When you put LED bulbs in old T8-T12 fixtures, you are still running the ballast, which is about 10W, so you have to add that on to get real numbers for total wattage. They do sell bulbs that you can put into the old fixtures that require you to remove the ballast, but they are pretty expensive.
Costco sells a whole 4 ft. fixture with two tubes that only draws 38W, compared to a T12 fixture that draws about 90W. I am pretty sure they put out just as much or more light than the T12, and two of them use less watts than one T12 fixture. They were recently on sale for $30 each, and are $36 regularly. I posted some pics of the spec sheet and side by side comparison on the Registry:
Garage Lighting