You can also do a rear wheel HP on a G-Tech, but it would be tough to do with an automatic. I've not tried it yet, I'd have to read the instructions again. It will give you your rear wheel HP on the full 1/4 run, but the #'s are very disappointing, on a full run from start to finish I think I was at 265 RWHP. But keep in mind it was recording the full time witch include's the drop in shifting.