Originally Posted by metroplex
I just poured in 1 qt of MMO in a Chevy 2.0L GTDI (LTG) that has 93k miles. When I started maintaining the engine, it had 68k miles. The original/current owner said that the local Cadillac dealership had changed the oil since the car/engine was brand new in 2015. The Caddy dealer swore that semi-synthetic was all that was needed. Once the owner used up the free dealer oil changes, they had it changed at Belle Tire with Mobil 1 synthetic.
Opening the filler cap, I can see a thin layer of sludge around the fill port. The dipstick also had signs of sludge, and I had to clean off the sludge using brake cleaner. I've done 3 oil changes on it already, each time using Amsoil Signature Series 5W-30. With fresh oil, the oil on the dipstick was clear amber. Just driving it a day after an oil change, the dipstick oil becomes pitch black. The engine uses up about 3-4 quarts every 7500 miles. I add about 2 quarts by 5000 miles.
BTW - E10 or E20 is often painted as an evil fuel, but for those with GTDI engines (like EcoBoost), running E30-E47 allows for running a lot more timing and boost as the alcohol allows for evaporative charge cooling which raises the effective octane well above pump gas ratings. If you are running a tuned EcoBoost or tuned GTDI engine and sticking with 93 octane, you are leaving a lot on the table. The Bosch DI systems (HPFP and injectors) are generally designed to run up to E100/14% methanol, and most of the Fords share the same fuel tanks as their flex fuel counterparts. FWIW my dad still uses the regular E10 pump gas for his 1980s Craftsman lawnmower without any problems.
Anybody around here that uses e10 in their outdoor power equipment regrets it after one or 2 seasons. I have pictures of the inside of my father in law's lawnmower to prove it plus tests have been done that showed the same result. Even a couple different fuel stabilizers tested didn't prevent e10 from going bad while sitting in the test I saw recently. I'd like to see more fuel stabilizers tested though to see of them have any effect.
...Which reminds me I need to go help my coworker drain the fuel out of his snowblower and see if we can get it to run again. The carb is probably destroyed inside already, but fingers crossed.