There has been a lot of talk lately (and we’ve received a few emails) about enthusiasts using E85 fuel as their favorite-fill in everything from daily drivers to full-on race cars. We’ve been told for years about the extra cooling capabilities of E85, and how in boosted applications, that cooling can mean a few more degrees of timing.

We’ve always felt that opting for the lower-cost fuel with higher octane, simply wasn’t worth the effort in naturally-aspirated engines, due to the reduced fuel mileage. The fact that people were talking about the benefits of E85 in naturally-aspirated engines let us know that there were a few things we hadn’t considered with the new LT-based engines and their higher compression. There are also a few other things to know when considering E85.

The LT4 and LT5 engines are both supercharged and available as crate engines from Chevrolet Performance. The boosted engines make them prime candidates for E85, especially in modified configurations.

We recently received an email from Jason Dwyer, asking us to look a little deeper into the viability of using E85 fuels in cars other than sticker-riddled track stars. We went to our good friend and super-tuner, Mike Norris of Mike Norris Motorsports in Plainfield, Indiana and asked Mike what his experience has been using E85 fuel. As mentioned, we’ve always known about E85’s benefits for boosted applications, but we asked Mike what his dyno has shown in switching, even a naturally-aspirated, LT1-equipped vehicle, over to E85.

“The C7 (and any of the LT-based vehicles, truck and Camaro) do benefit performance-wise from E85,” he said. “We have added the flex fuel option to several of them. The fuel system in these cars is flex-fuel compatible, and after adding the necessary sensor, the capability can be turned on in the ECM.”

So, it can be done, but what kind of power increases can it bring with it? Is it worth the additional cost and effort over simply tuning an engine for optimum performance? Mike goes on to explain.

“There is more to gain with a stock, naturally-aspirated car by adding and tuning for E85 fuel than just tuning a stock, naturally-aspirated car on pump gas,” he said. “On a naturally-aspirated setup, we have seen a 20-25 horsepower gain with E85. This is mainly due to E85 working with the LT1’s high compression and cylinder head design.”

Okay, so we’re seeing the benefit here. But, like we said, we always thought that E85 REALLY shines when coupled with a supercharger or a turbocharger(s). So, if a little is good, then a little more must be really good, right Mike?

“Forced induction does benefit quite a bit for sure,” Mike confirms. But, when building a big horsepower setup, the limiting factor becomes the fuel system (low and high pressure) and the injectors.” We’ve also understood the Direct-Injection’s fuel supply to be a limiting factor, especially when starting out with the naturally-aspirated LT1 engine. The LT4, and now LT5 OEM-supercharged engines have a more robust fueling system to better accommodate the already supercharged powerhouse.

Thankfully, there are companies, such as Lingenfelter Performance Engineering, that supply aftermarket injectors, fuel pumps and camshafts to further support the larger diets of these higher-performing LT engines. Their kit for Gen-V GM V8s provides a high pressure fuel supply system that is able to support over 1200 lbs-ft of torque and 1435 horsepower at 6800 rpm.

Going “full boost” can bring great increases in performance. For truly radical engine designs, a combination of E85 and methanol injection may be necessary to keep detonation at bay. At this point, fuel mileage is as much a concern as tire tread wear.

It seems that E85 does have benefits for engines ranging from mild-to-wild, and although it’ll take a little more fuel to get from Point-A to Point-B, the typically lower cost of E85 will only take a bit of the sting out of the lower fuel mileage. The referenced Edmund’s test was done with a 2007 Chevy Tahoe with the 5.3L V8, an engine with a lower compression ratio than the current LT-based Gen V engines produced by General Motors. As such, a higher compression ratio may sway the mileage results a little more into the flex-fuel’s favor. Either way, it’s becoming more clear that E85 does have performance benefits, whether in boosted applications or naturally-aspirated. Which is good news for the power-hungry, like us.