Should You Consider an MK7 GTI Flex Fuel Kit?

If you're looking to enhance the performance of your MK7 GTI with flex fuel, you’re probably thinking about equipping your car with an MK7 GTI Flex Fuel Kit.

This upgrade allows MK7 GTI models to run on both gas and E85, offering the freedom to choose the fuel that aligns with your driving style and goals – whether it's cost-effective daily commutes or unleashing maximum power on the track, which is what E85 is often used for. But is this kit truly a worthwhile investment?

Let's explore what’s involved with an MK7 GTI flex fuel tune and the key factors you need to consider before purchasing and installing a flex fuel kit.

What is an MK7 GTI Flex Fuel Kit?

Flex fuel kits for the MK7 GTI include both hardware and software components that give you the flexibility to run your VW on a variety of fuel blends, from regular gasoline to ethanol-blended fuels like E85.

The software component of a flex fuel kit is a tune. For instance, the IE TrueFlex MQB tune.

The hardware component of a flex fuel kit generally includes a harness and several other parts. IE flex fuel tuning solutions, for example, include these hardware components:

  • (1x) IE TrueFlex Wiring Harness
  • (1x) 2 amp Fuse
  • (1x) Ethanol Sensor
  • (2x) Ethanol Sensor Quick Connect Couplers
  • (2x) Hose Clamps

How Does E85 Benefit Performance?

There are a number of benefits of a flex fuel kit for the Golf GTI MK7, but some of the most noteworthy are as follows:

  • More Power: Adding a flex fuel kit to your VW is almost certain to free up its performance potential, resulting in both greater horsepower and more torque.
  • Cheaper: Did you know that E85 is often cheaper than regular gas? It’s true! You might even be eligible for a tax credit for flex fuel drivers.
  • Cleaner: E85 burns cleaner than regular gasoline, which equates to less carbon buildup in your engine, and it’s also better for the environment.

Are There Downsides to Adding a Flex Fuel Kit to My VW?

No. Even if you do choose to add a flex fuel kit, you don’t have to run on E85 all the time!

But, ethanol can be a little tricky sometimes, especially in extreme cold weather, or if it has not been stored properly. It’s difficult to start when it’s extremely cold out. Most cold weather states with Ethanol fuels at the pump will drop from 70-85% ethanol down to 50-60% during the winter. This is usually enough to resolve the issues and is called a cold weather blend. In extreme climates, you may find that it’s better to run 91 or 93 octane regular fuel for the coldest weeks of the year.

Other Key Considerations Before Installing a Flex Fuel Kit

  • Fuel Availability: E85 is not readily available in all areas, meaning the benefits of installing a flex fuel kit could be diminished depending on where you live and drive most often.
  • Cost of Parts & Labor: Adding a flex fuel kit isn’t necessarily an expensive modification; IE’s costs a little over $200. But complementary mods, not to mention labor, should be considered when deciding if a flex fuel kit is right for you.
  • Tuning Requirements: Using flex fuel requires a matching tune.
  • Maintenance Implications: Poorly stored Ethanol, or fuel from bad stations, may have more dirt, debris and sludge in it then you are used to. This may require filter changes or being careful to source fuel from frequently used stations.

Upgrade Your VW’s Performance with IE Fueling Solutions

Interested in unleashing the beast within your MK7 GTI? A flex fuel kit can help. Get yours now; shop all IE fueling solutions here.

Otherwise, explore other bolt-on mods you might benefit from by reading our blog post “From Novice to Expert: Building Your VW or Audi's Performance Step-by-Step”.

Flex Fuel FAQs

Is flex fuel kit worth it?

Using flex fuel results in performance gains, which is the main reason many MK7 GTI drivers choose to add a flex fuel kit to their car. It can also result in less carbon buildup. But maintenance and cost concerns, not to mention the availability of ethanol, are reasons that some choose not to add a flex fuel kit. Ultimately, for enthusiasts, adding a flex fuel kit can definitely be worth it for the performance boost alone.

Do you need a tune for flex fuel kit?

Yes. Stock VW MK7 GTI models only run on regular gasoline, not E85.

Does a flex fuel kit void the warranty?

It could. Refer to your owner’s manual and new vehicle limited warranty for more information.

Is it OK to put flex-fuel in a regular car?

No.