Everything You Need to Safely Run Your Car on E85

Everyone is looking for the most bang for your buck (literally) when trying to make more horsepower. E85 has become a staple in everything from street cars to race cars, and is one of the biggest power-adders you can leverage within your build. Not only can E85 get you huge power gains when compared against pump gas, it’s cheaper than pump gas, and generally safer due to its higher octane and knock resistance threshold. That sounds great on paper, but as with all things, there are tradeoffs and best practices you must consider. We’ll show you the do’s and don’t’s of E85 setups so you can avoid common mistakes, mitigate the risks, and enjoy all the good stuff that ethanol has to offer. 

Do’s and Don’t’s with E85

There are plenty of pros and cons to switching your fuel system to E85. We’ll give you some highlights of what you should do when you make the transition and what to avoid to reduce unnecessary risks. 

E85 Do’s

Buy larger fuel injectors, fuel pumps, and tune your ECU before using E85

Consider a flex fuel (pump gas + E85) tune to maximize usability and daily driveability

Confirm all fuel system components are E85 compatible. 

E85 Don’t’s

Don’t run E85 without the proper parts and tune

Don’t expect the same MPG as a comparable pump gas setup 

Don’t let E85 sit for long periods of time, do not store your car with ethanol in your tank 

Common Misconceptions about E85

There are a lot of opinions about E85, and what you need or don’t need. We’re going to run through some of the biggest misconceptions and explain the difference so you can make changes to your car with confidence. 

Although ethanol can deliver a serious boost in performance, it isn’t magic. There’s work you need to do to ensure you’re getting the most out of it, and most importantly, doing it safely. For example, your setup will need to keep up with the substantially increased volume demands. Fuel injectors and upgraded pumps will handle that, and pressure regulators will support proper balance. Monitoring your air-fuel ratio and ethanol purity (if not on a flex fuel tune) will support optimal conditions for a better driving experience. 

Will E85 destroy your engine? No. Most modern cars and aftermarket parts are ethanol-compatible, making the switch to a flex fuel system easier than it used to be. There are other concerns to consider like moisture absorption. Ethanol absorbs water, which can lead to corrosion and fuel contamination if the car sits for weeks or months. Poor maintenance and fuel setups are what lead to problems with E85. You can make E85 work for you with the right parts. Let’s take a look at what you’ll need to upgrade your fuel system. 

How to Upgrade Your Fuel System for E85

Fuel Pumps

AEM E85-Compatabile High Flow In Tank Fuel Pump

Designed for ethanol and menthol fuels, this fuel pump is ready for increased demand that comes with an E85 conversion. Engineered to support naturally aspirated and forced induction builds, this fuel pump makes it possible to accommodate a wide range of applications. 

Walbro 450LPH E85 In Tank Fuel Pump

Need even more flow? This Walbro fuel pump is engineered to support 750+ horsepower. If your build will land somewhere within that range, especially on E85, this is a great option and will prevent the need for a secondary pump. 

Injectors

Injector Dynamics ID1300x

ID is well known for their quality injectors. The 1300x offers stainless internals for excellent durability against the corrosive nature of ethanol. Its compact body allows fitment in 200+ applications, making it a versatile injector for a huge range of builds and performance needs. 

Injector Dynamics ID 1750x

The ID1750x is a great upgrade over the 1300x if your build needs a substantial amount of fuel flow, without sacrificing tunability and driveability. These are the very same injectors we use in our shop Evo X! 

Fuel Rail

Radium Engineering Fuel Rail 

Designed for E85 fuel, this rail distributes fuel evenly to all your injectors, keeping fuel pressure stable, and reducing the risk of oscillations when injectors open and close as you drive. This becomes increasingly important as you install bigger injectors, and substantially increase fuel flow. 

Fuel Pressure Regulator Kit

AMS AFPR Install Kit

The AMS EVO X Fuel Pressure Regulator Kit is designed for anyone running an upgraded fuel pump and or fuel injectors. Whether you are running too rich and need to back off the fuel pressure or if you are running too lean on your current injectors and need to raise base fuel pressure, this is the system for you! A vibration resistant, liquid filled fuel pressure gauge is included allowing you to monitor your fuel pressure. Requires no cutting or modifications to your vehicle for easy installation and/or removal.

Fuel Filter Kit

MAPerformance Evo X Inline Fuel Filter Kit

The Mitsubishi Evo X Inline Fuel Filter Kit By MAPerformance (also fits Ralliart). The MAP inline fuel filter was developed as a solution to protect your fuel injectors from debris and potentially even save your engine from a clogged fuel injector, which can be a common fear for any E85 setup. 

Located between the hard factory feed line and the fuel rail installation couldn’t be simpler with the push-on EFI adapter fittings. The compact billet fuel filter features a 40 micron stainless steel element that is compatible with both pump gas and E85, and flows enough to support nearly 500lph. It is a must for anyone that has upgraded the fuel pump to a non-drop in unit, as the removal of the stock pump housing will get rid of the factory fuel filter.

Shop Fuel System Parts at MAPerformance

Find the parts you need to effectively run E85 in your vehicle. Check out our inventory of parts to learn what fits your vehicle. Contact our team to answer any questions you have about our products. Visit our blog for more information about mods, fitment guides, and other helpful articles.