The three most important pieces of information that you need to know while driving are boost pressure, exhaust gas temperature (EGT) and transmission temperature.
Boost pressure indicates the amount of load put on the turbo. It also is a great indicator of how the turbo is performing. The pressure may be low if the intercooler piping is leaking or the turbo is beginning to fail. EGT indicates the amount of engine load. There can be times where you're on a pull and simply are in the wrong gear. When pulling a load, the transmission can shift into over drive too soon causing the EGT's to go way up without the aid of boost pressure. This is easy to see in the gauges and feel in the pedal. In these situations, you can pop it out of O/D and get the engine rpm up. When you do, the boost comes up and the EGT's actually fall.
The EGT gauge measures the temperature of the exhaust going into the turbo. We recommend installing the thermocouple before the turbo, in the driver's side exhaust manifold. There can be up to 300-degree difference between the exhaust manifold and the down pipe. You can safely run 1250 degrees, but not much more than that. The truck will pull all day long at 1250, but anything over will cause the tips of the turbine blades
to start to glow. Get them too hot and you'll kill the turbo as the blades start to straighten out. There is also a sweet spot, which will enhance your fuel economy. 600 degrees is the peak efficiency point for these engines. Above 600 degrees the engine burns more fuel. Driving by the EGT gauge is like the old vacuum gauges in gas engines a long time ago. Keep the needle in the green for best fuel economy. With your Power Stroke, keep the needle as close to 600 degrees and you'll get the best fuel economy possible. At the end of your driving allow the turbo to cool down to 300 degrees before shutting the truck off.
Transmission temperature might be self explanatory, but it bears repeating. The temperature gauge sender goes in the side of the transmission case and measures the temp of the fluid. In normal driving, you should see temperatures around 160-170 degrees. The harder you're pulling, the higher the temperature will get. So if you're pulling a load, you might see 180-190 degrees. If you're pulling the Queen Mary up the side of a mountain, then you might see 210. This is the do-not-exceed point for transmission temperature. If you get to the top of that hill and the transmission is at 210, that is fine, it'll cool down as you level off. If you're marching up the side of that mountain and reach 210 degrees half way up, it's time to back off. Simply slow down and wait for the temperatures to cool back off.
So keep an eye on what's going on under your hood without taking your eyes off the road. Install a set of our gauges today, and help your truck live a longer tomorrow.