E15/E85 Fuel System Compatibility Guide
Complete reference for ethanol-compatible materials, UL listings, retrofit procedures, and compliance requirements for dispensing E15 and E85 fuels.
E15 (15% Ethanol)
- - Approved for 2001+ model year vehicles
- - Requires E15-compatible equipment certification
- - Year-round sales allowed in most states
E85 (51-83% Ethanol)
- - Requires Flex-Fuel Vehicle (FFV)
- - UL 87A listed equipment mandatory
- - Higher octane (100-105), often lower price
Materials to AVOID with E15+
Buna-N
Swells & deteriorates
Brass
Dezincification
Zinc/Galvanized
Dissolves, clogs filters
Bare Carbon Steel
Accelerated corrosion
| Material | E10 | E15 | E85 | Notes |
|---|---|---|---|---|
| Viton (FKM)seal | Yes | Yes | Yes | Preferred seal material for all ethanol blends. Excellent chemical resistance. |
| PTFE (Teflon)seal | Yes | Yes | Yes | Excellent ethanol resistance. Common in valve seats and gaskets. |
| Buna-N (Nitrile)seal | Yes | No | No | NOT compatible with E15+. Will swell and deteriorate. Replace with Viton.Use: Viton, PTFE |
| Neopreneseal | Yes | No | No | Limited ethanol resistance. Not recommended for E15+.Use: Viton, PTFE |
| Standard Fuel Hosehose | Yes | No | No | Must be replaced with UL-listed ethanol-compatible hose for E15+.Use: UL 87A listed hose |
| UL 87A Listed Hosehose | Yes | Yes | Yes | Required for E15 and E85. Multi-layer construction resists ethanol permeation. |
| Stainless Steelmetal | Yes | Yes | Yes | Excellent for all ethanol blends. Preferred for piping and fittings. |
| Aluminummetal | Yes | Yes | Yes | Generally compatible but may corrode with contaminated fuel. Anodized preferred. |
| Brassmetal | Yes | No | No | Dezincification occurs with high ethanol. Avoid in E15+ systems.Use: Stainless steel, Bronze (tin-based) |
| Zinc / Galvanized Steelmetal | Yes | No | No | Ethanol dissolves zinc coating. Creates deposits that clog filters.Use: Stainless steel, Coated steel (epoxy) |
| Carbon Steel (bare)metal | Yes | No | No | Accelerated corrosion with ethanol, especially if water present.Use: Stainless steel, Internally coated piping |
| Fiberglass (FRP)plastic | Yes | Yes | Yes | Most FRP tanks are E85-compatible. Verify manufacturer certification. |
| HDPEplastic | Yes | Yes | Yes | Compatible but may have higher permeation. Check UL listing. |
| PVCplastic | No | No | No | Not compatible with any fuel. Never use for fuel systems.Use: HDPE, FRP |
Recommended Materials for E85
Seals
Viton (FKM), PTFE
Hoses
UL 87A listed
Metals
Stainless, Aluminum
Tanks/Piping
FRP, HDPE, Coated Steel
Frequently Asked Questions
What materials are compatible with E85 fuel?
E85-compatible materials include: Viton (FKM) and PTFE for seals, stainless steel and aluminum for metals, and fiberglass (FRP) or HDPE for tanks/piping. Materials to AVOID include Buna-N (nitrile) rubber, brass, zinc/galvanized steel, and bare carbon steel - all of which degrade or corrode with high ethanol content.
What is UL 87A listing and why does it matter?
UL 87A is the Underwriters Laboratories standard for dispensing equipment that handles gasoline-ethanol blends up to E85. Equipment with UL 87A listing has been tested and certified for safe operation with high ethanol fuels. Most AHJs (authorities having jurisdiction) require UL 87A listed equipment for E15+ dispensing.
Can I convert my existing dispenser to dispense E85?
Yes, most modern dispensers can be retrofitted for E85 by replacing internal seals (Buna-N to Viton), installing E85-rated meters, and using UL 87A listed hanging hardware. However, some older dispensers may require complete replacement. Always verify with the manufacturer and obtain proper permits.
Why do Buna-N seals fail with ethanol?
Buna-N (nitrile rubber) absorbs ethanol, causing it to swell, soften, and eventually deteriorate. This leads to seal failures, leaks, and contamination. Viton (FKM) rubber is the industry standard replacement as it resists ethanol absorption and maintains integrity with all ethanol blends.
What is the difference between E15 and E85?
E15 contains 15% ethanol and 85% gasoline - approved for use in 2001+ model year vehicles. E85 contains 51-83% ethanol (varies seasonally) and requires a Flex-Fuel Vehicle (FFV). E85 requires more extensive equipment compatibility but offers higher octane (100-105) and often lower price per gallon.