6th is not a cruising gear in the Mazdaspeed Miata.

The car redlines in 5th at 107 and 6500 rpm, and 6th, while an
overdrive, gets you to 127. The torque on the vehicle is ok on the
lower end, but the fun does not start until 4000 rpm (See
http://www.flyinmiata.com/tech/dyno.asp under 2006 MX-5 versus 2004
Mazdaspeed for the graph)

To get more torque at the low end, you need more displacement, and a
differently geared transmission. For example, the Pontiac Solstice
has a 2.3 liter engine that is rated at 26 more ft-lbs than the NC
mill. That car hits its published 120 mph top speed at 6200 rpm in
4th gear. 5th would reach that same 120 top speed at a lower rpm, so
it is a true "cruising" gear

On Fri, 21 Apr 2006 01:08:10 -0400, "Chuck" >
wrote:

>The trouble is -- the market! Flat country = lower RPM needed. (Australia)
>US- not so flat- higher RPM.
> A stiffer 5th or 6th gear also causes a higher torque load, and higher
>combustion chamber temperature.
>(Not the favorate of warrenty sellers)
> wrote in message
m...
>> Agreed, 6th is a cruising gear. It shouldn't need high revs. If you need
>> to be accelerating hard in overdrive, you need to rethink your driving
>> habits and learn to downshift. That was one of my few major complaints
>> about my '01.

>> >>
>> >> Horsepower = torque * revs/minute * minute/60 seconds * 2*pi * 1/550
>> >> Horsepower = torque * revs/minute * 1/5252
>> >>
>> >> In a very simple way:
>> >>
>> >> Suppose your car requires 100 hp to move along at 90 mph.
>> >>
>> >> A v-8 rated at 300 ft-lb at 2000 rpm will be producing 114. An
>> >> engineer will pick the gearing and rear end to produce the right rpm
>> >> at the wheels.
>> >>
>> >> A smaller 4 cylinder engine, producing 140 ft-lbs or torque would have
>> >> to turn nearly 4300 rpm to produce the power necessary to move the
>> >> same car at the same 90 mph.
>> >>

>>
>>
>