Originally Posted By: Rolla07
Range on the Elm 327 is apparently 30 feet...(bluetooth range) guess it depends on the environment though..
The 'Elm 327' part doesn't have anything to do with the range, and these are all clones of the 327 rather than a branded product.
The ones I've taken apart have all used serial bluetooth modules with a CSR chipset and large (for bluetooth) circuit board antenna -- exactly the ones you can find on FleaBay for $8 or so. They'll have good range, but perhaps only line-of-sight. Expecting them to reach 30 foot when tucked under the dash is... optimistic.
I haven't taken apart the newer compact readers, which don't looks as if the would support an off-the-shelf module.
An inexpensive solution is to buy an OBD2 extension cable for $5-$10 to move the reader out from under the dash.