethanol fueling yourself, without touching your factory ECU and without jeopardizing engine safety.

Experience the VelvetTouch+

All eFlexFuel devices provide smoother and more seamless drivability than any other flex fuel system in existence. No small feat, our R&D team accomplished this with unrivaled attention to detail, countless long days & late nights, and a unique eye for optimization. The result of this "Velvet Touch" development? Our class-defining eFlexV10+, eFlexPro 2 & eFlexPlus.

Supercar Technology in your Daily Driver (or Weekend Warrior)

By installing the eFlexFuel kit, you're in good company. eFlexFuel conversion kits utilize technology found in the Koenigsegg Jesko, Dodge Challenger SRT Demon 170, and other top-tier performance vehicles. This tech is used to get the most out of E85, Gasoline, or whatever blend of the two you have in your tank.

Industry Leading, Free 5-Year Warranty (With product registration)

Nothing says, "We stand behind our product," like our free 5-Year warranty. We know what our kits are made of and we aren't afraid to put our money where our mouth is. You will not find a warranty like this anywhere else.

Expertly Engineered, Designed & Manufactured in Finland

Expertly Engineered, Designed & Manufactured in Finland. We have developed our hardware & software in-house in Pirkkala, Finland, since day one. Before shipping, we confirm every single control unit's functionality before shipping.

Technical Specs & Features

  • Precise Ethanol Content real-time measured over 100 times per second
  • Advanced signal processing filtering system in all input signals
  • Shock-Proof & Weather Proof casing
  • High Quality Wiring Harness with snap in connectors (no soldering required)
  • Ethanol Tested & Approved fuel accessories (line, clamps, quick-connectors)
  • Bluetooth 5.2

eFlexApp Main Features

More eFlexApp Features

Please confirm device versions features at eFlexApp page

eFlexTuner Main Features

More eFlexTuner Features

Please confirm device versions features at eFlexTuner page


Dyno results

Peak power gains do not always tell the whole story! It's important to look at power gains across the entire RPM range / dyno curve, A.K.A. power "under the curve." Power gains under the curve will have a greater impact on driving experience. This is because gains under the curve impact the broader usable powerband, whereas peak power is momentary - only at one point in the RPM range.

If peak gains are 5% while max gains under the curve show 20%, this +20% increase is a better reflection of how your driving experience will change (you'll certainly feel that increase!). You want to feel the difference in the seat of your pants, and this is where power under the curve plays usually the biggest role.

+ Compare products

Free 5-Year Warranty (with registration)
Ethanol Content real-time measured over 100 times per second
Advanced signal processing filtering system in all input signals
Shock-Proof & Weather Proof casing
High Quality Wiring Harness with snap in connectors (no soldering required)
Ethanol Tested & Approved fuel accessories (line, clamps, quick-connectors)
Bluetooth 5.2
Analog Wires for External Sensors
Ethanol content
Vehicle speed
Engine RPM
Duty cycle
Fuel temperature
Ambient engine temperature
Injector activity
Cold enrichment
Device status
Driving mode selection *
Cold enrichment custom setting (created with eFlexTuner) *
Save RPM based enrichment with driving mode selection (created with eFlexTuner) *13
eFlexPro view for analog data
RPM. based 2D fuel map *
Fault codes
Data logging
Fuel map adjustment
Log file analysis
3D fuel maps
Sensor linkage
Cold start adjustment
Virtual Load Sensor Tuning

* Does not include in eFlexV10+ devices.

+ What's included

  • Control unit (3” x 5 1/5” x 1” in) x 2
  • Ethanol sensor
  • Wiring harness specific to your vehicle with an external temperature sensor x 2
  • Two additional analog inputs that plug in to the engine’s own sensors (MAP, MAF, TPS or WBO) - included only in eFlexPro
  • Cable ties
  • Male fuel injector connectors x 2
  • Fuel hose
  • Fuel line quick connectors
  • Fuel line disconnect tool
  • Hose clamps
  • Installation and User Guide

+ Installation

  • Installation info
  • General Installation and User Guide is included in the product package.

+ Returns

We always verify compatibility of the purchased product with the customer’s vehicle, so you don’t need to return or exchange your kit. If you must return or exchange your purchase, please contact us within 30 days of receiving your order. Your intent to return must be in writing, include a reason for return and sent to [email protected]. Please include your reason for return/exchange.

The team at eFlexFuel will then issue a return authorization number (RMA) and shipping instructions. All returns are subject to a $100 restocking fee. This restock fee is simply to help us cover freight costs (we offer free outbound shipping and will provide you with a return label), processing fees, product inspection & repackaging, and restocking time.

More About Returns

+ Warranty

eFlexFuel guarantees its products are free of manufacturing defect for 2 years of use.

If you wish to extend the limited liability warranty to 5 years, please register your product here.

More About Warranty


What's included in the eFlexPro E85 flex fuel conversion kit

Customer Comments

Note: If your vehicle is modified you can use E85 with eFlexFuel. If this is the case, please list all the main engine modifications on the checkout page. Our technical team will ensure that your setup is fit for E85.

Prop 65 Warning
Warning signNot legal for sale or use on pollution-controlled vehicles


Want $50 off your eFlex kit?

Easy! Sign up for the latest E85 and eFlexFuel News, Giveaways and Specials, and we’ll hook you up with a $50 discount code.

By providing your phone number, you agree to receive promotional and marketing messages, notifications, and customer tservice communications from eFlexFuel. Message and data rates may apply. Consent is not a condition of purchase. Message frequency varies. Text HELP for help. Text STOP to cancel. See terms.