Used to check/reset the tracking on my truck. It depends totally if you have a clear view across both ends of the irons without any obstructions such as the engine, subframe or whatever. I was lucky in that it only just cleared my sump so I could take an accurate measurement. And then worked out really well (mine is parallel anyway so measurement was easy.) Very well made and proper stainless steel too. The tapes are a little cheap but they do the job perfectly and for this price, it would cost you at least twice as much at a garage.