The switch just changes shift points on the tranny.
Set it for POWER and take off, watch the tach to see at what RPMs it shifts from 1st to 2nd, 2nd to 3rd, etc.
Then do the same (accelerate at the same rate as before) in the ECONO mode. The shift points should be different, and you know it's working.

- seen in FOUR WHEELER mag July 2006 & OFF-ROAD mag Feb 2007 -
'84 4Runner ARBed 5.29s F&R,4.7 & 2.28 t-cases,hy-steer,BudBuilt skid,30spl Longs,36" TSLs,Chevys

'83 P/U, Buick 231 V6,Holley 4 bbl,Weiand intake,Downey headers,TH350 w/700R4 gearset