Charlie -

No, I haven't measured it, but the electrical resistance/length/voltage/current relationship is available in several calculators to save the effort of doing the mathematical calculations.

This calculator is based on 140*F, but it's what I used for the calculations:

Voltage Drop Calculator

Here's another one that shows the voltage drop to be 9.73%, but it's provided by the American Boat and Yacht Council and I assume it references marine grade wire... which has about a 10% higher size/load factor, partly because of the hot environment in an engine compartment and degradation in a salt environment:

ABYC Amperage Tables

This one is also from a marine source and shows only a 4.7% loss.... but at 30*C:

Manray marine

Here's another from Advanced Power Products - a supplier of my Concorde AGM battery - same as the ABYC results above - not surprising, since the solar cells are commonly used in marine storage applications:

Advanced Power Products

I don't know what the Bosch pumps draw.... and I'm not saying the Denso pump won't run at a reduced voltage, but if it does, it'll draw more amperage - and how much more is an unknown to me. The pump does run more efficiently at higher voltage.... and particularly at that run length and with the small (5/16" O.D.) fuel line, I just want to take that worry out of the equation..... once bitten, twice shy.

I've never run more than AWG14 either, but this time I dang sure will. <img src="/forums/images/graemlins/kewl.gif" alt="" /> It might have been simpler/better to increase the fuel supply line size to 3/8" - maybe I should do that as well.

EDIT:[The above was stated incorrectly - voltage reduction won't cause an increase in current - amperage will instead drop, but so will flow. Also, "efficiency" is used incorrectly - "increased supply" was the intent with higher voltage.... sorry for the confusion]:EDIT

Frank