We (DAP and I) had many questions about this awhile back. We contacted mustang and this is their responce.

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Dave,
>
> The weight entered into the software can have an effect on the HP/Torque numbers, sometimes 10% to 15% although it is usually less than 5% variation. The weight in the look-up table should be used for purposes of repeatability during return visits by the same vehicle, but, if you want accurate 1/4 mile sprint times you should use the actual vehicle weight with driver weight added. FYI, the weights in the look-up table assumes a full tank of gas and driver of 200Lbs, rounded to the nearest 25Lbs. The HP @ 50mph for an Audi S4, 2.7L is 12.9.
>
>
> Regards,
>
>
> Mustang Dynamometer
> 2300 Pinnacle Parkway
> Twinsburg, OH 44087
> www.mustangdyne.com
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