E30 M3: 1,202 kg/220 hp = 5.46 hp/kg

E36 M3: 1,461 kg/286 hp = 5.11 hp/kg

Wt:HP ratio 5.11/5.46 = 0.94 (or a 6% decrease in the wt:hp ratio in the E36 in relation to the E30)

------------------------------------------------------------------------------------------------------------

E46 M3: 1,571 kg/343 hp = 4.58 hp/kg

Wt:HP ratio 4.58/5.11 = 0.90 (or a 10% decrease in the wt:hp ratio in the E46 in relation to the E36)

------------------------------------------------------------------------------------------------------------

E92 M3: 3.8 kg * 420 hp = 1,596 kg (Wt/hp source: Official BMW M3 International Launch information (Please see attachment page 17). Yes, the official “unladen” weight is 3704 or 1,683 kg which doesn’t quite mesh with the equally “official” 3.8kg-to-1hp.

)

Wt:HP ratio 3.8 kg/4.58 kg = 0.83 (or a 17% decrease in the wt:hp ratio of E92 in relation to the E46)

------------------------------------------------------------------------------------------------------------

Over four generations the weight-to-horsepower ratio has been reduced by 6%, 10%, and 17% while horsepower has increased by 30%, 20%, and 22%. At the same time, weight has increased by 22%, 8%, and 2%.

It is probably a safe bet that the next generation M3 will follow tradition by being a better performer than the previous generation. Not knowing the extent to which performance improvement is targeted poses the greatest obstacle to getting a handle on this "puzzle". To wit: Will the next generation attempt to match the massive performance increase over a previous generation as was achieved with the E92M3 or will the performance increase be more akin to that of the E36M3 vis a vis the E30M3?

Scenarios

In order improve the kg/wt ratio of the 5th generation M3 at what would be a historical average – (6%+10%+17%) / 3 = 7.67%) – such would be achieved by increasing horsepower to 455 with no weight increase whatsoever would result in a “new” kg:hp ratio would be 3.51kg/hp.

If weight does increase as many suspect that it will, including myself, and let’s suppose the increase is a mere 25kg, an additional 17 horsepower would be needed to offset the weight increase while retaining a 7.67% decrease in weight to horsepower that results in the improved 3.51kg/hp.

On the other hand, if the design team of the next generation M3 targeted a replication of what was achieved with the E92 versus the E46 – a combination of minimal weight increase and massive power increase – the next generation would gain approximately 30 kg to weigh in at 1,628 kg (+2%) while power would increase by 92hp to 512hp (+22%), and that translates into a 3.18 kg/hp ratio.