[Citation Needed]
I know of old benchmarks (pre Crankshaft) that showed the interpreter being faster than V8, but my own tests using the same benchmarks from the computer language shootout show V8 to be about 1.5x faster than luaJIT now.
I did some searching, and the most recent (though still way out of date) comparison I could find was this: http://attractivechaos.github.com/plb/