Reading Exhaust Gas Temperature EGT


This may be one of the least understood and most improperly used tuning tools in the aftermarket.

Reading EGT:  So what makes a cylinder hotter/cooler?

We’re looking at are coolest cylinder as our baseline in these tests, is that the right thing to do?  Is the hottest cylinder flowing more air?  If so won’t it make more power if we put more fuel with it?  Isn’t that what we want? If we could, should make the cooler passages flow more air or should we put more fuel in the hotter passages?

Is reading EGT on a wet manifold different than on a dry manifold?  In other words, could our problems on this carb’d manifold not just be airflow, but also fuel atomization?  Whereas with a MPI EFI setup the fuel enters just before the valve and atomizes there so we’re just worried about getting consistent/even air to each cylinder.