Breaking up e30 usage

[Stkid93]

When constantly running e30+ are you supposed to run a tank of 93 every once in a while to break up the e30 usage? I know running full e85 on DI clogs the hpfp, but e30 is not supposed to have that same problem (or if it does, it doesn’t clog the hpfp as quickly) so Will the 93 help clear anything out?

 

[gtx3076]

When constantly running e30+ are you supposed to run a tank of 93 every once in a while to break up the e30 usage? I know running full e85 on DI clogs the hpfp, but e30 is not supposed to have that same problem (or if it does, it doesn’t clog the hpfp as quickly) so Will the 93 help clear anything out?

This ain’t an MS3. I only run 93 on the rare occasion I’ll be too far from an E85 station maybe once or twice a year.

 

[esp_martin]

When constantly running e30+ are you supposed to run a tank of 93 every once in a while to break up the e30 usage? I know running full e85 on DI clogs the hpfp, but e30 is not supposed to have that same problem (or if it does, it doesn’t clog the hpfp as quickly) so Will the 93 help clear anything out?

how does a higher octane fuel clog anything? my understanding was it just isn't energy rich enough for the fuel pump/injectors to make up the volume difference.

 

[Ford ST]

how does a higher octane fuel clog anything? my understanding was it just isn't energy rich enough for the fuel pump/injectors to make up the volume difference.

The alcohol in ethanol is corrosive, so it can oxidize and emulsify into a by-product that isn’t combustible. Over time, this buildup can clog things up.

 

[oldedub]

how does a higher octane fuel clog anything? my understanding was it just isn't energy rich enough for the fuel pump/injectors to make up the volume difference.

It has absolutely nothing to do with the octane rating.
When I was growing up in Michigan, it was SOP to add alcohol at each fill up in the form of what was commonly referred to as "dry gas" or "gas line antifreeze". The general idea being that any water condensed in the fuel tank would be absorbed and held in solution by the alcohol and combusted per usual.

My understanding today is that the ethanol present is gasoline can hold moisture just like "dry gas", and that presence of absorbed water in some instances may not play well with the metallurgy of certain components. More ethanol could potentially carry more water. There may be metallurgy compatibility with ethanol itself in some instances, but I can't really speak to it.

E85 has only recently become available in my town, and haven't really read up on it, so I may be full of shit. That's how I currently understand it, though.

 

[Ford ST]

It has absolutely nothing to do with the octane rating.
When I was growing up in Michigan, it was SOP to add alcohol at each fill up in the form of what was commonly referred to as "dry gas" or "gas line antifreeze". The general idea being that any water condensed in the fuel tank would be absorbed and held in solution by the alcohol and combusted per usual.

My understanding today is that the ethanol present is gasoline can hold moisture just like "dry gas", and that presence of absorbed water in some instances may not play well with the metallurgy of certain components. More ethanol could potentially carry more water. There may be metallurgy compatibility with ethanol itself in some instances, but I can't really speak to it.

E85 has only recently become available in my town, and haven't really read up on it, so I may be full of shit. That's how I currently understand it, though.

I would agree with all of this.

 

[Ford ST]

I have had my car since 2017, and I have probably read about 90% of everything posted on this site. I have never seen a issue with these cars and ethanol. With that said there are additives you can use that are supposed to help prevent ethanol and gasoline from separating with some other benefits.

 

[gtx3076]

OP is coming from Mazdaspeed and Subaru platforms it sounds like. Mazdas had finicky motors whose HPFP could get so gummed up with “Black Death” residue it could inhibit the pump and cause a lean condition and vent the block.( If I remember correctly). Running 93 on occasion, or using redline fuel injector cleaner, even applying it directly into the HPFP became a common ritual for speedsters. All that nonsense plus some is why I don’t miss those cars. Ecoboosts just easier to own than the DISI motors.

Most of the speed forums was about how to keep the damn things running or all the headaches they kept running into post rebuild.

 

[esp_martin]

It has absolutely nothing to do with the octane rating.
When I was growing up in Michigan, it was SOP to add alcohol at each fill up in the form of what was commonly referred to as "dry gas" or "gas line antifreeze". The general idea being that any water condensed in the fuel tank would be absorbed and held in solution by the alcohol and combusted per usual.

My understanding today is that the ethanol present is gasoline can hold moisture just like "dry gas", and that presence of absorbed water in some instances may not play well with the metallurgy of certain components. More ethanol could potentially carry more water. There may be metallurgy compatibility with ethanol itself in some instances, but I can't really speak to it.

E85 has only recently become available in my town, and haven't really read up on it, so I may be full of shit. That's how I currently understand it, though.

i always forget about the increased possibility of water content issues with ethanol compared to 93OCT. big reason why so many people grumbled when E10 became a pretty common thing in most city limits. thanks for the heads up.

that said i know almost all Big Three vehicles made after 2010 like a little ethanol in their fuel tanks. it's not just marketing (edit: not that anyone's saying that here. i just remember growing up in Louisville how people with cars made in the 80s or 90s hated the E10 mandate when it was implemented and possibly for good reasons). our powertrains are engineered with at least some ethanol in fuel mixtures in mind. to what degree i have no idea but at least E10.

FWIW i run e30 tune in the summer and 93OCT tune in the fall, winter and early spring.

 

[akiraproject24]

I garage/store the car for like 5 or 6 months outta the year so I swap back to 93 when putting it away. Without a gauge though you may start creeping up from E30 after a few tanks depending on how dry you run it before filling up and how much math you actually feel like doing each time. I dont use enough full tanks a year to bother with resetting. If I did I probably would though.