Sorry to say, on higher mileage vehicles (in particular) it is a crapshoot. The soot in the tailpipe test is invalid when it comes to vehicles that have 150k miles or more on them (and in some cases, on some vehicles, far fewer miles), they ALL have some soot in the tailpipe. Also, many used vehicles on the market have been started and moved many times in a short period of time, never warmed-up, and running rich at every cold start. These vehicles will often display considerable soot buildup in the tailpipe.
IMO, the best advice that has been given is to get some help to drive the vehicle for you while you follow and observe. You can tell a lot about a vehicle by just observing it when it is going down the road.
IMO, the best advice that has been given is to get some help to drive the vehicle for you while you follow and observe. You can tell a lot about a vehicle by just observing it when it is going down the road.
Last edited: