Exhaust Manifold Coatings

Continuing the look at exhaust manifold surface temperatures, the latest check is of the stock exhaust manifolds with Swaintech white lightning coating.  I like the Swaintech product because the advertised thickness of the material is greater than other similar products.  My understanding is that the thickness of a ceramic coating is essential to  performance, with a thicker coating being more likely to perform better.

Swaintech coated stock Audi B5 S4 exhaust manifolds Swaintech coated exhaust manifold close up

Swaintech coated exhaust manifold close up
Swaintech White Lightning Coating


To check the exterior surface temperature of the exhaust manifold I am using an IR thermometer.

Emissivity is assumed to remain constant between different surface coatings, this may be an incorrect assumption and could result in erroneous readings if it is an invalid assumption.

The manifold is at ambient temperature for the beginning of the test, and then the engine is started and allowed to idle for ten minutes, making surface temperature readings every minute.

Repeat-ability of the measurements suffer due to the location of the exhaust manifold as well as the manner in which the manifold heats up, shown below.

IR images of exhaust manifold heating
IR images of exhaust manifold heating

Sampling the exterior surface at the same location each time is difficult, but overall the trends should be indicative of how the differently coated manifolds heat up.  To help achieve better results the readings were made twice for each coating.


Shown below are the average results for each coating type:

chart of exhaust manifold coating with swaintech white lightning

The next chart illustrates the individual readings for each coating type:

chart of average exhaust manifold temperature with ceramic coatings


Under these test conditions and assumptions the ceramic coatings are shown to reduce the rate at which the external temperature of the exhaust manifold increases as recorded by an IR thermometer.  The Swaintech  white lightning coating provides an additional benefit as compared to a thinner, black colored,  alternative ceramic coating.

These results do not give proof of how the different coatings perform over an extended period of time, or under normal driving conditions.