How accurate are the OBDII scanners at estimating horsepower and torque? Obviously its better to just get a chassis dyno test but how far off (if used correctly) are the scanner estimates?

I don't think OBDII scanners can estimate hp. AFAIK, they can only monitor the cars sensor functions. Could be wrong though. :dunno

I don't think OBDII scanners can estimate hp. AFAIK, they can only monitor the cars sensor functions. Could be wrong though. :dunno

Alot of them do 'try' and estimate hp numbers, just as the Gtech type products do, but at least they supposedly specialize in generating those types of numbers, unlike the scantools most of which do it as an adjunct to their main purpose. Ive seen results swing widely from them to a real dyno. Maybe some folks have had verified good power estimating results with theirs though. I dont know.

Auto Enginuity has a whole program set to estimate HP...it uses speed rpm and weight of the car...

Auterra has a similiar funtion for hp/ tq. I always wondered if it was accurate.

Never tried my digimoto Dyno option. Can't find a stretch of road to go wide open in 3rd gear. :stickoutt

Yea I was looking at the ProScan thing. Plus it can tell you your 0-60 times and 1/4 times which i think is pretty cool and should be really accurate. But for the HP they use your acceleration and weight numbers for a given rpm range.....in theory it should be accurate...but there are alot of outside factors. I just want to know if anyone on here has measured their HP at a chasis dyno and used one of these tools to see how close they were.