well if it is an high performance output egine use high octane or go get a bottle of octane booster and regular gas.if low output use regular gas
not worth changing the crankshaft, better to swap the engine with new or used engine, now if it is the camshaft that is more cost effective.
A few problems you would expect with a used Volkswagen Passat are problems with the fuel system, braking system, and engine.
That depends on the condition of the engine. Generally, use the lightest grade oil that will keep the oil pressure up. Follow the manufacturers recommendations but if the oil pressure falls too much when the engine is hot, change to a higher viscosity oil. I use 5W15 in ours.
At least 91 Octane. The higher octane is to prevent engine knock- esp susceptible b/c of the turbocharged engine.
5w-30 grade sm or sl.
detonation.
A good price for a used Volkswagen Passat in excellent condition is about $15,000. Newer years' models of the Passat tend to cost around $20,000, though.
5w30
5w30
I would recommend at least Grade 8, just to make sure.
Here's what I used for my 2006 Passat: http://forums.vwvortex.com/zerothread?id=3334037
10 w 30