All depends on the settings. At the same elevation, all dynojets should ready very very similar (in fact I've witnessed the same car on 3 east cost dynos on the same day make the same power on all 3 dynojets). All the others, all depend on the operator. Dynojet has automated environmental readings that are pretty much foolproof, so they all read the same. All other types of dynos require input of form or another and depend on the operator. I've seen the same mustang dyno read 50 high (compared to dynojet) on one car and then read 30 low on another.