For the first half 2011, free cash (usage) flow was $(48) million, after total rental and non-rental capital expenditures of $425 million. By comparison, free cash flow for the first half 2010 was $107 million after total rental and non-rental capital expenditures of $186 million. Free cash flow for the first half 2010 included the receipt of a $55 million federal tax refund.
The company has updated its outlook for full year free cash flow to a range of $5 million to $10 million, including net rental capital expenditures of $450 million to $500 million. Gross rental purchases are now estimated to be approximately $650 million.
The size of the rental fleet was $4.18 billion of original equipment cost at June 30, 2011, compared with $3.79 billion at December 31, 2010. The age of the rental fleet was 46.5 months on a unit-weighted basis at June 30, 2011, compared with 47.7 months at December 31, 2010.
Return on Invested Capital (ROIC)
Return on invested capital was 4.6% for the 12 months ended June 30, 2011, an increase of 2.0 percentage points from the same period last year. The company's ROIC metric uses after-tax operating income for the trailing 12 months divided by the averages of stockholders' equity (deficit), debt and deferred taxes, net of average cash. To mitigate the volatility related to fluctuations in the company's tax rate from period to period, the federal statutory tax rate of 35% is used to calculate after-tax operating income.