What's the truth about ethanol and OCIs?

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346
Location
Brittany, France
I've been gathering infos here and there for a few months now especially in a few threads i made however i'm still trying to understand how E85 and E100 impacts oil. Most of the information i found is pre 2011, before the API SN spec and i think that's the reason why flexfuel cars owner's manuals say to cut OCIs in half. On top of my newbie's head, fuel dilution could be a concern since way more fuel is dumped in but on the other hand, oil stays cleaner since there's far less soot/carbon contamination. As an exemple, in my car the oil stays cleaner but mileage went from 36 mpg on regular gas and highway driving to 23 mpg on E85 for the shorter distances i currently do, it obviously has an impact on how often i should change the oil. Are OCIs different if the car is run on E85/E100 vs gas in Brazil? Brazil had ethanol decades before the SN spec. Please avoid any uneducated "ethanol is corrosive, it eats up rubber and aluminium and will require 2k oil changes" etc. I'm after facts, all kinds of UOA from everywhere around the world as well as translated studies written in portuguese, swedish etc are welcome.
 
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2,323
Location
WY
I know the change interval on cars running methanol in racing is really short. Of course they are racing engines.
 
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172
Location
Brazil
I see you are looking for this answer for some time.

To tell you the truth, you won't find it easily. Partially because there is a lot of misconceptions about using ethanol on internal combustion engines, and the fact that only a few countries like Brazil, has a true experience about using it on a regular basis. I can tell you, oil analysis is not common here (Brazil), so to find a direct comparison of UOA, will be very difficult.

The most reliable source would be the owner's manual. We can say that there are 2 "generations" of cars that run on E100 here in Brazil: Neat ethanol cars (that have been developed to only use ethanol 100% of the time - produced since the 1979 to mid 90's) and Flex fuel cars (the first one came in 2003 and are made until today). I own both, and neither have any advice or addendum saying to change the oil sooner when using E100.

My 94 Kadett has 12:1 compression vs 8,5:1 of the same engine that only runs on gasoline. The subtle difference is a dome on top of the piston. E100 needs that compression to work properly, and a few other things as well. What i am trying to say is that, if it's developed to run with that fuel, you don't have to worry about.

The increase in fuel consumption doesn't mean you are dumping a lot more in your oil, it's just the nature of the different fuel you are using. If the machine is developed for it, and need to be efficient, all of that extra fuel will be used where it needs to be: to make power.

One thing is certain about ethanol: it doesn't like to run cold. Every cold start your engine will take some time to start to burn properly, especially if you live in cold weather and is running on carb or old EFI technology. So you will have some excess of ethanol and water that could go to your oil. The good thing is, it will not mix with the oil that easily and can evaporate quickly.

If the above apply, and you are running very short trips, maybe you have to reduce your OCIs. But that would also be true with gasoline. By how much? Guess you will only find out by doing a couple of UOAs
 
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8,972
Location
Houston, TX
I ran E85 in my 2010 FX4 many, many times when towing. I also performed numerous UOAs and truth be told I could see no difference between a gasoline and an E85 UOA.

Ford stated something to the effect after running three or four tankfuls of E85 you should run at least one tank of gasoline. I tend to think that had something to do with the fuel injection system versus anything else. In the end though, I could see no difference either way.
 
Messages
34
Location
SP, Brazil
You don't have to worry about it at all, even if the car isn't E100 or flex fuel from factory, if the EFI system is well adjusted to run E100 or E85 and by that I mean running the proper air/fuel ratio for ethanol you will be just fine. That is very very common here in Brazil specially in natural aspirated cars modified to run with turbo chargers, they ALL run with E100 with no problems at all.
 

M119

Thread starter
Messages
346
Location
Brittany, France
I'm glad you gave me all the answers i wanted. I specifically thought about you Leostrop and ChristianBerg. Now i really want to share what i learnt here with everyone in europe bashing ethanol saying it wears out engine extremely fast. Leostrop, do you have good results with a non SN HDEO and ethanol? I'd like to try something like Shell Rimula or Motul Tekma next.
 
Messages
34
Location
SP, Brazil
What about corrosive wear ?
The only thing I saw all these years that was corroded a little bit faster when compared to a similar gas engine was the spark plugs. But that was in a carburated engine. 5 years ago me and a friend both installed an Iridium set of NGK spark plugs both in very similar cars. My car have a VW 2 litre engine gasoline, fuel injected(its an engine similar to the ones in US Volkswagen Fox) . My friend have the SAME CAR with the same engine but it is carburated and E100 from factory, both ran similar mileage by year and ethanol literally corroded the spark plugs in 4 years and a half, but my spark plugs running on gasoline still OK and running great. Besides that the E100 engine of my friend's car still running great, with 185,000 kilometers running on E100. For example, 80s and early 90s cars running E100 from factory, they all were carburated, their carburetors have a nickel protection to prevent corrosion. Fuel pumps are also treated against corrosion to run E100 but what I'm trying to say is that other than some parts that are in direct contact with ethanol, there are no issues with corrosion. I haven't seen all this time corrosion in cylinder heads, pistons, pistons rings, oil pan, etc. Nothing, even in converted gas to E100 engines.
 
Messages
34
Location
SP, Brazil
I'm glad you gave me all the answers i wanted. I specifically thought about you Leostrop and ChristianBerg. Now i really want to share what i learnt here with everyone in europe bashing ethanol saying it wears out engine extremely fast. Leostrop, do you have good results with a non SN HDEO and ethanol? I'd like to try something like Shell Rimula or Motul Tekma next.

You can invite all skeptical people in Europe to come to Brazil to see a BUNCH of ethanol cars, some with more than 25 years that stills running great. I'll left to LeoStrop to tell you his experience using HDEO oils in his E100 cars but it isn't something necessary to run E100. All oil bottles here comes with a little note saying 'passenger car motor oil for use with Gasoline, Ethanol or Natural Gas engines' even the cheapest 20w50 API SL Dino oil.
 
Messages
172
Location
Brazil
I'm glad you gave me all the answers i wanted. I specifically thought about you Leostrop and ChristianBerg. Now i really want to share what i learnt here with everyone in europe bashing ethanol saying it wears out engine extremely fast. Leostrop, do you have good results with a non SN HDEO and ethanol? I'd like to try something like Shell Rimula or Motul Tekma next.

To tell you the truth, i can not say if i have success with an oil or not, there is no way i can measure it. The cars run great, but being and old GM and a Honda, they could probably do it on anything. I use HDEO for a bunch of reasons, and maybe the most important is the availability. But possibly all SL oils would work just fine, that is what is on my Fit, and is what the manufacturer specified. Heck ,the Kadett survived with the recommended SF - SG!

Ethanol is corrosive, of course, that is why the right materials must be used, and avoid situations where it can sit too long in places where it shouldn't , also helps. Like super short trips or just starting the car cold for a few seconds. @TiGeo presented an article that illustrates the situation. But having 6% of fuel dilution is also very high and a bit unusual for a normal application.

It really works around here. Maybe the only hate you can find is the mpg (which compensate with the price), or someone having to start an old carbureted ethanol car in a cold morning, with no gas or WD. 😆

Hope it helps you.
 
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