In article Duke Ionescu writes: $I am wondering if there is any detriment to not using synthetic in this $little turbo engine. I hear synthetic is recommended for extreme $temperatures, does this apply here?
Synthetic oils do handle high temperatures better, and turbochargers tend to get pretty hot. They have fresh (i.e. hot) exhaust gases running through them, and they compress air (and if you've ever used one of those hand pumps to pump up a bicycle tire, you'll know that air heats up when you compress it).
During normal operation, the oil is circulating through the turbo, so it never stays there long enough to have a problem - and, in fact, the oil helps cool the turbo. Some turbos (and I don't know if the
1.8t is such a design) also have engine coolant running through them. But when you turn off the engine, fluids stop flowing, and that can basically cook your oil. The cure is simple - let the turbo cool off before turning off your engine. Idling or gentle driving for a little while should do the trick.
$ I currently live in NYC but am $moving to south Florida after New Year's - should I plan on using $synthetic down there because of the warmer weather?
One of the reasons I use synthetic oil here in Toronto is because of the other end of the extreme temperature range: synthetic oils flow better than conventional oils of equivalent weight when it's cold. If my car has been sitting outside on a cold winter evening, I want as much oil flowing as soon as possible.
It's obvious that synthetic oil is better than conventional oil. It's not obvious whether this actually makes a significant difference to your engine's lifetime. By changing your conventional oil more frequently than the manual says, you're also doing something that's obviously good for the car.
Me, I use synth. Started it two cars ago, and I use synth on my A4 1.8t. If I were to use conventional, I'd be nervous about the car's 16 000 km oil change interval and I'd probably change it every 8 instead - and with two oil conventional oil changes compared to one synthetic oil change, I'd probably end up paying about the same for oil changes either way, which negates the "But synthetic costs too much" argument.