Of all the alternative fuel vehicles, flex-fuel vehicles (FFVs) are probably the closest in general characteristics to conventional gasoline vehicles. At one point they did require special motor oil, but that requirement is no longer the standard. Late-model FFVs generally follow the same schedule as their non-FFV counterparts.
What to Be Aware Of
Because these vehicles can burn E85, they require specialized fuel system components. How come? It’s the alcohol content. E85 contains 85 percent ethanol, which is considered a caustic compound. Even in concentrations as low as 20 percent, the alcohol can deteriorate the non-synthetic, rubber parts in fuel systems. Therefore, these systems require synthetic gaskets and seals.
In addition, some metals can be damaged by high levels of alcohol, and vehicles with these systems often need to have stainless steel or another composite metal that will not be damaged by the alcohol.
Along with alcohol’s caustic nature, it also has different burn characteristics than gasoline. To compensate, the engine management systems are designed with additional specific sensors to measure the alcohol concentration and signal the on-board computer to adjust parameters such as ignition timing, fuel flow rate and air/fuel ratio.
Bottom Line
When doing the maintenance on these vehicles, any fuel system and engine management system repairs or parts replacement must be done with E85 compliant parts and procedures.
For routine maintenance on your flex-fuel vehicle, see our General Routine Maintenance for Alternative Fuel Vehicles.
Check out some other great Alternative Fuel Vehicle Maintenance articles.
The Alternative Fuel Bible: Find Answers to Your Fuel & Vehicle Questions