GM Service Manual Online
For 1990-2009 cars only

Use of E85 Fuels in Vehicles Not Certified by GM as being FlexFuel Compatible/Aftermarket Conversion of Vehicles to Operate on E85 Fuels

Subject:Use of E85 Fuels in Vehicles Not Certified by GM as being FlexFuel Compatible / Aftermarket Conversion of Vehicles to Operate on E85 Fuels

Models:2008 and Prior GM Passenger Cars and Trucks NOT FlexFuel (E85) Compatible (including Saturn)
2008 and Prior HUMMER H2, H3
2005-2008 Saab 9-7X



This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 06-06-04-035 (Section 06 -- Engine/Propulsion System).


Aftermarket Conversions of Vehicles to Use E85 Fuels

General Motors has become aware of several companies that claim to be able to convert vehicles equipped with gasoline engines to be compatible with E85 Fuels.

    • Vehicles certified by GM as being FlexFuel (E85) compatible contain numerous calibration and component differences that are not conducive to an aftermarket retrofit.
    • General Motors DOES NOT support or endorse conversions that may alter the emissions and related emissions components of its vehicles.
    • Repairs that may result from changes to GM built components, and repairs that result from the use of improper fuel, such as the use of gasoline containing more than 10% Ethanol in a non-FlexFuel certified vehicle, are not covered under the terms of the New Vehicle Warranty.

E85 Compatible Vehicles

The only E85 compatible vehicles produced by General Motors are:

    • 2000-2002 S-Series pickups with 2.2L (VIN 5- RPO L43)
    • 2002-2005 full-size pickups and utilities with 5.3L (VIN Z -- L59)
    • 2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe with 5.3L (VIN Z -- RPO L59)
    • 2006 Chevrolet Impala, Monte Carlo with 3.5L (VIN K -- RPO LZE)
    • 2006 GMC Sierra, Yukon, Yukon XL with 5.3L (VIN Z -- RPO L59)
    • 2007 Chevrolet Express with 5.3L (VIN Z -- RPO L59)
    • 2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe with 5.3L (VINs 0, 3 -- RPOs LMG, LC9)
    • 2007 GMC Savana with 5.3L (VIN Z -- RPO L59)
    • 2007 GMC Sierra, Yukon, Yukon XL with 5.3L (VINs 0, 3 -- RPOs LMG, LC9)
    • 2007 Chevrolet Impala, Monte Carlo with 3.5L (VIN K -- RPO LZE)
    • 2007 Saturn Relay, Buick Terraza, Chevrolet Uplander, Pontiac Montana SV6 (Canada Only) with 3.9L (VIN W -- RPO LGD)
    • 2008 Chevrolet Impala with 3.5L (VIN K -- RPO LZE) and 3.9L (VIN 1- RPO LZG)
    • 2008 Pontiac Montana SV6, Chevrolet Uplander 3.9L (VIN W -- RPO LGD)
    • 2008 Chevrolet Express, GMC Savana with 5.3L (VIN 4 -- RPO LMF)
    • 2008 Chevrolet Avalanche, Suburban, Silverado, GMC Yukon, Sierra with 5.3L (VIN 3 -- RPO LC9)
    • 2008 Chevrolet Avalanche, Suburban, Silverado, Tahoe, GMC Yukon, Yukon XL, Sierra with 5.3L (VIN 0 -- RPO LMG)