BMW Alpina B5 vs Audi S4

What's the difference?

The BMW Alpina B5 Bi-Turbo is not actually a BMW. Not according to the German Federal Motor Transport Authority, at least.

Nope, the modifications applied by tuning house Alpina to the 5 Series are deemed so significant that if you open the bonnet and look inside the engine bay, you'll see that the BMW VIN has been struck through twice and an Alpina vehicle number stamped underneath it. 

The B5 is not the first model to be recognised in this way, either; the German government has recognised Alpina as a seperate car manufacturer since 1983.

The B5 has other ‘B' siblings, too. There's the B3 S Bi-Turbo, which is based on the BMW 3 Series, the B4 S Bi-Turbo (the BMW 4 Series) and the B7 Bi-Turbo (I don't need to tell you what this is based on, right?) which I've reviewed, too.

So just what has Alpina done to this unsuspecting BMW 5 Series? Is it really worth the extra money? How does the B5 compare to an M5? Could it actually be superior? And did they really take the speed limiter off to let it warp-speed to beyond 300km/h?

Audi would probably prefer you not to realise this, but the five distinct versions of S4 and S5 on the market all pertain to a single performance and equipment formula spread across five different bodystyles. 

Yes five, and this has been the case for more than a decade, with the S4 sedan and Avant wagon, A5 two-door Coupe, convertible Cabriolet and five door liftback Sportback all representing vastly different shapes for you to choose from, with the same underpinnings. This simply echoes the A4 and A5 ranges they’re based on of course, and BMW clearly thought it was a good idea too, given the 3 and 4 Series ranges were split into individual lines at the start of last generation.

Mercedes-Benz offers a similar array, minus the liftback, but is happy to wrap the whole lot under the C-Class label. 

So, given that the A4 and A5 range scored a mid-life update a few months ago, it’s only logical that the changes flow on to the performance S4 and S5s, with the top-tier RS4 Avant following suit. 

We’ve covered the latter in October, and now it’s the turn for the former, and CarsGuide was among the first to drive the updated S4 and S5 ranges at their Australian media launch last week.