My A3 is a 2.0 turbo petrol and it handled fine when I went to collect the hull. The trailer was well out of balance without the engine, but it didn't affect the driveability. It was a little sluggish on the hills mind you and only managed an average of 17mpg over 200 miles
. I wasn't driving slow.
I haven't actually towed it yet fully rigged. I chickened out using it on my first launch and borrowed a friends 4x4 in case I needed to make a quick retrieval up the slip. Although it should be comfortably within the 1.8 ton towing limit, I was a bit nervous and why stress it if there's somebody else's jeep to dunk instead
I think the 2.0 diesel would be equally as ok, probably a lot more economical, but I found it had too much turbo lag for my short local driving needs.