up-n-coming

Your the one that mentioned using high quality gas is the best one can do. Cars that use regular get the same build up as cars that use premium so fuel quality isn't relevant. Fuel never touches the tops of the valves where build up occurs. Premium keeps your injectors cleaner and increases the detonation point in a DI engine, that's about it. In theory Premium is definitely better than regular in a Port injected engine at keeping valves cleaner. But build up isn't an issue even with regular.

The reason carbon builds up is that intake valves open a fraction of a second before the exhaust valves fully close to aid in savaging the cylinder fully. In that fraction of a second some spent hydrocarbons are attracted and stick to the cold tops of the intake valves. No fuel washing over the tops means excessive build up over time.

JUST TO BE CLEAR, USING A PREMIUM TIER1 HIGH DETERGENT FUEL WON'T HELP MINIMIZE CARBON BUILD UP ON DI ENGINES. FUEL NEVER TOUCHES THE VALVE TOPS. ONLY AIR DOES.

yvantheterrible

Shell does clearly market their Nitro gasoline versus "inferior quality gasoline". So quality is certainly important or an issue. Quality may be defined differently whether it means with or without detergent, it is up to interpretation I guess.

https://www.drivingthenation.com/new...ng-the-nation/

the following youtube video is also very helpful :

Published on Jun 10, 2015
Shell has released its latest fuel, V-Power Nitro+, which is designed to minimize negative effects from gunk (carbon deposits), corrosion, and wear. They’ve tested their own fuel versus competitive premium gasolines, and have strong claims against the competition. Shell V-Power Nitro+ eliminates on average 60% of carbon deposits on intake valves with port injected vehicles within the first tank. It offers unbeatable protection against gunk and corrosion, and offers superior protection against wear.

up-n-coming

Well that pretty pretty much backs up my statement that premium (high detergent) fuel benefits port injection. Not so much for DI engines.

edle

LOL - I didn't mean to open up a can of worms, I just wanted to know if there was something I can do which there is in the forms of those dealership charged cleaning which I can do every 30K-40K miles.

SCarGuy

Oil spec and change interval will yield the biggest difference on the carbon build up on the DI engines

Versprechen

Every 5000 miles is the key IMO.

lowjdml

Can someone clarify how this helps? Oil never touches the intake valves where the air is entering the engine, so how does it remove carbon buildup on the valve?

up-n-coming

LOL, I saw this thread veering off the road and tried to get it back on track. Now it went off the rails completely again.

Versprechen

Because modern engines burn oil as a trade off for better gas mileage, which can cause issue with the piston rings, so changing it a little more often can help delay the build up by making oil level is almost always optimal.

VM

Where does this idea that modern engines are designed to burn oil come from??

I know some earlier generations of the EA888 have had issues with burning oil, but I think those were defects, not some brilliant engineering. Other than the one fellow whose head was replaced, has anyone on this forum reported oil burn issues? My car (which is reminding me every day that it needs an oil change in 18 days!) seemed to report basically full last time I checked the oil level display...