Many users feedback they prefer mini elm327 Bluetooth with Switch (for torque and iPhone) to the old version Elm327. One of the deciding factor is that this type elm327 is built in one ON/ Off switch.
Let’s have a look, what is the on/off button for?
-no reason why not this one is great over others are you can just leave it plugged in hidden away and turn it on when required.
One without an on/off button would require removal not to drain the battery as the obd port has constant power
– For the switched version. It’s much more convenient (just leave it in place) and will not drain you battery. Plus its always there when you need it and you’re less likely to loose it.
-As far as the ELM327 interface go I bought one of these a few years about, but there a bit bulky compared to others on ebay. I am going to order this one for the sake of on/off switch and size the idea being it can be left in place.
Elm327 with switch for torque at $19 (Item No. SC157), it suports TORQUE software for Android system cell phone, OBDscope software for Symbian system cell phone, PPC(Windows Mobile) system cell phone, ScanMaster-ELM for PC etc.
New Super Mini ELM327 Bluetooth with Switch at 11.99 free shipping (Item No. SC158), it works with IPhone.