A friend of mine gets a 40% discount from snap-on thru school so i was going to get a tourque wrench from him. While looking on there site i noticed some of the are plus or minus 2% accuracy while some are plus or minus 4% clockwise and plus or minus 6% counter-clockwise. How big of a deal is 4%. the one im looking at goes form 5-75ft/lbs. so assuming im tourqing somethign to 75ft'lbs how big of a deal is it if im off by 3 ft/lbs (4%)?