Did some searching but couldn't find a conclusive answer. Does ethanol content make a difference as far as intake valve deposits go on a DI engine? Assuming both fuels are top tier.
10% ethanol vs ethanol free and intake valve deposits
- Thread starter HoosierJeeper
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Intake Valve Deposits
A series of 5,000-mile tests were run on an FFV using varied mixtures of ethanol and gasoline. The results showed that with no additive present, ethanol impacts the amount of intake valve deposits formed in the engine. At lower levels of ethanol such as E10, intake valve deposits actually increase to higher levels than in gasoline alone. However, in blends with higher levels of ethanol, the level of intake valve deposits actually decreases to the level found in gasoline, or even lower. Gasoline and E10 blends are commonly treated to reduce these deposits for improved emissions, performance and fuel economy. E85, even with its lower deposit impact, should still be treated and does not normally contain sufficient levels of deposit-control additives (Figure 1).
Since fuel does not come into contact with the valve surface that is contaminated, no cleaning effect happens. Additives, all that is moot.
As far as fuel induced deposit formation, I think there may be something to it. If fuel dilution is increased, and IF the overall volatility of the oil is affected because of it, then that can be a cause for concern. However, I don't know how ethanol vs gasoline is or the octane ratings of gas, I do know that the winter gas formulation is going to be more volatile than the summer. I'm sure there are plenty of people here that can provide valuable information regarding my speculation.
On a DI engine the gas is injected after the intake valve. This doesnt wash the valve the way PI does. On a DI engine dirty intake is caused by blowby from crank case vent. A catch can may prevent this. Doesnt matter if it has ethanol or not.
Between the PCV valve and EGR, those are the usual suspects from issues with DI. My Accord is EGR-less. I would say that most cars driven to the point of burning 
off impurities seem to usually have less issue.
off impurities seem to usually have less issue.Similar threads
