E85?

[tyler.bary]

What all do i need to do to my car in order to run E85 in 1.8t mk1 quattro

[carmudgeon]

Typically injectors, fuel pump, and a reprogrammed ECU. E85 has less energy per gallon that gasoline so the engine needs to pump more. Your fuel economy will also go down.

[tyler.bary]

I get that. But will factory fuel lines be sufficient?

[hunTTsvegas]

What all do i need to do to my car in order to run E85 in 1.8t mk1 quattro

Factory fuel lines will be sufficient. It's also nice to know whether the car is Narrowband or Wideband. If narrowband, you'll need to convert to wideband (harness, wideband O2 and wideband ECU with Immo Defeat) to maximize an e85 tune.