A different view of fuel economy/efficiency

A different view of fuel economy/efficiency

12-16-2003, 05:14 PM

#1 (permalink)

rbattelle

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Join Date: Nov 2001 Location: Dayton, OH Posts: 10,062 Old Reader's Rigs Gallery

A different view of fuel economy/efficiency

I was thinking about how to indicate efficiency recently, and came up with a sort of specific fuel consumption: fuel economy normalized by unladen weight. So I looked at a few vehicles, took the manufacturer-advertised maximum fuel economy and divided that by the unladen weight. Specifically, the formula I used was (1/MPG)/weight*10000 (the factor 10000 is just to make the result a little easier to look at). Here's what I found:

Vehicle - MPG - Weight - SFC

2003 Ram 3500 HO Cummins - 18.6 - 6945 - 0.0774
2003 Ram 1500 Hemi 4x4 SWB - 17.0 - 5270 - 0.1116
Honda Civic 2dr VTEC - 38 - 2657 - 0.0990
Honda Insight - 66 - 1975 - 0.0767
Toyota Prius - 60 - 2890 - 0.0577

Lower SFC is better. The 3500 Cummins is my own personal vehicle, and instead of using the best possible economy, I used my lifetime average after 15000 miles (note my best economy ever was 20.6 for a full tank). This handicaps the Cummins a bit. Notice that the 3500 gets about the same SFC as a Honda Insight (a fancy Hybrid).

__________________
2003 3500 QC SRW SWB 4X4 3.73 HO/NV5600. Built 2/28/03.
Isspro boost, oil press., oil temp, post-turbo EGT, Wet Okole seat covers, Line-X, Integral OBD-II, Fastcoolers, DSG Idler, Custom Fuel System
@80188 mi/ 2302hr, 19.1 mpg

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