I'd be interested in fuel econ & a higher top end.
My cruising speed seems to be 40-45mph and I get @ 11mpg
>From: "D. Dardalis" <dardal@xxxxxxxxxxxxxxx>
>
>At 01:41 PM 1/28/2002 -0600, you wrote:
>> Carl..
>> Minor problem here.. take 2.76 and multiply times .78 You will
>> notice it gives you a really high top end gear, yes, but do you
>> have enough motor to pull it... There is a point of diminished
>> returns... That being if you have not enough motor to pull the
>> weight of the auto then you must compensate by giving MORE gas,
>> hence, lower mileage..
>This turns out into a popular subject. An additional comment to Robb's
>statement. This combination of 2.76 * 0.78 overdrive = 2.15 ratio would
>result in about 1600-1700 rpm converter output at 65 (don't know your tire
>size, so I am guessing). When you load the torque converter at these low
>speeds climbing a hill, a lot of slippage will result which is nothing but
>direct loss of energy converted to transmission heat. That's where you
>need the lockup converter. The statement about higher engine load
>resulting in poorer fuel economy needs to be a bit more
>explained. Typically, spark ignition engines are more efficient at higher
>loads, for two reasons, the most important of the two is that as the
>throttle opens, the intake restriction diminishes, so the "pumping" losses
>drop. However, if the load of the engine is increased to the point where
>the mixture starts getting rich, then you might start loosing MPG. This
>however happens fairly close to WOT, so it will have to be a very steep
>hill, in which case you have the option to down shift to direct.. The
>super low gear ratios like the 2.15 usually give better MPG's on the
>highway but at the loss of low speed performance and economy. If I paid
>the $ for an overdrive, I 'd rather use it for performance, but one could
>rather choose to maintain a relatively high ratio and use it for
>economy. If in the US though, it might take many years to pay back through
>fuel savings.
>D^2
>
>
_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx
Back to the Home of the Forward Look Network