The problem with a 5 gas analyzer is speed. They typically takes 5-15 seconds per reading. Speed isn't an issue for a static dyno. But for an inertial dyno and road tuning, you need better instrument response.

The issue is that lambda is always changing in road/track situation and inertial dynos. Finding out how the vehicle sort-of averaged the last 10 seconds or so is just not that useful. Of course, we're biased. From our point of view, instruments that are inherently wrong whenever lambda is changing and take .5 to 1.5 seconds to read correctly when it stabalizes are also too slow...

Seriously, although it still isn't that cheap, calibrated gas is probably the way to go if you are really concerned with accuracy. Even if you bought a five gas analyzer, you would normally use calibrated gas to maintain it. You can also use the tanks to check for pressure related errors.

Just remember that room temp, steady pressure gas is a best case. Depending on the controller design, in car errors will typically be 2 to 5 times higher.

-jjf

 

It is actually pretty hard to make most widebands read artifically rich. You can do it with ours if you free air calibrate in exhaust fumes, and you can do it with current based widebands with back pressure, but normally it is much easier to get the instruments to error on the lean side.

-jjf