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      04-06-2007, 06:07 PM   #1
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swamp2's Avatar

Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

iTrader: (1)

M3 vs M5 0-60 - GEARING!

Guys if you missed it we have all of the gear ratio information for the new beast including the final drive. This makes for some fun spreadsheeting! As you probably know the E46 M3 did not have all that great of a power to weight ratio. It did still manage a pretty impressive 0-62 (5.2 s quoted by BMW but many found more like 4.8 s). It accomplished this through a few things but mostly by low gearing (torque multiplication). The new M3 has a significantly larger final drive than than M5 3.846 vs. 3.62. Taking into account each gear ratio, the final drive, the wheel size, an estimate of drivetrain loss and weight the M3 has a significant advantage in acceleration at almost all rpms in 1st gear (the M5 gets a very slight advantage from 6k- 7k rpm from its pronounced torque peak there).

The % advantage looks something like this:
  • 3000 12%
  • 3500 12%
  • 4000 9%
  • 4500 6%
  • 5000 5%
  • 5500 3%
  • 6000 -3%
  • 6500 -2%
  • 7000 -1%
  • 7500 1%
  • 8000 5%
  • 8250 8%
I figured there would be wheel spin up to at least 3k rpm, maybe higher with a good launch. Redline in 1st gear puts the new M3 at 42 mph, the M5 at 46 mph. The acceleration advantage goes to the M5 across the board at all engine speeds during a maximum acceleration run in all other gears.

(Note: Things missing in my fairly simple analysis: rolling resistance and air resistance. These should be fairly close though for both vehicles)

OK what's next? If that was it the M3 would be the clear winner. The traction from the M5s 285 tires and the .3 - .4 second advantage from SMG vs 6MT on the 1st to 2nd gear shift will also make quite some difference. It is nearly impossible to estimate how much the stronger acceleration in the M3 will be offset by these advantages.

Put some 295 or 305 width tires on the M3 and get it with the dual clutch system and I'd place my bets on the M3 besting the M5 0-60 mph. As it is released, 6MT and stock tires it is going to be really interesting.