Flyin EVO 2ning

05/05/2026

The price difference between E85 and 93 is huge! You don’t need a larger fuel system to run E25, which is a blend of 87 octane and E85. You can just mix it using the proper ratio, but for wide-open throttle, many engine computers do not compensate for the lighter fuel with a higher amount of ethanol. If you have a newer GM vehicle, you might be in luck.

Most GM flex-fuel-ready vehicles are the ones that were factory-equipped with RPO code LMG, L20, L96, LY6, LC9, LMF, or any GM engine labeled “FFV.” These models already have the flex-fuel sensor wiring in the harness, even if the physical sensor is not installed.

GM MODELS THAT COME PRE-WIRED FOR A FLEX FUEL SENSOR Below is the consolidated list of GM platforms that—based on factory FFV engine options—are already wired for a flex fuel sensor from the factory. These vehicles either shipped with the sensor or have the connector and ECU logic ready for plug-and-play installation.

🚚 GM Trucks & SUVs (Most Common) These are the easiest because GM built millions of them with FFV capability. 2005-2020 Silverado / Sierra 1500 • Engines: 5.3L LC9, LMG, L59, L20 • All FFV variants have the wiring present. • Non-FFV 5.3 trucks often still have the harness pinned for the sensor. 2007-2020 Tahoe / Suburban / Yukon / Yukon XL • Engines: 5.3L LC9, LMG • Nearly all 5.3 trucks in this era are FFV-ready. 2007-2014 Avalanche • Same LC9/LMG FFV wiring as Silverado. 2010-2020 Express / Savana Vans • Engines: 4.8L L20, 6.0L L96 • FFV wiring present even when the sensor is not installed.

🚗 GM Cars (Factory FFV) These models shipped with flex-fuel sensors or the wiring for them: Chevrolet Impala (2006-2016) • 3.5L LZE, 3.9L LZ9, 3.6L LLT/LFX FFV variants • GM part 13507129 is listed as the OE sensor for these cars. GMPartsDirec... Chevrolet Monte Carlo (2006-2007) 3.5L / 3.9L FFV engines • Same sensor family as Impala. GMPartsDirec... Chevrolet Malibu (select years) 2.4L LE9 FFV models • Harness is pinned for the sensor. Buick LaCrosse (select years) • 3.0L / 3.6L FFV variants. 🚙 GM Crossovers Chevrolet Equinox / GMC Terrain (2010-2017) • 2.4L LE9 FFV models have wiring present.

HOW TO CONFIRM YOUR SPECIFIC GM VEHICLE IS PRE-WIRED Even within the same model year, GM sometimes included the wiring even when the vehicle wasn’t sold as FFV. To verify: 1. Check the RPO sticker Look for these FFV-capable engine codes: • L59, LMG, LC9, L20, L96, LY6, LMF, LE9 2. Look for the 3-pin flex fuel connector Usually located: • On trucks: frame rail near the fuel tank • On cars: inline with the feed line underbody 3. Check the ECM pinout If the ECM has the frequency input pin populated, the vehicle is flex-fuel ready.

Having fully automated fuel map adjustments made on the fly depending on the percentage of ethanol is why this matters for tuning. No worry if your math is off, or you put the wrong amount of E85 vs gas in.

The tuning process to turn on this feature in your GM would take less than 15 minutes, but it does require a license fee to access the ECU utilizing HP Tuners. With prices as high as they are, and with current predictions stating high prices will not come down till the fall or possibly the winter, this flex fuel installation will still pay for itself within a few months if you are driving more than 30 miles a day. Send us a DM to discuss your tuning options.

04/28/2026

Whether your build is bigger or small, we handle it all. Message us to discuss your needs. 

04/28/2026

From Porsche LS swapped street machines to land speed record setting machines. If it has an ECU we can make it fly. Click on our page and send us a message to discuss your needs.

04/28/2026

We love the unique builds, and we love tuning them. This 911 had a swapped aluminum LS with a mild cam and a factory GM ECU. It now has more power at the wheels than the factory turbo model and is lighter, more reliable, and more affordable to repair.

Message us to tune your dreams into reality.

04/10/2026

A mix of 87 octane and E85 can replace 93 octane fuel in newer vehicles or modified cars with adjustable injector flow, offering potential savings of up to $1 per gallon without upgrading the fuel system. D 85 has an octane rating of 105. It is also beneficial to burning cleaner, allowing the oil and engine to run cleaner. If you have a flex fuel car that requires 93 octane I would recommend running a 30% blend if you are trying to achieve respectable fuel mileage while having the performance of 93. 

If you see my previous post, I discuss how this specific blend equals 93 octane, here is an easy ratio that you should save into your phone.

I am currently running this blend in my daily driver, 2010 Volvo XC 60 with the turbo charged 6 cylinder. As long as I stay off of wide open throttle, even up to 60% throttle, the modern fuel system of cars newer than 2010 will keep the fuel trims in Check to compensate for the E 85 blend. 

If you want me to re-tune, your modified car’s 93 map to run this blend for wide open throttle, or to set up and tune a true flex fuel system, direct message me for a tuning appointment. Here is a simple ratio to save in your phone for reference.

04/06/2026

Want to save money on 93 octane fuel, have an adjustable fuel pressure regulator and access to E85?
If you have very little knowledge of air fuel ratios, ethanol, or do not know how to equate percentages from ethanol content and percentages of gallons, please do not try this.

E25 using 87 octane as the base is equal to 93 octane. The 25 percent ethanol raises the octane from 87 to 93. You will need to perform some basic math. Let’s go off of a 15 gallon gas tank just for example. The majority of fuel in the United States is E 10 meaning that there is already 10% ethanol in base fuel pump gas. We are wanting to bring that up to E25. Take 3 gallons of E85 and multiply .85 by 3, you should have 2.55. Now take 12 gallons of 87 octane E10. Multiply .10x12=1.2 Added to 2.55=3.75.

Now divide that 3.75 by 15, the 15 total gallons of gas (12 being E10 87 and 3 being E85). 3.75/15=0.25 AKA E25.

So you now have your cheaper E25 93 octane fuel. Now we need to run 12% more fuel to compensate for the lighter E85.

Let’s say you are running 43 psi of base fuel pressure and you want to add 12% of fuel, you will need to multiply your base pressure by 1.2544 43x1.2544=67.661. Yeah, it sounds high at first glance, but for pressure vs. flow, it’s actually pretty modest.

Why 25% pressure isn’t “crazy” for 12% flow you ask?

Flow doesn’t scale 1:1 with pressure, it scales with the square root of the pressure ratio: Also of course you may have to bring the pressure slightly up or down depending on your fuel set-up. Those with closed loop under wide open throttle will be the ones who will get the easiest end result.

So for my example of a 43 psi base, your base fuel pressure multiplied by 1.2544 gets you 67.661 (12%more flow from your previous base pressure) and you are good to go. If a little fat or a little rich, take a few or add a few psi. Cruise normal, then slowly get into it watching that air fuels are correct. 

I would highly recommend having a wide band gauge, and a ethanol tester test tube. I am posting this from my own personal experiences, try at your own risk, double check your math. No warranty your responsibility is expressed or implied.

The main important things to remember is to know exactly how many gallons you will be able to put into your gas tank, and figure out how many gallons of E85 you need and how many gallons of 87 you will need to get it to 25% Ethanol.

If you have no way of raising your fuel pressure 25.44 percent, DONT do this, make sure you have a math buddy to double check your math, or try AI. 

03/17/2026

Get them to da Choppa! **tGT

03/05/2026

03/05/2026

Interesting… I wonder If the same is true for street cars with roll cages and a parachute???🧐🧐🧐