DRIVEN® Defender Fuel System Additives
PROTECTING YOUR ENGINE AND FUEL SYSTEM FROM MODERN ETHANOL FUELS
Everyone with a classic car understands the need for high zinc oils, but what about fuels? With the advent of modern E10 fuels and E15 fuels just around the corner, older vehicles made before 2007 have fuel systems not rated for use with E15 (15% ethanol) fuels.Vehicles manufactured in or after 2006 should be compatible with E10 fuels according to numerous sources, but what makes these fuel systems compatible with E10? Modern fuel systems have PTFE lined fuel hoses capable of resisting degradation caused by ethanol fuels, but older vehicles do not. So if your car is older than 2006, you may need to take additional steps to protect your engine and fuel system from the effects of ethanol fuels. Using quality fuel Top Tier or ethanol free premium fuels and selective use of fuel additives along with upgrading to fuel system and engine components that are compatible with modern ethanol blended fuels are steps that should be taken to prevent costly failures.
WHAT IS E15?
With the introduction of E15 fuels containing up to 15% ethanol, owners of vehicles never designed for ethanol blend fuels must be ever aware of damage that can occur by not choosing the correct fuel for their classic or performance engine.
Thanks in part to lobbying groups like the National Marine Manufacturers Association, steps are being taken to protect consumers by limit the expansion of E15 sales which will eventually lead to what is coined as “misfueling” that will damage engines not compatible with these fuels. Like with modern oils, it is up to the consumer to make informed decisions as to what fuel is correct for their vehicle and not rely on fuel suppliers to warn consumers as to possible engine damage if the wrong fuel is used.
ETHANOL IS HYGROSCOPIC, MEANING IT ABSORBS WATER.
We all know what water in the fuel system is not good and can lead to damage to paper filters, water contamination, and fuel phase separation. Ethanol is also very corrosive and will promote rusting where air meets metal once exposed to ethanol fuels. Ethanol is a solvent and will cause deterioration of rubber, plastics and fiberglass that are not rated for use with ethanol fuels. Lastly, ethanol enriched fuels have much shorter shelf lives than non-ethanol fuels. More on ethanol-enriched fuels later.
TOP TIER™ FUELS
Regardless of choice of E10 or ethanol-free fuels, choosing a Top Tier™ detergent gasoline is very important. This standard, developed in 2004, ensures the fuel you receive from brand to brand and station to station meets the stringent requirements to qualify as a Top Tier fuel. Lower detergent and additive levels found in non-Top Tier™ fuels can have adverse affects on injector, valve, and chamber deposits that can cause drivability issues leading to engine damage and costly repairs.
Next time you go to put gas and see the station is accepting a fuel delivery, just keep driving by. It is a good practice not to pump when stations are receiving a fuel delivery, as contaminants can be stirred up and even though the fuel is filtered at the pump, why risk getting contaminated fuel? Avoid gas stations with slow filling fuel pumps as this can be a sign there are microorganisms living in the fuel storage tanks that thrive when ethanol and water are present. These bacteria, known as acetobacter, generate acetic acid, which is very corrosive and can cause damage to metal parts in your fuel system. These colonies can form in your fuel tank too, so untreated fuels should be used up within a few weeks to prevent damage.
Although uncommon, some gas stations offer ethanol-free fuels such as REC90 and are often sold near marinas or where there are watersports. Engines operated near or on the water cannot use ethanol enriched fuels. Areas where it is not practical to blend ethanol into unleaded fuels will often have ethanol free fuels available. There are websites and apps for your phone that will help you find ethanol-free fuel suppliers - pure-gas.org is one of them. For lack of ethanol-free or race fuels, some hot rodders have taken to using aviation fuels, known more commonly as AV gas – please don’t. These fuels have a lower density than automotive fuels and will make your car run leaner. Additives in 100LL AV gas will also cause damage to O2 sensors and catalytic converters, so these fuels might cause more harm than good.
Once you have chosen the right fuel another consideration are fuel system treatments, cleaners, and additives. Normally we are not for additives, but in this case, additional steps are required to ensure that older fuel systems are protected and that newer fuel systems are kept at peak performance. Even modern fuel systems can suffer from poor fuel quality and aging components. Regular use of Top Tier™ fuels extended component life and cleanliness, but additional steps can be taken to further improve the situation. Fuel systems not compatible with ethanol enriched fuels must ideally use an ethanol fuel treatment like Driven Carb Defender or Injector Defender with every fill-up. Modern fuel systems should always use Top Tier fuels and use a fuel system cleaner like Driven Injector Defender, LM Jectron, Redline SI-1, or Chevron Techron every 3,000 miles. If the ethanol fuel is going to be sitting any longer than a month, a storage additive like Driven’s Storage Defender™ or Sta-Bil 360 Marine Fuel Treatement & Additive needs to be added to your tank.
GET TO KNOW YOUR FUEL- WHAT IS OCTANE?
In most places, premium fuels are minimum 91 octane (AKI or R+M/2 measurement method) and some locations in the United States and Canada have access to 92, 93, or even 94 octane pump premium fuels. Most race tracks have 100 octane unleaded and even higher octane leaded fuels. AKI ratings are on average 4-6 points lower than RON or MON measurement method used worldwide.
First and foremost, never use leaded fuel in a fuel injected engine with O˜ sensors. Lead will foul O˜ sensors in as little as one tank of fuel and can lead to engine damage. Leaded fuel also contaminates the engine oil, increasing wear, so stay away from leaded fuel unless required by the engine. Older engines without hardened valve seats requiring leaded fuels (pre 1970s) can use lead substitute additives to prevent seat damage. Redline’s Lead Substitute™ uses sodium as the dissimilar metal to protect unhardened valve seats.
Most modern engines with knock-sensing are designed to take advantage of modern, higher octane fuels, increasing performance and efficiency by allowing for advanced timing to make the most of the higher octane fuel, but what is octane? The octane rating is basically a number that relates to the fuels resistance to combustion or to fight pre-ignition and detonation. In a perfect world, to maximize performance, you want to use the lowest octane required to prevent pre-ignition and detonation. Likewise, a high-performance engine or one upgraded with higher compression pistons requires premium high-octane fuel to prevent knock. The side effect is the engine makes more power. So, unless you engine requires or has modern engine management to take advantage of higher octane fuel, use of higher octane fuels is a waste of money. It’s best to refer to your engine builder’s recommendations or if your car is stock, the octane requirements stated by the manufacturer, to ensure you use the right fuel.
If you need higher octane fuel but it is not available to you, beware of octane boosters claiming boosting levels by X points – for example, a 5 point increase would actually increase 91 octane to 91.5 octane unless the manufacturer provides a table to calculate actual octane, as is commonly done with race gas concentrates like that sold by Torco Race Fuels™ or additives like Driven’s Injector Defender™ with Octane Booster.
Lastly, when it comes to older vehicles and fuel systems not designed for E10 ethanol fuels, use of additives to prevent damage is a must. For cars driven regularly, as defined by a tank of fuel used in 30 days or less, adding Driven’s Carb or Injector Defender™ will protect against damage caused by ethanol enriched fuels, and is based on the additives used in South America where E85 and E100 fuels are the norm. For vehicles that are going to be stored, use of a product such as Driven’s Storage Defender™ provides added fuel system corrosion protection and should be added to a full tank of fuel to help minimize the accumulation of moisture in the fuel tank and corrosion. Be sure to run the car after adding these additives to ensure the entire fuel system is protected.
WHY IS ETHANOL USED IN MODERN FUELS?
Corn ethanol is used as an oxygenate and octane booster in the US to conform
to ASTM D5798 ethanol fuel standards.
Looking beyond E10 or E15, testing has indicated that ethanol blended fuels,
specifically E20, has shown a reduction of CO and HC emissions, even though a
reduction of overall fuel economy of 6.5% was observed over non-ethanol blended
It was further documented that even though gasoline has a higher specific heat
energy, ethanol’s higher resistance to detonation does allow engines to run with
higher spark advance which increases thermal efficiency and output, suggesting
that older vehicles without modern ignition management and knock sensing may
need adjustment to take advantage of ethanol blended fuels.
Why is ethanol a bad thing? Aside from the argument that ethanol fuel production from typical sources such as corn is at best carbon neutral or a government subsidized industry, there are actual problems that can result from use of ethanol fuels both short and long term. Ethanol increases the water solubility of fuels, which can lead to corrosion of internal engine components. This oxidation occurs through the formation of aggressive chemicals like aldehydes and acids. As ethanol content increases, the corrosive properties of these fuels increases, having negative effects on steel, copper, aluminum, and brass, all materials common to older fuel systems.
Why is ethanol a bad thing? Aside from the argument that ethanol fuel
production from typical sources such as corn is at best carbon neutral or a
government subsidized industry, there are actual problems that can result from
use of ethanol fuels both short and long term. Ethanol increases the water
solubility of fuels, which can lead to corrosion of internal engine components.
This oxidation occurs through the formation of aggressive chemicals like
aldehydes and acids. As ethanol content increases, the corrosive properties of
these fuels increases, having negative effects on steel, copper, aluminum, and
brass, all materials common to older fuel systems.
Although it has been sufficiently documented that modern vehicles can accept modern ethanol blend fuels with minimal negative issues when doped with corrosion inhibitors, it has been well known that older vehicles are susceptible to damage from these fuels. As early as in 1983, GM published a paper in the Society of Automotive Engineers (SAE) titled “Corrosion of Metals and the Effectiveness of Inhibitors in Ethanol Fuels.” The primary takeaways were that chloride ions were the most aggressive source of contamination in ethanol blended fuels and when combined with acetic acid and ethyl acetate, corrosion was significant. Water content in blended ethanol fuels is the largest concern when evaluating the negative effects of ethanol to fuel system and engine components because water is the carrier for the corrosive chlorides, sales, and other ions that lead to corrosion. When choosing an ethanol blended fuel, using a Top Tier fuel supplier will ensure fuel dispensed meets or exceeds ASTM standards, including limits for moisture content.
On a positive note, they did document that available inhibitors could be added to reduce or eliminate corrosion of components in fuel systems and engines susceptible to ethanol blend fuels. Specifically, GM found corrosion of the carburetor, fuel pump, fuel line, fuel filter, and fuel tank becoming critical for example when small orifices in carburetors get blocked that can cause rough running or lean engine operation result-ing in engine failure. Even in 1983, there were inhibitors available that could provide corrosion protection in the fuel system as well as in storage and transport of ethanol blended fuels, many developed for the Brazilian market where E100 fuels were sold.
Doping with corrosion inhibitors (CI) can also lead to fuel filter, catalyst,
and injector plugging as well as intake valve deposits or fuel pump failure, so
excessive corrosion prevention can have unintended side effects.
Although there is no recommended specification in the ASTM D4806 for CI content,
choosing a Top Tier fuel mitigates these problems with increased detergency to
prevent these deposits and carbon buildup is recommended.
Where Top Tier or ethanol-free fuels are not available, products like
Driven’s Carb Defender can be added to any fuel to overcome the negative
effects of ethanol blended fuels without any negative side effects.
Outside of corrosion issues, the material compatibility of plastics and rubbers with ethanol blended fuels is another area of concern. Specifically, dry-out sample testing of Polychloroprene rubber hoses common in older fuel systems immersed in E10 found a 70% reduction in strength versus 10% in gasoline. In layman’s terms, cars driven infrequently where lines might drain back to the tank are susceptible to failure with ethanol blended fuels. Replacing these fuel hoses with modern, fuel injection hoses that are flex fuel compatible are recommended for all vehicles that will be exposed to an ethanol blended fuel.
Lastly, ethanol blended fuels also have reduced lubricity over non-ethanol fuels, directly effecting fuel system and engine component life for both vintage and modern engines, especially those with gasoline direct injection (GDI) or gasoline compression ignition (GCI). Elimination of sulfur from domestic fuels for emissions reasons has had an adverse, negative effect on the lubricity of fuels, increasing wear to high pressure injection pumps. Specifically, sulfur’s interaction with metal surfaces to reduce friction on metal sliding surfaces lowers abrasive wear, requiring the addition of lubrication enhancers (LE) to overcome poor lubricity of ethanol blended fuels. Driven’s Injector Defender can be used to provide added lubricity while providing protection from corrosion caused by ethanol. Even with proper dosing, acid based LE outperforms ester based LE, but with sufficient dosing, either LE additive can provide protection to all fuel system and engine components. Without knowing which LE is used and in what concentration, testing carried out by Total ACS found that premium fuels resulted in lower wear, so again, use of a Top Tier fuel in a premium grade where non-ethanol fuels are not available is highly recommended. 
WHAT STEPS CAN BE TAKEN TO PROTECT YOUR FUEL SYSTEM AND ENGINE FROM MODERN
FUELS WITH ETHANOL?
- Update fuel lines and filters to mutli-fuel compatible type. Lines and filters rated for E85 fuels will perform very well and provide excellent life with E10 fuels.
- Replace seals and gaskets with modern materials that are compatible with ethanol fuels.
- Add a water separator to the fuel system.
- Have older fuel tanks professionally cleaned and sealed to prevent corrosion.
- Replace mechanical fuel pumps with modern electric fuel pumps compatible with ethanol fuels.
- Use ethanol-free fuels.
- Always use premium high octane fuels if your vehicle can benefit from them.
- Use ethanol fuel additives to protect older fuel systems or those vehicles in storage with every fill up.
- For cars made after 2000 and if using Top Tier fuels at every fill up, add a concentrated fuel system cleaner like Driven Injector Defender at every oil change or every 3,000 miles.
- For cars made before 2000, especially older cars with carburetors or fuel system components not compatible with ethanol fuels, regular use of Driven Carb Defender or Injector Defender is recommend at bare minimum every other fill up if access to ethanol free fuels is not available.