Audi S8 vs BMW Alpina B5

What's the difference?

Big sedans are not in vogue at the moment and huge luxury sedans were on the way down before the humble Commodore and Falcon departed the upper end of the sales charts. The Germans, who have always done a spectacular job of these flagship sedans, cheerfully persist with these cars.

Absolutely loaded with fascinating technology that bleeds its way down to the more mainstream models, they represent the zenith of the brand's innovation and style. The A8 is certainly that.

What it isn't, is particularly sporty, but after two years since its launch, V8 power has reached the fourth-generation super-sedan to deliver the latest iteration of the iconic S8.

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?