Tensile strength of aluminum exceeds steel by a significant amount, if my memory serves correctly. I believe there are some aluminum alloys that rival titanium. The biggest benefit though is the fact that you can make an aluminum alloy that is as "strong" as some of the best steel alloys, except it is far lighter and much more corrosion resistant.
in absolute strength, not even close, for a variety of reasons. aluminum does tend to have a better strength/weight ratio (or more properly, strength/density).
for reference, an aluminum alloy from Kobe Steel holds the ultimate tensile strength (UTS) record at 780 MPa.
alternatively, a classic high strength steel like 4340, which has been around for ages, has a UTS in the area of 1600-1800 MPa.
The 18-Ni maraging steels series can have UTS's in excess of 2000 MPa.