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Originally posted by Sigma@Aug 2 2005, 04:31 PM
The Drag-Limited Top Speed of the 2.5L SVT Contour is 143mph.  Any higher than that is just speedometer inaccuracy, which at those speeds can be as much as 10%.  Modern hyper-accurate navigation systems really show the inaccuracy of speedometers at high speed when you get up there in the MPH.
 
For proof of that, do the math.  The CSVT tops out at 6310 RPMs, at 143mph.  The picture shows the Tach virtually dead-on what would be 6310RPMs but it's MPH is quite a bit more -- the Speedo is wrong.  With the gear ratios that the CSVT has it's not physically possible to be going 150mph at 6300RPMs.

The Drag-Limited Top Speed of the 3.0L Mazda6s is 142mph, actually a tick lower than the CSVT. 

Both cars have the same CoD.  So what's the difference?  Gear ratios. 

The 5th gear on the CSVT is a 0.77:1 with a Final Drive of 4.06:1, giving it a 3.13:1 Fifth Gear.

The 5th gear on the 6s is a 0.73:1 with a Final Drive of 4.13:1, giving it a 3.01:1 Fifth Gear.

The theoretical top speed of the 6s is slightly higher because of the lower 5th gear.  But the actual top speed is just a hair lower because the lower gear ratio can't overcome the drag at those speeds.  The extra power that the 6s has only goes so far -- particularly when it's pulling an extra 200lbs or so.
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Mmm good point. :thumbup:
 
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