Should You Run E85 in Your Corvette? East Coast Supercharging Offers a Few Tips!

C8 Corvette stands to benefit from ethanol blends, but only once proper tuning is available. And it’s better for boosted applications.

If you have spent much time at the drag strip with your Chevrolet Corvette, the odds are good that you have seen or spoken to someone who was running E85 rather than traditional gasoline. Many high-powered drag cars run E85 or some other ethanol-gasoline blend and some Chevrolet products have the capability to run gasoline, E-blends or a mix of the two right from the factory. The C8 Corvette is not included in that group and owners should not attempt to run something like E85 in their LT2-powered Chevy without modifications, but for those owners planning on making more power in the future, this is all great information.

Forum member “Assassinx1” runs the Dave’s World YouTube channel and he recently stopped by CorvetteForum vend0r East Coast Supercharging to have some work done to one of his other vehicles. While there, he spoke with Doug of ECS about the advantages and disadvantages of switching from gasoline to something like E85. He shared that video in the C8 General Discussion section and while members were quick to point out that stock C8 owners should not attempt to run E85, that will be an option once LT2 tuning is unlocked.

The Pros of E85

Doug from ECS begins by calling E85 “the cheapest race gas there is”, pointing out that in many places around the United States, you can buy E85 at your local gas station just like you would 91 or 93 octane gasoline. Unfortunately, it is harder to find in some areas, but when compared to high octane racing fuel, E85 is more affordable and more accessible. He points out that with a flex-fuel sensor setup, owners can run all sorts of different ethanol blends, ranging from E15 to E90 to 93 octane gasoline, and the engine’s computer system will make the necessary adjustments to provide the best power possible.

Doug doesn’t state exactly what he drives, but he points out that from simply switching to an E85 tune, his car picked up 60 horsepower at the rear wheels. E85 has a higher octane rating than traditional gasoline, so tuners can run a more aggressive tune without concerns of running too lean. That allows the tuners to draw more power from the engine without any additional component changes, but it helps more for some vehicles than others.

Supercharged and turbocharged engines typically have the highest octane demands, so those engines generally benefit the most from switching to an E85 tune. Naturally aspirated engines can benefit from an ethanol blend tune as well, but unless they are running very high compression, they benefit less than forced induction engines. At the same time, ethanol burns cooler than gasoline, so running an E-blend also helps the engine run a touch cooler, leading some N/A road racers to run E85 as well.

The Cons of E85 in a Corvette

If you have a vehicle that has a factory flex-fuel system or your vehicle has previously been fitted to run an ethanol blend, there is only one downside to E85. Average gasoline has ideal (Stoichiometric) air-to-fuel ratio of around 13.5 to 1, but E85 is around 9.75 to 1. That means that for every one part of air, the ethanol system is using considering more fuel to reach stoitch, leading to increase fuel usage. According to Doug from ECS, E85 users will go through about 30% more fuel, so your power levels go up and your MPGs go down.

Now, if your vehicle does not have a flex-fuel system and it has not been modified to run an ethanol blend, you need to do more than just tune the engine system to run E85. Depending on the vehicle and engine, you will need new fuel system components that are designed to stand up to the corrosive nature of the ethanol. However, once you have the upgraded fuel system components, a proper engine tune will allow you to unlock extra power with E85.

Of course, since tuning has not yet been unlocked for the LT2 in the C8 Corvette, running E85 is a bad idea. It will likely cause a misfire and your car will run poorly. Once tuning has been unlocked, some simple fuel system changes and a good tune will allow C8 owners to get up past 500 horsepower without any other major changes.

Click here to head into the thread discussing E85.