For 4x setup with HQ 50x43x3.
#!/usr/bin/env gnuplot
set terminal png size 1600,1200
set output "eco-1900.png"
set yrange [0:140]
set xrange [0:7000]
set ylabel "current, A"
set xlabel "thrust, G"
set ytics 5
set xtics 500
set grid xtics ytics
$emax1700 << EOD
0.9 0
2.6 300
5.1 500
8.5 700
26.9 1580
EOD
$emax1900 << EOD
1.1 0
2.9 300
5.3 500
8.7 700
34 1830
EOD
$emax2400 << EOD
1.5 0
4.5 300
9.2 500
14.1 700
32.1 1370
EOD
set arrow from 0,80 to 7000,80 nohead
plot \
"$emax1700" using ($2*4):($1*4) with lines title "emax1700", \
"$emax1900" using ($2*4):($1*4) with lines title "emax1900", \
"$emax2400" using ($2*4):($1*4) with lines title "emax2400"
pause -1