so im looking at buying a 01 a6 ive found two one has the twin turbo 2.7 the other the 4.2 what are the pros and cons to these cars. what do i need to look for as far as known issues. what kind of fuel mileage can i expect from the two and what should i look to spend
thanks

 

First off, starting doing searches for both engines in this forum. You'll find tons of information about potential issues and modding.

In summary, the 4.2 engine is pretty bulletproof and puts out plenty of power. There are few mods. The weak point is the tranny and it can cost $3-4k to fix or replace. Many like the wider width and body style of the 4.2 package.

The 2.7T can be immensely modded, but turbos eventually fail ($3-4k), take more care than the 4.2, and the tranny is the weak point whether MT6 or tip.

My A6 is close to 195k, chipped, and still running the original turbos (albeit slight oil leak in one), suspension, etc. Very few problems but it has mostly highway mileage, I generally baby it, and it gets all preventive maintenance plus.