I just installed an Autometer z-series exhaust temperature guage. I mounted the probe in the down pipe about 6 inches from the elbow (no warrenty problems, or potential installation problems). My temps range from 500-600 degrees cruising empty (have yet to tow since guage was installed), up to 750 when I really put the hammer down. As for cool down, temp drops to 300 in about 1 minute, to a low of 250 after about 5 minutes. How do these numbers sound compared to a pre turbo or elbow probe mounting location? By the way, the engine is stock except for m. e. kit from Geno's.