Common manufacturers and vehicle lines that use the BKR6EIX(or similar BKR6E-series plugs) often include: BMW: Various models, particularly older 5-series (E34, E39), 7-series (E38), and Z3 models with certain engines (e.g., M50, M52, M60, M62 engines).
I've used this product before and know the quality and performance that it delivers. At the price offered this is definitely a case of one man's discard being another man's treasure.
The first thing I noticed with these Iridium spark plugs was how the engine ran smoother, The acceleration through the gears has improved as well. As for the fuel economy, I haven't used a full tank up yet but my fuel guage is sitting higher than usual with the amount of km's I done. These plugs are good value for money