E85 Question

Neutron · December 28, 2007

I just purchased a 2007 NNBS Silverado with the 5.3L with AFM. It's not the RPO code that is for flex fuel, but was wondering if this engine could burn E85 with no problem?

tflessner · December 28, 2007

Without the flex-fuel option, and the the numerous equipment additions (different injectors, fuel line sensor, etc.) your truck can handle burning approx. 20% ethanol. A majority of the gas sold out there right now is 10% ethanol (depending upon which part of the country you live). So, you could put approx. 4 gallons of E-85 maximum per tank full, the rest being regular gas, and not have any problems. I've done this alot for the past couple of years in mine. Just don't fill the tank full of E-85. It would probably run okay, but there are too many potential issues that could arise?

Below is information on the differences in E-85 vehicles and non-E-85 vehicles:

E-85 ethanol is used in engines modified to accept higher concentrations of ethanol. Such flexible-fuel engines are designed to run on any mixture of gasoline or ethanol with up to 85% ethanol by volume. The primary differences from non-FFVs is the elimination of bare magnesium, aluminum, and rubber parts in the fuel system, the use of fuel pumps capable of operating with electrically conductive (ethanol) instead of non-conducting dielectric (gasoline) fuel, specially-coated wear-resistant engine parts, fuel injection control systems having a wider range of pulse widths (for injecting approximately 40% more fuel), the selection of stainless steel fuel lines (sometimes lined with plastic), the selection of stainless steel fuel tanks in place of terne fuel tanks, and, in some cases, the use of acid-neutralizing motor oil. For vehicles with fuel-tank mounted fuel pumps, additional differences to prevent arcing, as well as flame arrestors positioned in the tank's fill pipe, are also sometimes used.

E-85 does not have the same energy density as gasoline. This could cause performance issues with the vehicle (hesitation, hard starting, etc. especially if you live in a cold climate). When ambient temperatures are cold, your car may have a hard time starting, because ethanol evaporates and atomizes very differently than gas, so it is much harder to ignite when cold.

Hope this helps.