This is incorrect. You are confusing a "tax deduction" from a "tax credit". A credit is money in your pocket. Whatever the credit is, that's what your taxes are reduced by. A deduction reduces your taxable income by that amount, but your taxes are then only reduced by that deduction times your tax rate. So you only get back a small fraction of the deduction. In this case, getting the credit on off-road fuel use (whether it is for power tools, or vehicles not driven on public highways, or generators, or whatever) will always get you more money back.