Only time I run mine wide open is when I'm cutting down heavy or thick stuff that needs it. Rest of the time its half throttle at best and feathering it as I go. No need to run it harder if it's cutting down what you're aiming at. Had an old timer small engine mechanic (one of the best in the business in the N. Phoenix area, 30 years worth of reputation and knowledge running his own shop at the time) tell me decades ago, no reason to run one that hard, it's only hard on the equipment. Wastes fuel, wastes trimmer line, hard on the engine, hard on the shaft and bearings, and doesn't do any better of a job.