I am looking at buying a 2011 BMW 335 or a 2013
Audi A4 and I was wondering which one would be
better? By better I mean price to quality ratio and
reliability and the ability to tune and customize the
car. Also how customizable is the Audi A4 for more
I do not agree with the answer above. Both of those cars have a ton of untapped potential...especially if the 335 is an N54 variant (actually bi turbo as opposed to the twin scroll N55 version). The B8.5 A4 which started in 2013 also has a ton of potential, especialyl if it has the ZF8 8 speed auto trans (because the zf8 cars are flex fuel capable from the factory and have a 5th injector on the Intake manifold to support the extra fuel required to maintain correct stoichiometry of e85). The 2.0T in the A4 comes stock at 211 crank hp and 258 ft/lbs. The car was slightly underrated from the factory but the drivetrain is capable of much more. With a simple OTC tune from the likes of APR or Unitronic the IHI turbo 2.0T is capable of squeezing out about 80 more hp and 150 ft/lbs of torque on E85). For even more power, there are a plethora of companies that offer K04 turbo kits. The K04 turbo is the same size turbocharger from the S3 of the same generation. Companies like CTS and APR have created a version of it that bolts right up to the longitudinal motor in the B8 A4/ Allroad/ Q5/ A5. My 2013 Allroad (same motor as the 2013 A4) made 322 hp and 418 ft/lbs at the WHEELS) with the CTS turbo K04 kit. That equates to about 380 hp and closing in on 500 ft/lbs. It ran a 12.3 1/4 mile at 112mph. For comparison sake, a stock 2013 RS5 runs a 12.8. All of this extra power can actually be attained reliably too....135k miles on my allroad and it has been tuned since 40k. Zero issues. Highly recommend the platform.