E10 petrol, direct injection and carbon build-up

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cws196

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Chatting with a head MB tech recently who told me they are starting to see increasing numbers of petrol direct-injection engines with carbon build-up on the injectors and unofficially MB are blaming E5 fuel. He predicts it will only get worse and advised me to start using a fuel treatment such as Forte on my C43. What are other people’s opinions on all this?
 
Carbon build up is a problem that other manufacturers have encountered on valves but I'm not aware of a link to the ethanol content of fuel. It a fundamental problem with direct injection itself because the back of the inlet valves are no longer washed by the incoming mixture as they are in port injected engines. One solution that has been implemented on some engines is to have both port and direct injection. To me adding extra complication is a poor way forward. If direct injection is fundamentally flawed then don't use it because the marginal benefits are not worth the downsides.
 
My understanding is that Mercedes direct injection engines fitted with Camtronic should in theory be less prone to inlet valves fouling, because the better-controlled valve timing will help prevent blow-back past the inlet valve. But time will tell how effective this is in the long run.

With regards fuel detergent e.g. Redex/Forte/BG44K/Millers etc, in principle they are recommended, and will help reduce carbon build-up in general, but I am not sure if they will help much specifically with preventing carbon build-up on the inlet valves of direct infection engines.

Additionally, using premium fuels e.g. Shell V-Power or BP Ultimate will unnecessiate the need for additives (because premium fuels already contain them).
 
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Chatting with a head MB tech recently who told me they are starting to see increasing numbers of petrol direct-injection engines with carbon build-up on the injectors and unofficially MB are blaming E5 fuel....

Carbon build up is a problem that other manufacturers have encountered on valves but I'm not aware of a link to the ethanol content of fuel...

Well, he said that MB are blaming it on E5 petrol, not that E5 petrol was the cause.... :D

As things stand, if anyone is concerned about high Ethanol contents in the fuel, Shell V-Power E5 seems like the safest bet, as it looks like it will continue to contain little or no Ethanol.
 

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